[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:01.00,Default,,0000,0000,0000,,
Dialogue: 0,0:00:01.00,0:00:02.00,Default,,0000,0000,0000,,The following content is\Nprovided under a Creative
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Dialogue: 0,0:00:13.00,0:00:15.00,Default,,0000,0000,0000,,hundreds of MIT courses,\Nvisit MIT OpenCourseWare
Dialogue: 0,0:00:15.00,0:00:17.00,Default,,0000,0000,0000,,at ocw.mit.edu.
Dialogue: 0,0:00:17.00,0:00:48.00,Default,,0000,0000,0000,,PROFESSOR: OK, let's just\Ntake 10 more seconds on
Dialogue: 0,0:00:48.00,0:01:02.00,Default,,0000,0000,0000,,the clicker question.
Dialogue: 0,0:01:02.00,0:01:09.00,Default,,0000,0000,0000,,OK, 76, I think that says,\N%, which is not bad, but
Dialogue: 0,0:01:09.00,0:01:12.00,Default,,0000,0000,0000,,we should be at 100%.
Dialogue: 0,0:01:12.00,0:01:17.00,Default,,0000,0000,0000,,So, when you're past the\Nequivalence point, so you've
Dialogue: 0,0:01:17.00,0:01:20.00,Default,,0000,0000,0000,,converted all of your weak, in\Nthis case, acid to its
Dialogue: 0,0:01:20.00,0:01:25.00,Default,,0000,0000,0000,,conjugate base, and because it\Nwas a weak acid, the conjugate
Dialogue: 0,0:01:25.00,0:01:28.00,Default,,0000,0000,0000,,base is going to be a weak\Nbased and so it's not
Dialogue: 0,0:01:28.00,0:01:31.00,Default,,0000,0000,0000,,contributing a whole lot it'll\Nmake the solution basic, but
Dialogue: 0,0:01:31.00,0:01:35.00,Default,,0000,0000,0000,,it's nothing compared to adding\Nstrong base in there.
Dialogue: 0,0:01:35.00,0:01:38.00,Default,,0000,0000,0000,,So even though you have\Nthe weak base around, at
Dialogue: 0,0:01:38.00,0:01:41.00,Default,,0000,0000,0000,,this point it's really\Na strong base problem.
Dialogue: 0,0:01:41.00,0:01:45.00,Default,,0000,0000,0000,,So you would calculate this by\Nlooking at how many mils of the
Dialogue: 0,0:01:45.00,0:01:50.00,Default,,0000,0000,0000,,strong base you've added past,\Nand figure out the number of
Dialogue: 0,0:01:50.00,0:01:54.00,Default,,0000,0000,0000,,moles that there are, and\Ndivide by the total volume.
Dialogue: 0,0:01:54.00,0:01:57.00,Default,,0000,0000,0000,,So this was like one of the\Nproblems on the exam, and one
Dialogue: 0,0:01:57.00,0:02:00.00,Default,,0000,0000,0000,,thing that I thought was\Ninteresting on the exam is that
Dialogue: 0,0:02:00.00,0:02:03.00,Default,,0000,0000,0000,,more people seemed to get the\Nhard problem right than this,
Dialogue: 0,0:02:03.00,0:02:05.00,Default,,0000,0000,0000,,which was the easy problem.
Dialogue: 0,0:02:05.00,0:02:10.00,Default,,0000,0000,0000,,So we'll see on the final,\Nthere will be an acid based
Dialogue: 0,0:02:10.00,0:02:14.00,Default,,0000,0000,0000,,titration problem on the\Nfinal, at least one.
Dialogue: 0,0:02:14.00,0:02:18.00,Default,,0000,0000,0000,,So let's see if we can\Nget, then, the easy and
Dialogue: 0,0:02:18.00,0:02:20.00,Default,,0000,0000,0000,,the hard ones right.
Dialogue: 0,0:02:20.00,0:02:22.00,Default,,0000,0000,0000,,So you've mastered the hard\Nones and let's see if you can
Dialogue: 0,0:02:22.00,0:02:29.00,Default,,0000,0000,0000,,learn how to do the easy ones\Nas well for the final exam.
Dialogue: 0,0:02:29.00,0:02:33.00,Default,,0000,0000,0000,,OK, so we're going to continue\Nwith transition metals.
Dialogue: 0,0:02:33.00,0:02:37.00,Default,,0000,0000,0000,,We were talking about crystal\Nfield theory and magnetism, and
Dialogue: 0,0:02:37.00,0:02:42.00,Default,,0000,0000,0000,,you should have a handout for\Ntoday, and you should also have
Dialogue: 0,0:02:42.00,0:02:48.00,Default,,0000,0000,0000,,some equipment to make models\Nof orbitals and coordination
Dialogue: 0,0:02:48.00,0:02:51.00,Default,,0000,0000,0000,,complexes -- these\Nare not snacks.
Dialogue: 0,0:02:51.00,0:02:59.00,Default,,0000,0000,0000,,They can be snacks later, right\Nnow they're a model kit.
Dialogue: 0,0:02:59.00,0:03:05.00,Default,,0000,0000,0000,,All right, so I'm going to\Nintroduce you to some terms
Dialogue: 0,0:03:05.00,0:03:09.00,Default,,0000,0000,0000,,that we're going to come back\Nyou at the end of today's
Dialogue: 0,0:03:09.00,0:03:12.00,Default,,0000,0000,0000,,lecture, and then we're going\Nto talk about the shapes of
Dialogue: 0,0:03:12.00,0:03:14.00,Default,,0000,0000,0000,,coordination complexes.
Dialogue: 0,0:03:14.00,0:03:18.00,Default,,0000,0000,0000,,So, magnetism.
Dialogue: 0,0:03:18.00,0:03:21.00,Default,,0000,0000,0000,,So we talked last time, before\Nthe exam, if you remember,
Dialogue: 0,0:03:21.00,0:03:25.00,Default,,0000,0000,0000,,about high spin and low spin,\Nunpaired electrons and
Dialogue: 0,0:03:25.00,0:03:26.00,Default,,0000,0000,0000,,paired electrons.
Dialogue: 0,0:03:26.00,0:03:29.00,Default,,0000,0000,0000,,Well, compounds that have\Nunpaired electrons are
Dialogue: 0,0:03:29.00,0:03:33.00,Default,,0000,0000,0000,,paramagnetic, they're attracted\Nby a magnetic field, and those
Dialogue: 0,0:03:33.00,0:03:36.00,Default,,0000,0000,0000,,where the electrons are paired\Nare diamagnetic are repelled
Dialogue: 0,0:03:36.00,0:03:38.00,Default,,0000,0000,0000,,by a magnetic field.
Dialogue: 0,0:03:38.00,0:03:43.00,Default,,0000,0000,0000,,So you can tell whether a\Ncoordination complex is
Dialogue: 0,0:03:43.00,0:03:46.00,Default,,0000,0000,0000,,paramagnetic or diamagnetic,\Nyou can test the magnetism,
Dialogue: 0,0:03:46.00,0:03:51.00,Default,,0000,0000,0000,,and that'll give you some\Ninformation about the electron
Dialogue: 0,0:03:51.00,0:03:55.00,Default,,0000,0000,0000,,configuration of the d orbitals\Nin that coordination complex.
Dialogue: 0,0:03:55.00,0:03:59.00,Default,,0000,0000,0000,,And that can tell you\Nabout the geometry.
Dialogue: 0,0:03:59.00,0:04:02.00,Default,,0000,0000,0000,,And so you'll see that by the\Nend we're going to talk about
Dialogue: 0,0:04:02.00,0:04:06.00,Default,,0000,0000,0000,,different types of energy\Norbitals when you have
Dialogue: 0,0:04:06.00,0:04:07.00,Default,,0000,0000,0000,,different geometries.
Dialogue: 0,0:04:07.00,0:04:11.00,Default,,0000,0000,0000,,So why might you care about the\Ngeometry of a metal center.
Dialogue: 0,0:04:11.00,0:04:15.00,Default,,0000,0000,0000,,Well, people who study proteins\Nthat have metal centers care a
Dialogue: 0,0:04:15.00,0:04:17.00,Default,,0000,0000,0000,,lot about the geometry of them.
Dialogue: 0,0:04:17.00,0:04:20.00,Default,,0000,0000,0000,,So let me just give\Nyou one example.
Dialogue: 0,0:04:20.00,0:04:25.00,Default,,0000,0000,0000,,We talked a lot about energy in\Nthe course this semester, so we
Dialogue: 0,0:04:25.00,0:04:28.00,Default,,0000,0000,0000,,need catalysts for removing\Ncarbon monoxide and carbon
Dialogue: 0,0:04:28.00,0:04:31.00,Default,,0000,0000,0000,,dioxide from the environment.
Dialogue: 0,0:04:31.00,0:04:35.00,Default,,0000,0000,0000,,And nature has some of these --\Nthey have metal cofactors and
Dialogue: 0,0:04:35.00,0:04:38.00,Default,,0000,0000,0000,,proteins that can do this, and\Npeople have been interested in
Dialogue: 0,0:04:38.00,0:04:41.00,Default,,0000,0000,0000,,mimicking that chemistry\Nto remove these gases
Dialogue: 0,0:04:41.00,0:04:43.00,Default,,0000,0000,0000,,from the environment.
Dialogue: 0,0:04:43.00,0:04:46.00,Default,,0000,0000,0000,,So let me tell you these\Nenzymes are organisms.
Dialogue: 0,0:04:46.00,0:04:52.00,Default,,0000,0000,0000,,And this is pretty amazing,\Nsome of these microorganisms.
Dialogue: 0,0:04:52.00,0:04:55.00,Default,,0000,0000,0000,,So, over here there's one\N-- it basically lives
Dialogue: 0,0:04:55.00,0:04:57.00,Default,,0000,0000,0000,,on carbon monoxide.
Dialogue: 0,0:04:57.00,0:05:00.00,Default,,0000,0000,0000,,I mean that's -- you know\Nalternative sources of energy
Dialogue: 0,0:05:00.00,0:05:02.00,Default,,0000,0000,0000,,are one thing, but that's\Nreally quite a crazy thing
Dialogue: 0,0:05:02.00,0:05:03.00,Default,,0000,0000,0000,,that this guy does.
Dialogue: 0,0:05:03.00,0:05:07.00,Default,,0000,0000,0000,,So, you can grow it up in these\Nbig vats and pump in carbon
Dialogue: 0,0:05:07.00,0:05:11.00,Default,,0000,0000,0000,,monoxide and it's like oh,\Nfood, and they grow and
Dialogue: 0,0:05:11.00,0:05:14.00,Default,,0000,0000,0000,,multiply, and they're very,\Nvery happy in this carbon
Dialogue: 0,0:05:14.00,0:05:16.00,Default,,0000,0000,0000,,monoxide environment.
Dialogue: 0,0:05:16.00,0:05:19.00,Default,,0000,0000,0000,,There are also microorganisms\Nthat live on carbon dioxide as
Dialogue: 0,0:05:19.00,0:05:23.00,Default,,0000,0000,0000,,their energy and\Na carbon source.
Dialogue: 0,0:05:23.00,0:05:27.00,Default,,0000,0000,0000,,And so these organisms have\Nenzymes in them that have metal
Dialogue: 0,0:05:27.00,0:05:30.00,Default,,0000,0000,0000,,centers, and those metal\Ncenters are responsible for the
Dialogue: 0,0:05:30.00,0:05:35.00,Default,,0000,0000,0000,,ability of these organisms to\Nlive on these kind of bizarre
Dialogue: 0,0:05:35.00,0:05:37.00,Default,,0000,0000,0000,,greenhouse gases\Nand pollutants.
Dialogue: 0,0:05:37.00,0:05:41.00,Default,,0000,0000,0000,,So people would like to\Nunderstand how this works.
Dialogue: 0,0:05:41.00,0:05:44.00,Default,,0000,0000,0000,,So microbes have been estimated\Nto remove hundred, a million
Dialogue: 0,0:05:44.00,0:05:48.00,Default,,0000,0000,0000,,tons of carbon monoxide from\Nthe environment every year,
Dialogue: 0,0:05:48.00,0:05:52.00,Default,,0000,0000,0000,,producing about one trillion\Nkilograms of acetate from
Dialogue: 0,0:05:52.00,0:05:53.00,Default,,0000,0000,0000,,these greenhouse gases.
Dialogue: 0,0:05:53.00,0:05:57.00,Default,,0000,0000,0000,,And so, what do these catalysts\Nlook like and these enzymes,
Dialogue: 0,0:05:57.00,0:05:59.00,Default,,0000,0000,0000,,what do these metal clusters\Nlook like that do
Dialogue: 0,0:05:59.00,0:06:00.00,Default,,0000,0000,0000,,this chemistry.
Dialogue: 0,0:06:00.00,0:06:03.00,Default,,0000,0000,0000,,And this was sort of a rough\Nmodel of what they look like,
Dialogue: 0,0:06:03.00,0:06:07.00,Default,,0000,0000,0000,,and they thought it had iron\Nand sulfur and then a nickel in
Dialogue: 0,0:06:07.00,0:06:10.00,Default,,0000,0000,0000,,some geometry, but they had no\Nidea sort of where the nickel
Dialogue: 0,0:06:10.00,0:06:12.00,Default,,0000,0000,0000,,was and how it was coordinated.
Dialogue: 0,0:06:12.00,0:06:15.00,Default,,0000,0000,0000,,And so before there was any\Nkind of three dimensional
Dialogue: 0,0:06:15.00,0:06:18.00,Default,,0000,0000,0000,,information, they used\Nspectroscopy, and they
Dialogue: 0,0:06:18.00,0:06:21.00,Default,,0000,0000,0000,,considered whether it was\Nparamagnetic or diamagnetic to
Dialogue: 0,0:06:21.00,0:06:24.00,Default,,0000,0000,0000,,get a sense of what the\Ngeometry around the metal was.
Dialogue: 0,0:06:24.00,0:06:26.00,Default,,0000,0000,0000,,So we're going to talk about\Ndifferent coordination
Dialogue: 0,0:06:26.00,0:06:30.00,Default,,0000,0000,0000,,geometries and how many\Nunpaired or paired electrons
Dialogue: 0,0:06:30.00,0:06:33.00,Default,,0000,0000,0000,,you would expect, depending\Non those geometries today.
Dialogue: 0,0:06:33.00,0:06:38.00,Default,,0000,0000,0000,,And so, crystal field theory,\Nagain, can help you help
Dialogue: 0,0:06:38.00,0:06:42.00,Default,,0000,0000,0000,,explain/rationalize the\Nproperties of these transition
Dialogue: 0,0:06:42.00,0:06:46.00,Default,,0000,0000,0000,,metal complexes or\Ncoordination complexes.
Dialogue: 0,0:06:46.00,0:06:50.00,Default,,0000,0000,0000,,So, to help us think about\Ngeometry, I always find
Dialogue: 0,0:06:50.00,0:06:54.00,Default,,0000,0000,0000,,for myself that it's\Nhelpful to have models.
Dialogue: 0,0:06:54.00,0:07:01.00,Default,,0000,0000,0000,,So not everyone can have such\Nlarge models as these, but you
Dialogue: 0,0:07:01.00,0:07:06.00,Default,,0000,0000,0000,,can all have your own little\Nmodels of these geometries.
Dialogue: 0,0:07:06.00,0:07:12.00,Default,,0000,0000,0000,,So, what we have available to\Nyou are some mini marshmallows,
Dialogue: 0,0:07:12.00,0:07:15.00,Default,,0000,0000,0000,,which, of course, as we all\Nknow, are representative of d
Dialogue: 0,0:07:15.00,0:07:20.00,Default,,0000,0000,0000,,orbitals, and jelly beans,\Nwhich we all know are useful
Dialogue: 0,0:07:20.00,0:07:22.00,Default,,0000,0000,0000,,for making coordination\Ncomplexes.
Dialogue: 0,0:07:22.00,0:07:27.00,Default,,0000,0000,0000,,So, what you can do with your\Nmini marshmallows is you can
Dialogue: 0,0:07:27.00,0:07:30.00,Default,,0000,0000,0000,,put together to make\Nyour different sets.
Dialogue: 0,0:07:30.00,0:07:37.00,Default,,0000,0000,0000,,And so, over here we have --\Noh, actually it says gum drops
Dialogue: 0,0:07:37.00,0:07:39.00,Default,,0000,0000,0000,,-- you don't have gum drops\Nthis year, I changed up here, I
Dialogue: 0,0:07:39.00,0:07:41.00,Default,,0000,0000,0000,,forgot to change it down here.
Dialogue: 0,0:07:41.00,0:07:42.00,Default,,0000,0000,0000,,We have mini marshmallows.
Dialogue: 0,0:07:42.00,0:07:47.00,Default,,0000,0000,0000,,Dr. Taylor went out and tried\Nto purchase enough gum drops to
Dialogue: 0,0:07:47.00,0:07:50.00,Default,,0000,0000,0000,,do this experiment, and\Ndiscovered that Cambridge only
Dialogue: 0,0:07:50.00,0:07:55.00,Default,,0000,0000,0000,,had 300 gum drops, so we have\Nmini marshmallows
Dialogue: 0,0:07:55.00,0:07:56.00,Default,,0000,0000,0000,,instead today.
Dialogue: 0,0:07:56.00,0:07:57.00,Default,,0000,0000,0000,,But this gives you the idea.
Dialogue: 0,0:07:57.00,0:08:02.00,Default,,0000,0000,0000,,You can take one toothpick and\Nyou can make d z squared,
Dialogue: 0,0:08:02.00,0:08:06.00,Default,,0000,0000,0000,,putting on your orbitals, you\Nhave your donut in the middle,
Dialogue: 0,0:08:06.00,0:08:09.00,Default,,0000,0000,0000,,and then your two lobes,\Nwhich run along the z-axis.
Dialogue: 0,0:08:09.00,0:08:16.00,Default,,0000,0000,0000,,And then for your other sets of\Norbitals, you can take these
Dialogue: 0,0:08:16.00,0:08:23.00,Default,,0000,0000,0000,,two toothpicks and put on these\Nsets of mini marshmallows, and
Dialogue: 0,0:08:23.00,0:08:27.00,Default,,0000,0000,0000,,handily, you can just have one\Nfor all of the other d
Dialogue: 0,0:08:27.00,0:08:30.00,Default,,0000,0000,0000,,orbitals, because depending on\Nhow you hold it, it can
Dialogue: 0,0:08:30.00,0:08:35.00,Default,,0000,0000,0000,,represent all of the other d\Norbitals just very well.
Dialogue: 0,0:08:35.00,0:08:37.00,Default,,0000,0000,0000,,So, you can just have one of\Nthese for all the others
Dialogue: 0,0:08:37.00,0:08:40.00,Default,,0000,0000,0000,,and then your d z squared.
Dialogue: 0,0:08:40.00,0:08:44.00,Default,,0000,0000,0000,,So what we're going to do when\Nwe have our orbitals set up,
Dialogue: 0,0:08:44.00,0:08:49.00,Default,,0000,0000,0000,,then we can think about how\Nligands in particular
Dialogue: 0,0:08:49.00,0:08:53.00,Default,,0000,0000,0000,,positions, in particular\Ngeometries would clash with our
Dialogue: 0,0:08:53.00,0:08:55.00,Default,,0000,0000,0000,,orbitals -- where there'd be\Nbig repulsions or
Dialogue: 0,0:08:55.00,0:08:59.00,Default,,0000,0000,0000,,small repulsions.
Dialogue: 0,0:08:59.00,0:09:03.00,Default,,0000,0000,0000,,So, any other people missing\Ntheir jelly beans or
Dialogue: 0,0:09:03.00,0:09:05.00,Default,,0000,0000,0000,,their marshmallows?
Dialogue: 0,0:09:05.00,0:09:34.00,Default,,0000,0000,0000,,Please, raise your\Nhand, we have extras.
Dialogue: 0,0:09:34.00,0:09:36.00,Default,,0000,0000,0000,,So, those of you who have\Nthem, go ahead and start
Dialogue: 0,0:09:36.00,0:10:08.00,Default,,0000,0000,0000,,making your d orbitals.
Dialogue: 0,0:10:08.00,0:10:54.00,Default,,0000,0000,0000,,All right, so if you're\Nfinished with your two d
Dialogue: 0,0:10:54.00,0:11:01.00,Default,,0000,0000,0000,,orbitals, you can start making\Nan octahedral complex.
Dialogue: 0,0:11:01.00,0:11:05.00,Default,,0000,0000,0000,,So in your geometries set,\Nyou'll have a big gum which can
Dialogue: 0,0:11:05.00,0:11:11.00,Default,,0000,0000,0000,,be your center metal -- you'll\Nhave a big jelly bean -- sorry,
Dialogue: 0,0:11:11.00,0:11:14.00,Default,,0000,0000,0000,,big jelly beans and small jelly\Nbeans are our ligands, or our
Dialogue: 0,0:11:14.00,0:11:18.00,Default,,0000,0000,0000,,negative point charges, and\Nyou can set up and make an
Dialogue: 0,0:11:18.00,0:13:05.00,Default,,0000,0000,0000,,octahedral geometry here.
Dialogue: 0,0:13:05.00,0:13:10.00,Default,,0000,0000,0000,,OK, so as you're finishing this\Nup, I'm going to review what we
Dialogue: 0,0:13:10.00,0:13:13.00,Default,,0000,0000,0000,,talked about before the exam --\Nso this isn't in today's
Dialogue: 0,0:13:13.00,0:13:15.00,Default,,0000,0000,0000,,lecture handouts, it was in\Nlast time, which we
Dialogue: 0,0:13:15.00,0:13:17.00,Default,,0000,0000,0000,,already went over.
Dialogue: 0,0:13:17.00,0:13:20.00,Default,,0000,0000,0000,,But sometimes I've discovered\Nthat when there's an exam in
Dialogue: 0,0:13:20.00,0:13:23.00,Default,,0000,0000,0000,,the middle, there needs to be a\Nbit of a refresher, it's hard
Dialogue: 0,0:13:23.00,0:13:28.00,Default,,0000,0000,0000,,to remember what happened\Nbefore the exam, and you
Dialogue: 0,0:13:28.00,0:13:31.00,Default,,0000,0000,0000,,have your models to\Nthink about this.
Dialogue: 0,0:13:31.00,0:13:34.00,Default,,0000,0000,0000,,So, before the exam, we had\Ntalked about the octahedral
Dialogue: 0,0:13:34.00,0:13:38.00,Default,,0000,0000,0000,,case, and how compared to a\Nspherical situation where the
Dialogue: 0,0:13:38.00,0:13:41.00,Default,,0000,0000,0000,,ligands are everywhere\Ndistributed around the metals
Dialogue: 0,0:13:41.00,0:13:45.00,Default,,0000,0000,0000,,where all d orbitals would be\Naffected/repulsed by the
Dialogue: 0,0:13:45.00,0:13:50.00,Default,,0000,0000,0000,,ligands in a symmetric fashion\Nequally, when you have them put
Dialogue: 0,0:13:50.00,0:13:54.00,Default,,0000,0000,0000,,as particular positions in\Ngeometry, then they're going to
Dialogue: 0,0:13:54.00,0:13:57.00,Default,,0000,0000,0000,,affect the different d\Norbitals differently.
Dialogue: 0,0:13:57.00,0:14:00.00,Default,,0000,0000,0000,,And so, if you have your d z\Nsquared made, and you have your
Dialogue: 0,0:14:00.00,0:14:04.00,Default,,0000,0000,0000,,octahedral made, you can sort\Nof hold these up and realize
Dialogue: 0,0:14:04.00,0:14:09.00,Default,,0000,0000,0000,,that you would have repulsion\Nfrom your ligands along the
Dialogue: 0,0:14:09.00,0:14:14.00,Default,,0000,0000,0000,,z-axis directly toward your\Norbitals from d z squared.
Dialogue: 0,0:14:14.00,0:14:16.00,Default,,0000,0000,0000,,So that would be\Nhighly repulsive.
Dialogue: 0,0:14:16.00,0:14:20.00,Default,,0000,0000,0000,,The ligands are along the\Nz-axis, the d orbitals are
Dialogue: 0,0:14:20.00,0:14:23.00,Default,,0000,0000,0000,,along the z-axis, so the\Nligands, the negative point
Dialogue: 0,0:14:23.00,0:14:25.00,Default,,0000,0000,0000,,charge ligands are going\Nto be pointing right
Dialogue: 0,0:14:25.00,0:14:27.00,Default,,0000,0000,0000,,toward your orbitals.
Dialogue: 0,0:14:27.00,0:14:34.00,Default,,0000,0000,0000,,And if you hold up this as a d\Nx squared y squared orbital
Dialogue: 0,0:14:34.00,0:14:38.00,Default,,0000,0000,0000,,where the orbitals are right\Nalong the x-axis and right
Dialogue: 0,0:14:38.00,0:14:41.00,Default,,0000,0000,0000,,along the y-axis and you hold\Nthat up, remember, your ligands
Dialogue: 0,0:14:41.00,0:14:45.00,Default,,0000,0000,0000,,are right along the x-axis\Nand right along the y-axis.
Dialogue: 0,0:14:45.00,0:14:49.00,Default,,0000,0000,0000,,So, you should also have\Nsignificant repulsion for d x
Dialogue: 0,0:14:49.00,0:14:53.00,Default,,0000,0000,0000,,squared minus y squared, and\Noctahedrally oriented ligands.
Dialogue: 0,0:14:53.00,0:15:01.00,Default,,0000,0000,0000,,In contrast, the ligands set\Nthat are 45 degrees off-axis,
Dialogue: 0,0:15:01.00,0:15:08.00,Default,,0000,0000,0000,,so d y z, d x z, and d x y,\Nthey're all 45 degrees off.
Dialogue: 0,0:15:08.00,0:15:11.00,Default,,0000,0000,0000,,Your ligands are along the\Naxis, but your orbitals
Dialogue: 0,0:15:11.00,0:15:14.00,Default,,0000,0000,0000,,are 45 degrees off-axis.
Dialogue: 0,0:15:14.00,0:15:16.00,Default,,0000,0000,0000,,So if you look at that\Ntogether, you'll see that
Dialogue: 0,0:15:16.00,0:15:19.00,Default,,0000,0000,0000,,whichever one you look at, the\Nligands are not going to be
Dialogue: 0,0:15:19.00,0:15:22.00,Default,,0000,0000,0000,,pointing directly toward\Nthose d orbitals.
Dialogue: 0,0:15:22.00,0:15:24.00,Default,,0000,0000,0000,,The orbitals are off-axis,\Nligands are on-axis.
Dialogue: 0,0:15:24.00,0:15:29.00,Default,,0000,0000,0000,,So there will be much\Nsmaller repulsions there.
Dialogue: 0,0:15:29.00,0:15:37.00,Default,,0000,0000,0000,,And that we talked about the\Nfact that for d x squared minus
Dialogue: 0,0:15:37.00,0:15:40.00,Default,,0000,0000,0000,,y squared and d z squared,\Nthey're both have experienced
Dialogue: 0,0:15:40.00,0:15:44.00,Default,,0000,0000,0000,,large repulsions, they're both\Ndegenerate in energy, they go
Dialogue: 0,0:15:44.00,0:15:48.00,Default,,0000,0000,0000,,up in energy, whereas these\Nthree d orbitals, smaller
Dialogue: 0,0:15:48.00,0:15:52.00,Default,,0000,0000,0000,,repulsion, and they're also\Ndegenerate with respect to each
Dialogue: 0,0:15:52.00,0:15:55.00,Default,,0000,0000,0000,,other, and they're stabilized\Ncompared to these guys up here.
Dialogue: 0,0:15:55.00,0:15:58.00,Default,,0000,0000,0000,,So you can try to hold those up\Nand convince yourself that
Dialogue: 0,0:15:58.00,0:16:01.00,Default,,0000,0000,0000,,that's true for the\Noctahedral case.
Dialogue: 0,0:16:01.00,0:16:04.00,Default,,0000,0000,0000,,So, that's what we talked about\Nlast time, and now we want to
Dialogue: 0,0:16:04.00,0:16:08.00,Default,,0000,0000,0000,,-- oh, and I'll just remind you\Nwe looked at these splitting
Dialogue: 0,0:16:08.00,0:16:09.00,Default,,0000,0000,0000,,diagrams as well.
Dialogue: 0,0:16:09.00,0:16:13.00,Default,,0000,0000,0000,,We looked at the average energy\Nof the d orbitals -- d z
Dialogue: 0,0:16:13.00,0:16:17.00,Default,,0000,0000,0000,,squared and d x squared minus\Ny squared go up in energy,
Dialogue: 0,0:16:17.00,0:16:24.00,Default,,0000,0000,0000,,and then the other three d\Norbitals go down in energy.
Dialogue: 0,0:16:24.00,0:16:27.00,Default,,0000,0000,0000,,So now we want to consider\Nwhat happens with
Dialogue: 0,0:16:27.00,0:16:31.00,Default,,0000,0000,0000,,different geometries.
Dialogue: 0,0:16:31.00,0:16:35.00,Default,,0000,0000,0000,,So now you can turn your\Noctahedral case into a
Dialogue: 0,0:16:35.00,0:16:42.00,Default,,0000,0000,0000,,square planar case, and\Nhow am I going to do that?
Dialogue: 0,0:16:42.00,0:16:45.00,Default,,0000,0000,0000,,Yeah, so we can just take off\Nthe top and the bottom and we
Dialogue: 0,0:16:45.00,0:16:51.00,Default,,0000,0000,0000,,have our nice square planar\Ncase, and try to make a
Dialogue: 0,0:16:51.00,0:16:57.00,Default,,0000,0000,0000,,tetrahedral complex as well.
Dialogue: 0,0:16:57.00,0:16:59.00,Default,,0000,0000,0000,,And here's an example\Nof a tetrahedral one.
Dialogue: 0,0:16:59.00,0:17:02.00,Default,,0000,0000,0000,,Again, you can take a jelly\Nbean in the middle, and big
Dialogue: 0,0:17:02.00,0:17:05.00,Default,,0000,0000,0000,,jelly bean, and then the\Nsmaller ones on the outside.
Dialogue: 0,0:17:05.00,0:17:08.00,Default,,0000,0000,0000,,So what angles am I going for\Nhere in the tetrahedral case?
Dialogue: 0,0:17:08.00,0:17:10.00,Default,,0000,0000,0000,,109 .
Dialogue: 0,0:17:10.00,0:17:11.00,Default,,0000,0000,0000,,5.
Dialogue: 0,0:17:11.00,0:17:15.00,Default,,0000,0000,0000,,So you can go ahead and make\Nyour tetrahedral complex,
Dialogue: 0,0:17:15.00,0:17:17.00,Default,,0000,0000,0000,,and don't worry so\Nmuch about the 0 .
Dialogue: 0,0:17:17.00,0:18:36.00,Default,,0000,0000,0000,,5, but we'll see if people can\Ndo a good job with the 109.
Dialogue: 0,0:18:36.00,0:18:40.00,Default,,0000,0000,0000,,OK, how are your tetrahedral\Ncomplexes coming?
Dialogue: 0,0:18:40.00,0:18:46.00,Default,,0000,0000,0000,,Do they look like this sort of?
Dialogue: 0,0:18:46.00,0:18:49.00,Default,,0000,0000,0000,,So let me define for you how\Nwe're going to consider
Dialogue: 0,0:18:49.00,0:18:52.00,Default,,0000,0000,0000,,the tetrahedral case.
Dialogue: 0,0:18:52.00,0:18:56.00,Default,,0000,0000,0000,,So, in the tetrahedral case,\Nwe're going to have the x-axis
Dialogue: 0,0:18:56.00,0:19:00.00,Default,,0000,0000,0000,,comes out of the plane, the\Ny-axis is this way, z-axis
Dialogue: 0,0:19:00.00,0:19:02.00,Default,,0000,0000,0000,,again, up and down.
Dialogue: 0,0:19:02.00,0:19:05.00,Default,,0000,0000,0000,,We're going to have one ligand\Ncoming out here, another going
Dialogue: 0,0:19:05.00,0:19:07.00,Default,,0000,0000,0000,,back, and then these two\Nare pretty much in the
Dialogue: 0,0:19:07.00,0:19:09.00,Default,,0000,0000,0000,,plane of the screen.
Dialogue: 0,0:19:09.00,0:19:12.00,Default,,0000,0000,0000,,So this is sort of how I'm\Nholding the tetrahedral complex
Dialogue: 0,0:19:12.00,0:19:18.00,Default,,0000,0000,0000,,with respect to the x, z,\Nand y coordinate system.
Dialogue: 0,0:19:18.00,0:19:21.00,Default,,0000,0000,0000,,So, there is a splitting,\Nenergy splitting, associated
Dialogue: 0,0:19:21.00,0:19:25.00,Default,,0000,0000,0000,,with tetrahedral, and it's\Ngoing to be smaller than
Dialogue: 0,0:19:25.00,0:19:29.00,Default,,0000,0000,0000,,octahedral because none of\Nthese ligands will be pointing
Dialogue: 0,0:19:29.00,0:19:31.00,Default,,0000,0000,0000,,directly toward the orbitals.
Dialogue: 0,0:19:31.00,0:19:36.00,Default,,0000,0000,0000,,But let's consider which\Norbitals are going to be most
Dialogue: 0,0:19:36.00,0:19:42.00,Default,,0000,0000,0000,,affected by a tetrahedral case.
Dialogue: 0,0:19:42.00,0:19:48.00,Default,,0000,0000,0000,,So, let's consider d z squared.
Dialogue: 0,0:19:48.00,0:19:49.00,Default,,0000,0000,0000,,What do you think?
Dialogue: 0,0:19:49.00,0:19:52.00,Default,,0000,0000,0000,,Is that going to be\Nparticularly -- are the ligands
Dialogue: 0,0:19:52.00,0:19:55.00,Default,,0000,0000,0000,,pointing toward d z squared?
Dialogue: 0,0:19:55.00,0:19:57.00,Default,,0000,0000,0000,,No.
Dialogue: 0,0:19:57.00,0:20:01.00,Default,,0000,0000,0000,,And d x squared minus y\Nsquared, we can think of,
Dialogue: 0,0:20:01.00,0:20:04.00,Default,,0000,0000,0000,,what about that one?
Dialogue: 0,0:20:04.00,0:20:06.00,Default,,0000,0000,0000,,No, not really.
Dialogue: 0,0:20:06.00,0:20:12.00,Default,,0000,0000,0000,,What about d x y,\Nd y z, and d x y?
Dialogue: 0,0:20:12.00,0:20:17.00,Default,,0000,0000,0000,,Moreso.
Dialogue: 0,0:20:17.00,0:20:20.00,Default,,0000,0000,0000,,So, if you try holding up your\Ntetrahedral in our coordinate
Dialogue: 0,0:20:20.00,0:20:25.00,Default,,0000,0000,0000,,system, and then hold your d\Norbitals 45 degrees off-axis,
Dialogue: 0,0:20:25.00,0:20:28.00,Default,,0000,0000,0000,,it's not perfect, they're not\Npointing directly toward them,
Dialogue: 0,0:20:28.00,0:20:31.00,Default,,0000,0000,0000,,but it's a little closer than\Nfor the d orbitals that
Dialogue: 0,0:20:31.00,0:20:36.00,Default,,0000,0000,0000,,are directly on-axis.
Dialogue: 0,0:20:36.00,0:20:41.00,Default,,0000,0000,0000,,So, if we look at this, we see\Nthat the orbitals are going to
Dialogue: 0,0:20:41.00,0:20:46.00,Default,,0000,0000,0000,,be split in the exact opposite\Nway of the octahedral system.
Dialogue: 0,0:20:46.00,0:20:50.00,Default,,0000,0000,0000,,In the octahedral system, the\Nligands are on-axis, so the
Dialogue: 0,0:20:50.00,0:20:53.00,Default,,0000,0000,0000,,orbitals that are on-axis, d x\Nsquared minus y squared and d
Dialogue: 0,0:20:53.00,0:20:56.00,Default,,0000,0000,0000,,z squared are going to\Nbe the most affected.
Dialogue: 0,0:20:56.00,0:20:59.00,Default,,0000,0000,0000,,But with tetrahedral, the\Nligands are off-axis, so the
Dialogue: 0,0:20:59.00,0:21:02.00,Default,,0000,0000,0000,,d orbitals that are also\Noff-axis are going to
Dialogue: 0,0:21:02.00,0:21:03.00,Default,,0000,0000,0000,,be the most affected.
Dialogue: 0,0:21:03.00,0:21:06.00,Default,,0000,0000,0000,,But they're not going to be as\Ndramatically affected, so the
Dialogue: 0,0:21:06.00,0:21:09.00,Default,,0000,0000,0000,,splitting is actually\Nsmaller in this case.
Dialogue: 0,0:21:09.00,0:21:13.00,Default,,0000,0000,0000,,So here, with tetrahedral,\Nyou have the opposite of
Dialogue: 0,0:21:13.00,0:21:16.00,Default,,0000,0000,0000,,the octahedral system.
Dialogue: 0,0:21:16.00,0:21:19.00,Default,,0000,0000,0000,,And you can keep these and\Ntry to convince yourself
Dialogue: 0,0:21:19.00,0:21:25.00,Default,,0000,0000,0000,,of that later if you have\Ntrouble visualizing it.
Dialogue: 0,0:21:25.00,0:21:29.00,Default,,0000,0000,0000,,So, you'll have more repulsion\Nbetween the ligands as negative
Dialogue: 0,0:21:29.00,0:21:32.00,Default,,0000,0000,0000,,point charges, and the d\Norbitals that are 45 degrees
Dialogue: 0,0:21:32.00,0:21:36.00,Default,,0000,0000,0000,,off-axis than you do with\Nthe two d orbitals
Dialogue: 0,0:21:36.00,0:21:39.00,Default,,0000,0000,0000,,that are on-axis.
Dialogue: 0,0:21:39.00,0:21:44.00,Default,,0000,0000,0000,,So here, d x squared minus y\Nsquared and d z squared have
Dialogue: 0,0:21:44.00,0:21:47.00,Default,,0000,0000,0000,,the same energy with respect to\Neach other, they're degenerate.
Dialogue: 0,0:21:47.00,0:21:54.00,Default,,0000,0000,0000,,And we have our d y z, x z,\Nand x y have the same energy
Dialogue: 0,0:21:54.00,0:21:58.00,Default,,0000,0000,0000,,with respect to each other,\Nthey are also degenerate.
Dialogue: 0,0:21:58.00,0:22:01.00,Default,,0000,0000,0000,,So it's the same sets that\Nare degenerate as with
Dialogue: 0,0:22:01.00,0:22:08.00,Default,,0000,0000,0000,,octahedral, but they're\Nall affected differently.
Dialogue: 0,0:22:08.00,0:22:13.00,Default,,0000,0000,0000,,So now let's look at the energy\Ndiagrams and compare the
Dialogue: 0,0:22:13.00,0:22:17.00,Default,,0000,0000,0000,,octahedral system with\Nthe tetrahedral system.
Dialogue: 0,0:22:17.00,0:22:20.00,Default,,0000,0000,0000,,Remember an octahedral, we\Nhad the two orbitals going
Dialogue: 0,0:22:20.00,0:22:22.00,Default,,0000,0000,0000,,up and three going down.
Dialogue: 0,0:22:22.00,0:22:25.00,Default,,0000,0000,0000,,The splitting, the energy\Ndifference between
Dialogue: 0,0:22:25.00,0:22:26.00,Default,,0000,0000,0000,,them was abbreviated.
Dialogue: 0,0:22:26.00,0:22:29.00,Default,,0000,0000,0000,,The octahedral crystal field\Nsplitting energy, with a
Dialogue: 0,0:22:29.00,0:22:31.00,Default,,0000,0000,0000,,little o for octahedral.
Dialogue: 0,0:22:31.00,0:22:35.00,Default,,0000,0000,0000,,We now have a t for\Ntetrahedral, so we have
Dialogue: 0,0:22:35.00,0:22:37.00,Default,,0000,0000,0000,,a different name.
Dialogue: 0,0:22:37.00,0:22:41.00,Default,,0000,0000,0000,,And so here is now\Nour tetrahedral set.
Dialogue: 0,0:22:41.00,0:22:44.00,Default,,0000,0000,0000,,You notice it's the opposite of\Noctahedral, so the orbitals
Dialogue: 0,0:22:44.00,0:22:49.00,Default,,0000,0000,0000,,that were most destabilized in\Nthe octahedral case are now
Dialogue: 0,0:22:49.00,0:22:54.00,Default,,0000,0000,0000,,more stabilized down here, so\Nwe've moved down in energy.
Dialogue: 0,0:22:54.00,0:22:58.00,Default,,0000,0000,0000,,And the orbitals that are\Noff-axis, 45 degrees off-axis,
Dialogue: 0,0:22:58.00,0:23:02.00,Default,,0000,0000,0000,,which were stabilized in the\Noctahedral system, because none
Dialogue: 0,0:23:02.00,0:23:05.00,Default,,0000,0000,0000,,of ligands were pointing right\Ntoward them, now those ligands
Dialogue: 0,0:23:05.00,0:23:09.00,Default,,0000,0000,0000,,are a bit closer so they jump\Nup in energy, and so we have
Dialogue: 0,0:23:09.00,0:23:15.00,Default,,0000,0000,0000,,this swap between the two.
Dialogue: 0,0:23:15.00,0:23:18.00,Default,,0000,0000,0000,,So, we have some new\Nlabels as well.
Dialogue: 0,0:23:18.00,0:23:24.00,Default,,0000,0000,0000,,So, we had e g up here as an\Nabbreviation for these sets
Dialogue: 0,0:23:24.00,0:23:27.00,Default,,0000,0000,0000,,of orbitals, and now that's\Njust referred to as e.
Dialogue: 0,0:23:27.00,0:23:32.00,Default,,0000,0000,0000,,Notice the book in one place\Nhas an e 2, but uses e in all
Dialogue: 0,0:23:32.00,0:23:35.00,Default,,0000,0000,0000,,the other places, so just\Nuse e, the e 2 was a
Dialogue: 0,0:23:35.00,0:23:36.00,Default,,0000,0000,0000,,mistake in the book.
Dialogue: 0,0:23:36.00,0:23:42.00,Default,,0000,0000,0000,,And then we have t 2 g\Nbecomes t 2 up here.
Dialogue: 0,0:23:42.00,0:23:45.00,Default,,0000,0000,0000,,So we have this slightly\Ndifferent nomenclature and we
Dialogue: 0,0:23:45.00,0:23:49.00,Default,,0000,0000,0000,,have this flip in direction.
Dialogue: 0,0:23:49.00,0:23:53.00,Default,,0000,0000,0000,,So, the other thing that is\Nimportant to emphasize is that
Dialogue: 0,0:23:53.00,0:23:58.00,Default,,0000,0000,0000,,the tetrahedral splitting\Nenergy is smaller, because none
Dialogue: 0,0:23:58.00,0:24:00.00,Default,,0000,0000,0000,,of those ligands are pointing\Ndirectly toward any
Dialogue: 0,0:24:00.00,0:24:01.00,Default,,0000,0000,0000,,of the d orbitals.
Dialogue: 0,0:24:01.00,0:24:05.00,Default,,0000,0000,0000,,So here there is a much larger\Ndifference, here there is a
Dialogue: 0,0:24:05.00,0:24:09.00,Default,,0000,0000,0000,,smaller difference, so that's\Nwhy it's written much closer
Dialogue: 0,0:24:09.00,0:24:14.00,Default,,0000,0000,0000,,together, so that's smaller.
Dialogue: 0,0:24:14.00,0:24:19.00,Default,,0000,0000,0000,,And because of that, many\Ntetrahedral complexes are high
Dialogue: 0,0:24:19.00,0:24:21.00,Default,,0000,0000,0000,,spin, and in this course, you\Ncan assume that they're
Dialogue: 0,0:24:21.00,0:24:23.00,Default,,0000,0000,0000,,all high spin.
Dialogue: 0,0:24:23.00,0:24:25.00,Default,,0000,0000,0000,,So that means there's a weak\Nfield, there's not a big
Dialogue: 0,0:24:25.00,0:24:31.00,Default,,0000,0000,0000,,energy difference between\Nthose orbital sets.
Dialogue: 0,0:24:31.00,0:24:35.00,Default,,0000,0000,0000,,And again, we're going to --\Nsince we're going to consider
Dialogue: 0,0:24:35.00,0:24:38.00,Default,,0000,0000,0000,,how much they go up and down\Nin energy, the overall
Dialogue: 0,0:24:38.00,0:24:40.00,Default,,0000,0000,0000,,energy is maintained.
Dialogue: 0,0:24:40.00,0:24:45.00,Default,,0000,0000,0000,,So here we had two orbitals\Ngoing up by 3/5, three
Dialogue: 0,0:24:45.00,0:24:47.00,Default,,0000,0000,0000,,orbitals going down by 2/5.
Dialogue: 0,0:24:47.00,0:24:50.00,Default,,0000,0000,0000,,So here, we have three orbitals\Ngoing up, so they'll go up in
Dialogue: 0,0:24:50.00,0:24:54.00,Default,,0000,0000,0000,,energy by 2/5, two orbitals go\Ndown, so they'll be going
Dialogue: 0,0:24:54.00,0:24:57.00,Default,,0000,0000,0000,,down in energy by 3/5.
Dialogue: 0,0:24:57.00,0:25:01.00,Default,,0000,0000,0000,,So again, it's the opposite\Nof the octahedral system.
Dialogue: 0,0:25:01.00,0:25:03.00,Default,,0000,0000,0000,,It's opposite pretty much in\Nevery way except that the
Dialogue: 0,0:25:03.00,0:25:06.00,Default,,0000,0000,0000,,splitting energy is much\Nsmaller, it's not as large
Dialogue: 0,0:25:06.00,0:25:11.00,Default,,0000,0000,0000,,for the tetrahedral complex.
Dialogue: 0,0:25:11.00,0:25:15.00,Default,,0000,0000,0000,,All right, so let's look at an\Nexample, and we're going to
Dialogue: 0,0:25:15.00,0:25:20.00,Default,,0000,0000,0000,,consider a chromium, and like\Nwe did before, we have to first
Dialogue: 0,0:25:20.00,0:25:26.00,Default,,0000,0000,0000,,figure out the d count, so\Nwe have chromium plus 3.
Dialogue: 0,0:25:26.00,0:25:32.00,Default,,0000,0000,0000,,So what is our d count here?
Dialogue: 0,0:25:32.00,0:25:36.00,Default,,0000,0000,0000,,You know where chromium is,\Nwhat its group number --
Dialogue: 0,0:25:36.00,0:25:42.00,Default,,0000,0000,0000,,here is a periodic table.
Dialogue: 0,0:25:42.00,0:25:45.00,Default,,0000,0000,0000,,So what is the d count?
Dialogue: 0,0:25:45.00,0:25:46.00,Default,,0000,0000,0000,,3.
Dialogue: 0,0:25:46.00,0:25:53.00,Default,,0000,0000,0000,,So we have 6 minus 3,\N3 -- a d 3 system.
Dialogue: 0,0:25:53.00,0:25:58.00,Default,,0000,0000,0000,,And now, why don't you tell me\Nhow you would fill in those
Dialogue: 0,0:25:58.00,0:26:02.00,Default,,0000,0000,0000,,three electrons in a\Ntetrahedral case.
Dialogue: 0,0:26:02.00,0:26:56.00,Default,,0000,0000,0000,,Have a clicker question there.
Dialogue: 0,0:26:56.00,0:27:00.00,Default,,0000,0000,0000,,So, notice that in addition to\Nhaving electron configurations
Dialogue: 0,0:27:00.00,0:27:02.00,Default,,0000,0000,0000,,that are different, the d\Norbitals are labelled
Dialogue: 0,0:27:02.00,0:27:29.00,Default,,0000,0000,0000,,differently.
Dialogue: 0,0:27:29.00,0:27:44.00,Default,,0000,0000,0000,,OK, 10 more seconds.
Dialogue: 0,0:27:44.00,0:27:47.00,Default,,0000,0000,0000,,OK, very good, 80%.
Dialogue: 0,0:27:47.00,0:27:49.00,Default,,0000,0000,0000,,So, let's take a look at that.
Dialogue: 0,0:27:49.00,0:27:53.00,Default,,0000,0000,0000,,So down here, we're going to\Nhave then our d x squared minus
Dialogue: 0,0:27:53.00,0:27:58.00,Default,,0000,0000,0000,,y squared, d z squared orbitals\Nup in the top, we have
Dialogue: 0,0:27:58.00,0:28:05.00,Default,,0000,0000,0000,,x y and x z and y z.
Dialogue: 0,0:28:05.00,0:28:10.00,Default,,0000,0000,0000,,Again, the orbitals that are\Non-axis are repelled a little
Dialogue: 0,0:28:10.00,0:28:14.00,Default,,0000,0000,0000,,less than the orbitals that are\Noff-axis in a tetrahedral case.
Dialogue: 0,0:28:14.00,0:28:18.00,Default,,0000,0000,0000,,And then we put in our\Nelectrons, we start down here.
Dialogue: 0,0:28:18.00,0:28:21.00,Default,,0000,0000,0000,,And then one of the questions\Nis do we keep down here and
Dialogue: 0,0:28:21.00,0:28:26.00,Default,,0000,0000,0000,,pair up or go up here, and the\Nanswer is that you
Dialogue: 0,0:28:26.00,0:28:27.00,Default,,0000,0000,0000,,would go up here.
Dialogue: 0,0:28:27.00,0:28:31.00,Default,,0000,0000,0000,,Does someone want to tell me\Nwhy they think that's true?
Dialogue: 0,0:28:31.00,0:28:31.00,Default,,0000,0000,0000,,Yeah.
Dialogue: 0,0:28:31.00,0:28:33.00,Default,,0000,0000,0000,,STUDENT: [INAUDIBLE]
Dialogue: 0,0:28:33.00,0:28:36.00,Default,,0000,0000,0000,,PROFESSOR: Right, because it\Nhas a smaller splitting energy.
Dialogue: 0,0:28:36.00,0:28:38.00,Default,,0000,0000,0000,,So, the way that we were\Ndeciding before with the weak
Dialogue: 0,0:28:38.00,0:28:41.00,Default,,0000,0000,0000,,field and the strong field, if\Nit's a weak field, it doesn't
Dialogue: 0,0:28:41.00,0:28:43.00,Default,,0000,0000,0000,,take much energy to\Nput it up there.
Dialogue: 0,0:28:43.00,0:28:45.00,Default,,0000,0000,0000,,So you go they don't want to\Nbe paired, there's energy
Dialogue: 0,0:28:45.00,0:28:47.00,Default,,0000,0000,0000,,associated with pairing.
Dialogue: 0,0:28:47.00,0:28:51.00,Default,,0000,0000,0000,,But if there's a really huge\Nsplitting energy, then it takes
Dialogue: 0,0:28:51.00,0:28:54.00,Default,,0000,0000,0000,,less energy to pair them up\Nbefore you go that big
Dialogue: 0,0:28:54.00,0:28:55.00,Default,,0000,0000,0000,,distance up there.
Dialogue: 0,0:28:55.00,0:28:58.00,Default,,0000,0000,0000,,But in tetrahedral cases, the\Nsplitting energy's always
Dialogue: 0,0:28:58.00,0:29:02.00,Default,,0000,0000,0000,,small, so you're just going to\Nalways fill them up singly
Dialogue: 0,0:29:02.00,0:29:05.00,Default,,0000,0000,0000,,to the fullest extent\Npossible before you pair.
Dialogue: 0,0:29:05.00,0:29:09.00,Default,,0000,0000,0000,,So this is like a weak field\Ncase for the octahedral system,
Dialogue: 0,0:29:09.00,0:29:12.00,Default,,0000,0000,0000,,and all tetrahedral complexes\Nare sort of the equivalent of
Dialogue: 0,0:29:12.00,0:29:14.00,Default,,0000,0000,0000,,the weak field, because the\Nsplitting energy is always
Dialogue: 0,0:29:14.00,0:29:18.00,Default,,0000,0000,0000,,small in an octahedral case,\Nbecause none of the ligands'
Dialogue: 0,0:29:18.00,0:29:21.00,Default,,0000,0000,0000,,negative point charges are\Nreally pointing toward any of
Dialogue: 0,0:29:21.00,0:29:25.00,Default,,0000,0000,0000,,those orbitals that much, so\Nit's not that big a difference.
Dialogue: 0,0:29:25.00,0:29:30.00,Default,,0000,0000,0000,,So, here we have this and now\Nwe can practice writing our d
Dialogue: 0,0:29:30.00,0:29:33.00,Default,,0000,0000,0000,,to the n electron\Nconfiguration.
Dialogue: 0,0:29:33.00,0:29:38.00,Default,,0000,0000,0000,,So what do I put here?
Dialogue: 0,0:29:38.00,0:29:42.00,Default,,0000,0000,0000,,What do I put first?
Dialogue: 0,0:29:42.00,0:29:46.00,Default,,0000,0000,0000,,So we put the e and then what?
Dialogue: 0,0:29:46.00,0:29:47.00,Default,,0000,0000,0000,,Yup.
Dialogue: 0,0:29:47.00,0:29:51.00,Default,,0000,0000,0000,,There are two electrons in the\Ne set of orbitals, and in the
Dialogue: 0,0:29:51.00,0:29:55.00,Default,,0000,0000,0000,,t 2 orbitals, there's one.
Dialogue: 0,0:29:55.00,0:29:59.00,Default,,0000,0000,0000,,So that is our d n\Nelectron configuration.
Dialogue: 0,0:29:59.00,0:30:03.00,Default,,0000,0000,0000,,And then we're also asked how\Nmany unpaired electrons.
Dialogue: 0,0:30:03.00,0:30:16.00,Default,,0000,0000,0000,,Unpaired electrons\Nand that is three.
Dialogue: 0,0:30:16.00,0:30:16.00,Default,,0000,0000,0000,,All right.
Dialogue: 0,0:30:16.00,0:30:21.00,Default,,0000,0000,0000,,So that's not too bad, that's\Nthe tetrahedral case.
Dialogue: 0,0:30:21.00,0:30:23.00,Default,,0000,0000,0000,,The hardest part is\Nprobably making your
Dialogue: 0,0:30:23.00,0:30:27.00,Default,,0000,0000,0000,,tetrahedral complex.
Dialogue: 0,0:30:27.00,0:30:31.00,Default,,0000,0000,0000,,Now square planar.
Dialogue: 0,0:30:31.00,0:30:34.00,Default,,0000,0000,0000,,So again, with the square\Nplanar set you have your square
Dialogue: 0,0:30:34.00,0:30:38.00,Default,,0000,0000,0000,,planar model -- we have\Na bigger one down here.
Dialogue: 0,0:30:38.00,0:30:43.00,Default,,0000,0000,0000,,And the axes is defined such\Nthat we have ligands right
Dialogue: 0,0:30:43.00,0:30:46.00,Default,,0000,0000,0000,,along x -- one coming out at\Nyou and one going back, and
Dialogue: 0,0:30:46.00,0:30:50.00,Default,,0000,0000,0000,,also ligands right\Nalong the y-axis.
Dialogue: 0,0:30:50.00,0:30:53.00,Default,,0000,0000,0000,,So as defined then, we've\Ngotten rid of our ligands
Dialogue: 0,0:30:53.00,0:30:56.00,Default,,0000,0000,0000,,along the z-axis.
Dialogue: 0,0:30:56.00,0:30:57.00,Default,,0000,0000,0000,,So, what do you predict?
Dialogue: 0,0:30:57.00,0:31:04.00,Default,,0000,0000,0000,,Which two of these will be\Nthe most destabilized now?
Dialogue: 0,0:31:04.00,0:31:06.00,Default,,0000,0000,0000,,What would be the most\Ndestabilized, what
Dialogue: 0,0:31:06.00,0:31:09.00,Default,,0000,0000,0000,,do you guess?
Dialogue: 0,0:31:09.00,0:31:13.00,Default,,0000,0000,0000,,You can hold up your\Nlittle sets here.
Dialogue: 0,0:31:13.00,0:31:15.00,Default,,0000,0000,0000,,What's the most destabilized,\Nwhat's going to go up
Dialogue: 0,0:31:15.00,0:31:19.00,Default,,0000,0000,0000,,the most in energy here?
Dialogue: 0,0:31:19.00,0:31:22.00,Default,,0000,0000,0000,,Yeah, d z squared\Nminus y squared.
Dialogue: 0,0:31:22.00,0:31:26.00,Default,,0000,0000,0000,,What do you predict might\Nbe next, in terms of
Dialogue: 0,0:31:26.00,0:31:29.00,Default,,0000,0000,0000,,most unfavorable?
Dialogue: 0,0:31:29.00,0:31:30.00,Default,,0000,0000,0000,,Yeah, the x y one.
Dialogue: 0,0:31:30.00,0:31:35.00,Default,,0000,0000,0000,,So these two now are going to\Nbe the most destabilized, with
Dialogue: 0,0:31:35.00,0:31:39.00,Default,,0000,0000,0000,,d x squared minus y squared\Nbeing a lot more destabilized
Dialogue: 0,0:31:39.00,0:31:42.00,Default,,0000,0000,0000,,than just the x y, because\Nagain, those d orbitals
Dialogue: 0,0:31:42.00,0:31:47.00,Default,,0000,0000,0000,,are on-axis and these\Nligands are on-axis.
Dialogue: 0,0:31:47.00,0:31:51.00,Default,,0000,0000,0000,,So, let's take a look\Nat all of these again.
Dialogue: 0,0:31:51.00,0:31:55.00,Default,,0000,0000,0000,,So in the octahedral case,\Nthese were degenerate.
Dialogue: 0,0:31:55.00,0:31:58.00,Default,,0000,0000,0000,,That's no longer true,\Nbecause there are no ligands
Dialogue: 0,0:31:58.00,0:32:00.00,Default,,0000,0000,0000,,along the z-axis anymore.
Dialogue: 0,0:32:00.00,0:32:03.00,Default,,0000,0000,0000,,So we took those off in going\Nfrom the octahedral to the
Dialogue: 0,0:32:03.00,0:32:07.00,Default,,0000,0000,0000,,square planar, so you have much\Nless repulsion, but with the d
Dialogue: 0,0:32:07.00,0:32:12.00,Default,,0000,0000,0000,,x squared minus y squared, you\Nstill have a lot repulsion.
Dialogue: 0,0:32:12.00,0:32:17.00,Default,,0000,0000,0000,,so then if we start building up\Nour case, and this diagram is,
Dialogue: 0,0:32:17.00,0:32:19.00,Default,,0000,0000,0000,,I think, on the next page of\Nyour handout, but I'm going to
Dialogue: 0,0:32:19.00,0:32:21.00,Default,,0000,0000,0000,,start building it\Nall up together.
Dialogue: 0,0:32:21.00,0:32:26.00,Default,,0000,0000,0000,,So now d x squared, y squared\Nis really high up, it's very
Dialogue: 0,0:32:26.00,0:32:29.00,Default,,0000,0000,0000,,much more destabilized\Nthan anybody else.
Dialogue: 0,0:32:29.00,0:32:32.00,Default,,0000,0000,0000,,D z squared, on the\Nother hand, is down.
Dialogue: 0,0:32:32.00,0:32:35.00,Default,,0000,0000,0000,,It's not -- it would be\Nstabilized compared -- it's
Dialogue: 0,0:32:35.00,0:32:40.00,Default,,0000,0000,0000,,not nearly as destabilized\Nas the other system.
Dialogue: 0,0:32:40.00,0:32:44.00,Default,,0000,0000,0000,,So then we go back\Nand look at these.
Dialogue: 0,0:32:44.00,0:32:48.00,Default,,0000,0000,0000,,You told me that d x y would\Nprobably be next, and
Dialogue: 0,0:32:48.00,0:32:50.00,Default,,0000,0000,0000,,that's a very good guess.
Dialogue: 0,0:32:50.00,0:32:53.00,Default,,0000,0000,0000,,You see you have more repulsion\Nthan in the other two, because
Dialogue: 0,0:32:53.00,0:32:56.00,Default,,0000,0000,0000,,the other orbitals have\Nsome z component in them.
Dialogue: 0,0:32:56.00,0:33:00.00,Default,,0000,0000,0000,,So you have less repulsion than\Nd x squared minus y squared,
Dialogue: 0,0:33:00.00,0:33:04.00,Default,,0000,0000,0000,,because it's 45 degrees off,\Nbut still that one is probably
Dialogue: 0,0:33:04.00,0:33:07.00,Default,,0000,0000,0000,,going to be up a little bit\Nmore in energy than
Dialogue: 0,0:33:07.00,0:33:08.00,Default,,0000,0000,0000,,the other set.
Dialogue: 0,0:33:08.00,0:33:13.00,Default,,0000,0000,0000,,These two here are stabilized\Ncompared to the others, so
Dialogue: 0,0:33:13.00,0:33:14.00,Default,,0000,0000,0000,,they're somewhere down here.
Dialogue: 0,0:33:14.00,0:33:18.00,Default,,0000,0000,0000,,Now the exact sort of\Narrangement can vary a little
Dialogue: 0,0:33:18.00,0:33:22.00,Default,,0000,0000,0000,,bit, but the important points\Nare that the d x squared minus
Dialogue: 0,0:33:22.00,0:33:26.00,Default,,0000,0000,0000,,y squared is the most\Ndestabilized, d x y would be
Dialogue: 0,0:33:26.00,0:33:31.00,Default,,0000,0000,0000,,next, and the other are\Nmuch lower in energy.
Dialogue: 0,0:33:31.00,0:33:34.00,Default,,0000,0000,0000,,And we're not going to do this\Nhow much up and down thing,
Dialogue: 0,0:33:34.00,0:33:38.00,Default,,0000,0000,0000,,like the 3/5 and the\N2/5 because it's more
Dialogue: 0,0:33:38.00,0:33:40.00,Default,,0000,0000,0000,,complicated in this case.
Dialogue: 0,0:33:40.00,0:33:43.00,Default,,0000,0000,0000,,So just the basic rationale you\Nneed to know here, not the
Dialogue: 0,0:33:43.00,0:33:52.00,Default,,0000,0000,0000,,exact energy differences\Nin this particular case.
Dialogue: 0,0:33:52.00,0:33:58.00,Default,,0000,0000,0000,,OK, so now we've thought about\Nthree different kinds of
Dialogue: 0,0:33:58.00,0:34:01.00,Default,,0000,0000,0000,,geometries -- octahedral,\Ntetrahedral, and
Dialogue: 0,0:34:01.00,0:34:02.00,Default,,0000,0000,0000,,the square planar.
Dialogue: 0,0:34:02.00,0:34:07.00,Default,,0000,0000,0000,,You should be able to\Nrationalize, for any
Dialogue: 0,0:34:07.00,0:34:10.00,Default,,0000,0000,0000,,geometry that I give\Nyou, what would be true.
Dialogue: 0,0:34:10.00,0:34:14.00,Default,,0000,0000,0000,,If I tell you the geometry and\Nhow it compares with our frame,
Dialogue: 0,0:34:14.00,0:34:19.00,Default,,0000,0000,0000,,with our axis frame of where\Nthe z-axis is, you should be
Dialogue: 0,0:34:19.00,0:34:21.00,Default,,0000,0000,0000,,able to tell me which\Norbital sets would be
Dialogue: 0,0:34:21.00,0:34:24.00,Default,,0000,0000,0000,,the most destabilized.
Dialogue: 0,0:34:24.00,0:34:28.00,Default,,0000,0000,0000,,And to give you practice,\Nwhy don't you try
Dialogue: 0,0:34:28.00,0:34:29.00,Default,,0000,0000,0000,,this one right here.
Dialogue: 0,0:34:29.00,0:34:35.00,Default,,0000,0000,0000,,So we have a square pyramidal\Ncase as drawn here with the
Dialogue: 0,0:34:35.00,0:34:40.00,Default,,0000,0000,0000,,axes labeled z, y and x,\Ncoming in and coming out.
Dialogue: 0,0:34:40.00,0:34:46.00,Default,,0000,0000,0000,,Tell me which of the following\Nstatements are true.
Dialogue: 0,0:34:46.00,0:34:51.00,Default,,0000,0000,0000,,And if you want, you can take\Nyour square planar and turn it
Dialogue: 0,0:34:51.00,0:35:54.00,Default,,0000,0000,0000,,into the geometry\Nto help you out.
Dialogue: 0,0:35:54.00,0:36:10.00,Default,,0000,0000,0000,,Let's just take\N10 more seconds.
Dialogue: 0,0:36:10.00,0:36:11.00,Default,,0000,0000,0000,,All right.
Dialogue: 0,0:36:11.00,0:36:13.00,Default,,0000,0000,0000,,That was good.
Dialogue: 0,0:36:13.00,0:36:15.00,Default,,0000,0000,0000,,People did well on\Nthat question.
Dialogue: 0,0:36:15.00,0:36:25.00,Default,,0000,0000,0000,,So, if we consider that we\Nhad the top two are correct.
Dialogue: 0,0:36:25.00,0:36:29.00,Default,,0000,0000,0000,,So, if we consider the d z\Nsquared, now we've put a ligand
Dialogue: 0,0:36:29.00,0:36:33.00,Default,,0000,0000,0000,,along z, so that is going to\Ncause that to be more
Dialogue: 0,0:36:33.00,0:36:37.00,Default,,0000,0000,0000,,destabilized for this geometry\Nrather than square planar,
Dialogue: 0,0:36:37.00,0:36:42.00,Default,,0000,0000,0000,,which doesn't have anything in\Nthe z direction. ah And then in
Dialogue: 0,0:36:42.00,0:36:47.00,Default,,0000,0000,0000,,terms, also, other orbitals\Nthat have a component along z
Dialogue: 0,0:36:47.00,0:36:52.00,Default,,0000,0000,0000,,are going to be affected a\Nlittle bit by that, but our
Dialogue: 0,0:36:52.00,0:36:56.00,Default,,0000,0000,0000,,other one here is not going to\Nbe true, so we just have all of
Dialogue: 0,0:36:56.00,0:36:58.00,Default,,0000,0000,0000,,the above is not correct,\Nso we have this one.
Dialogue: 0,0:36:58.00,0:37:02.00,Default,,0000,0000,0000,,So if we had up those, that's\Nactually a pretty good score.
Dialogue: 0,0:37:02.00,0:37:07.00,Default,,0000,0000,0000,,And so you could think about,\Nsay, what would be true of a
Dialogue: 0,0:37:07.00,0:37:11.00,Default,,0000,0000,0000,,complex that was linear along\Nz, what would be the most
Dialogue: 0,0:37:11.00,0:37:13.00,Default,,0000,0000,0000,,stabilized, for example.
Dialogue: 0,0:37:13.00,0:37:16.00,Default,,0000,0000,0000,,So these are the kinds of\Nquestions you can get, and
Dialogue: 0,0:37:16.00,0:37:20.00,Default,,0000,0000,0000,,I think there are a few\Non the problem-set.
Dialogue: 0,0:37:20.00,0:37:24.00,Default,,0000,0000,0000,,All right, so let's come\Nback together now and talk
Dialogue: 0,0:37:24.00,0:37:26.00,Default,,0000,0000,0000,,about magnetism again.
Dialogue: 0,0:37:26.00,0:37:30.00,Default,,0000,0000,0000,,So, we said in the beginning\Nthat magnetism can be used to
Dialogue: 0,0:37:30.00,0:37:35.00,Default,,0000,0000,0000,,figure out geometry in, say, a\Nmetal cluster in an enzyme, and
Dialogue: 0,0:37:35.00,0:37:39.00,Default,,0000,0000,0000,,let's give an example of\Nhow that could be true.
Dialogue: 0,0:37:39.00,0:37:44.00,Default,,0000,0000,0000,,So, suppose you have a nickel\Nplus 2 system, so that would be
Dialogue: 0,0:37:44.00,0:37:49.00,Default,,0000,0000,0000,,a d 8 system, so we have group\N10 minus 2 or d 8, and it was
Dialogue: 0,0:37:49.00,0:37:51.00,Default,,0000,0000,0000,,found to be diamagnetic.
Dialogue: 0,0:37:51.00,0:37:56.00,Default,,0000,0000,0000,,And from that, we may be able\Nto guess, using these kinds of
Dialogue: 0,0:37:56.00,0:37:59.00,Default,,0000,0000,0000,,diagrams, whether it has\Nsquare planar geometry,
Dialogue: 0,0:37:59.00,0:38:03.00,Default,,0000,0000,0000,,tetrahedral geometry,\Nor octahedral geometry.
Dialogue: 0,0:38:03.00,0:38:08.00,Default,,0000,0000,0000,,We can predict the geometry\Nbased on that information.
Dialogue: 0,0:38:08.00,0:38:11.00,Default,,0000,0000,0000,,Let's think about\Nhow that's true.
Dialogue: 0,0:38:11.00,0:38:14.00,Default,,0000,0000,0000,,We have a d 8 system.
Dialogue: 0,0:38:14.00,0:38:17.00,Default,,0000,0000,0000,,Think about octahedral\Nfor a minute.
Dialogue: 0,0:38:17.00,0:38:24.00,Default,,0000,0000,0000,,Are there two options for how\Nthis might look in this case?
Dialogue: 0,0:38:24.00,0:38:26.00,Default,,0000,0000,0000,,Is there going to be a\Ndifference in electron
Dialogue: 0,0:38:26.00,0:38:32.00,Default,,0000,0000,0000,,configurations if it's a weak\Nfield or a strong field?
Dialogue: 0,0:38:32.00,0:38:36.00,Default,,0000,0000,0000,,So, write it out on your\Nhandout and tell me whether
Dialogue: 0,0:38:36.00,0:38:54.00,Default,,0000,0000,0000,,it would be true, think\Nabout it both ways.
Dialogue: 0,0:38:54.00,0:38:58.00,Default,,0000,0000,0000,,Is there a difference?
Dialogue: 0,0:38:58.00,0:39:00.00,Default,,0000,0000,0000,,So, you would end up\Ngetting the same thing
Dialogue: 0,0:39:00.00,0:39:01.00,Default,,0000,0000,0000,,in this particular case.
Dialogue: 0,0:39:01.00,0:39:05.00,Default,,0000,0000,0000,,So if it's a weak field and\Nyou put in 1, 2, 3, then jump
Dialogue: 0,0:39:05.00,0:39:09.00,Default,,0000,0000,0000,,up here, 4, 5, and then you\Nhave to come back, 6, 7, 8.
Dialogue: 0,0:39:09.00,0:39:13.00,Default,,0000,0000,0000,,Or you could pair up all the\Nones on the bottom first and
Dialogue: 0,0:39:13.00,0:39:16.00,Default,,0000,0000,0000,,then go up there, but you\Nactually get the same result no
Dialogue: 0,0:39:16.00,0:39:21.00,Default,,0000,0000,0000,,matter which way you put them\Nin, the diagram looks the same.
Dialogue: 0,0:39:21.00,0:39:24.00,Default,,0000,0000,0000,,So it doesn't matter in this\Ncase if it is a weak or strong
Dialogue: 0,0:39:24.00,0:39:27.00,Default,,0000,0000,0000,,field, you end up with those\Nnumber of electrons with the
Dialogue: 0,0:39:27.00,0:39:31.00,Default,,0000,0000,0000,,exact same configuration.
Dialogue: 0,0:39:31.00,0:39:33.00,Default,,0000,0000,0000,,So, we know what\Nthat looks like.
Dialogue: 0,0:39:33.00,0:39:36.00,Default,,0000,0000,0000,,Well, what about square planar.
Dialogue: 0,0:39:36.00,0:39:38.00,Default,,0000,0000,0000,,So let's put our\Nelectrons in there.
Dialogue: 0,0:39:38.00,0:39:41.00,Default,,0000,0000,0000,,We'll start at the bottom,\Nwe'll just put them in.
Dialogue: 0,0:39:41.00,0:39:44.00,Default,,0000,0000,0000,,I'm not going to worry too much\Nabout whether we can jump up or
Dialogue: 0,0:39:44.00,0:39:48.00,Default,,0000,0000,0000,,not, we'll just go and pair\Nthem up as we go down here, and
Dialogue: 0,0:39:48.00,0:39:52.00,Default,,0000,0000,0000,,then go up here, and now we've\Nput in our eight electrons.
Dialogue: 0,0:39:52.00,0:39:56.00,Default,,0000,0000,0000,,So, how close these are, we're\Njust going to put them all in.
Dialogue: 0,0:39:56.00,0:39:59.00,Default,,0000,0000,0000,,We're just going to be very\Ncareful not to bump up any
Dialogue: 0,0:39:59.00,0:40:04.00,Default,,0000,0000,0000,,electrons there unless we\Nabsolutely have to, because d x
Dialogue: 0,0:40:04.00,0:40:08.00,Default,,0000,0000,0000,,squared minus y squared is very\Nmuch more destabilized in the
Dialogue: 0,0:40:08.00,0:40:11.00,Default,,0000,0000,0000,,square planar system, so we're\Ngoing to want to pair all
Dialogue: 0,0:40:11.00,0:40:15.00,Default,,0000,0000,0000,,our electrons up in those\Nlower energy orbitals.
Dialogue: 0,0:40:15.00,0:40:18.00,Default,,0000,0000,0000,,So even if we sort of\Ndid it a different way,
Dialogue: 0,0:40:18.00,0:40:19.00,Default,,0000,0000,0000,,that's what we would get.
Dialogue: 0,0:40:19.00,0:40:22.00,Default,,0000,0000,0000,,So we're going to want to pair\Neverything up before we go
Dialogue: 0,0:40:22.00,0:40:25.00,Default,,0000,0000,0000,,up to that top one there.
Dialogue: 0,0:40:25.00,0:40:26.00,Default,,0000,0000,0000,,So there's our square planar.
Dialogue: 0,0:40:26.00,0:40:28.00,Default,,0000,0000,0000,,Well, what about tetrahedral.
Dialogue: 0,0:40:28.00,0:40:31.00,Default,,0000,0000,0000,,How are we going\Nto fill these up?
Dialogue: 0,0:40:31.00,0:40:37.00,Default,,0000,0000,0000,,Do we want to pair first, or\Nwe do want to put them to the
Dialogue: 0,0:40:37.00,0:40:40.00,Default,,0000,0000,0000,,full extent possible singly?
Dialogue: 0,0:40:40.00,0:40:43.00,Default,,0000,0000,0000,,Single, right, it's going to be\Na weak field, there's not a big
Dialogue: 0,0:40:43.00,0:40:46.00,Default,,0000,0000,0000,,splitting here between these,\Nso we'll put them in, there's
Dialogue: 0,0:40:46.00,0:40:53.00,Default,,0000,0000,0000,,1, 2, 3, 4, 5, 6, 7, 8.
Dialogue: 0,0:40:53.00,0:40:55.00,Default,,0000,0000,0000,,All right, so now we can\Nconsider which of these will
Dialogue: 0,0:40:55.00,0:40:58.00,Default,,0000,0000,0000,,be paramagnetic and which\Nwill be diamagnetic.
Dialogue: 0,0:40:58.00,0:41:01.00,Default,,0000,0000,0000,,What's octahedral?
Dialogue: 0,0:41:01.00,0:41:05.00,Default,,0000,0000,0000,,It's paramagnetic, we\Nhave unpaired electrons.
Dialogue: 0,0:41:05.00,0:41:08.00,Default,,0000,0000,0000,,What about square planar?
Dialogue: 0,0:41:08.00,0:41:10.00,Default,,0000,0000,0000,,Square planar's diamagnetic.
Dialogue: 0,0:41:10.00,0:41:11.00,Default,,0000,0000,0000,,And what about tetrahedral?
Dialogue: 0,0:41:11.00,0:41:14.00,Default,,0000,0000,0000,,Paramagnetic.
Dialogue: 0,0:41:14.00,0:41:20.00,Default,,0000,0000,0000,,So, if the experimental data\Ntold us that a nickel center in
Dialogue: 0,0:41:20.00,0:41:23.00,Default,,0000,0000,0000,,an enzyme was diamagnetic, and\Nwe were trying to decide
Dialogue: 0,0:41:23.00,0:41:27.00,Default,,0000,0000,0000,,between those three geometries,\Nit really seems like square
Dialogue: 0,0:41:27.00,0:41:31.00,Default,,0000,0000,0000,,planar is going to\Nbe our best guess.
Dialogue: 0,0:41:31.00,0:41:34.00,Default,,0000,0000,0000,,And so, let me show\Nyou an example of a
Dialogue: 0,0:41:34.00,0:41:39.00,Default,,0000,0000,0000,,square planar system.
Dialogue: 0,0:41:39.00,0:41:44.00,Default,,0000,0000,0000,,And so this particular nickel\Nis in a square planar system.
Dialogue: 0,0:41:44.00,0:41:50.00,Default,,0000,0000,0000,,It has four ligands that are\Nall in the same plane, and it
Dialogue: 0,0:41:50.00,0:41:54.00,Default,,0000,0000,0000,,is a square planar center for a\Nnickel, so that's one example.
Dialogue: 0,0:41:54.00,0:41:58.00,Default,,0000,0000,0000,,And this is a cluster\Nthat's involved in life
Dialogue: 0,0:41:58.00,0:42:01.00,Default,,0000,0000,0000,,on carbon dioxide.
Dialogue: 0,0:42:01.00,0:42:04.00,Default,,0000,0000,0000,,All right, so that's\Ndifferent geometries,
Dialogue: 0,0:42:04.00,0:42:05.00,Default,,0000,0000,0000,,you're set with that.
Dialogue: 0,0:42:05.00,0:42:09.00,Default,,0000,0000,0000,,Monday we're going to talk\Nabout colors of coordination
Dialogue: 0,0:42:09.00,0:42:12.00,Default,,0000,0000,0000,,complexes, which all have to do\Nwith the different geometries,
Dialogue: 0,0:42:12.00,0:42:16.00,Default,,0000,0000,0000,,paired and unpaired electrons,\Nhigh field, low spin,
Dialogue: 0,0:42:16.00,0:42:19.00,Default,,0000,0000,0000,,strong field, weak field.
Dialogue: 0,0:42:19.00,0:42:21.00,Default,,0000,0000,0000,,Have a nice weekend.
Dialogue: 0,0:42:21.00,0:42:22.00,Default,,0000,0000,0000,,