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Lecture 20. NMR Applications/ Review


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Title Lecture 20. NMR Applications/ Review
Title of Series Chem 131B: Molecular Structure & Statistical Mechanics
Part Number 20
Number of Parts 26
Author Martin, Rachel
License CC Attribution - ShareAlike 3.0 Unported:
You are free to use, adapt and copy, distribute and transmit the work or content in adapted or unchanged form for any legal and non-commercial purpose as long as the work is attributed to the author in the manner specified by the author or licensor and the work or content is shared also in adapted form only under the conditions of this license.
DOI 10.5446/18929
Publisher University of California Irvine (UCI)
Release Date 2013
Language English

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Subject Area Chemistry
Abstract UCI Chem 131B Molecular Structure & Statistical Mechanics (Winter 2013) Lec 20. Molecular Structure & Statistical Mechanics -- NMR Applications/Review. Instructor: Rachel Martin, Ph.D. Description: Principles of quantum mechanics with application to the elements of atomic structure and energy levels, diatomic molecular spectroscopy and structure determination, and chemical bonding in simple molecules. Index of Topics: 0:06:48 NMR Applications/Review 0:10:26 Going Through the Process 0:15:59 Sidechain Correlations - TOCSY 0:17:54 Mistic Structure 0:18:59 Relative Sizes of Interactions 0:19:40 Quadrupolar Nuclei 0:25:19 Spin 1 0:27:34 Bicelles: Membrane Mimetics 0:29:39 ^(2)H Spectra 0:31:59 Multiple Lipid Phases 0:35:56 NMR Spectroscopy Worksheet
the morning what's that I think it started on time today is as humanitarian exam Friday on Saturday morning to talk about any more applications and just some stuff that's hopefully interesting and maybe Tyson things together that we've been looking at and then at the end we talk a little bit about the kinds of problems that might be an easier exam but I'm happy to answer general sorts of questions about it right now 21 has them yes I know that the level of the electric of that was sections of well so serious that the problems I signed address the problems in the back of the other there are a bunch of example problems in the book there are things in the book that we did not go over at all and that's just fine tuning for instance in the Chapter 11 there's a whole bunch of stuff about how work and it's neat and I hope you read it it's you know it's it's nice for your information but I'm not be tested on its maiden cover all we don't have time to do everything so if you want extra practice problems from the book I would say look for ones that are similar to once I signed a similar to things that we did in class and then that might give you an idea which ones are going to do there are definitely some that are going to help you with specifically means any material anything else the year that Hermes polynomials if you need to know me I will for the most part I'm not going to give you the equations that something like that where you need a giant table of wave functions were not expected to know that I will say if you know you need to pull out your can 1 notes and go over molecular orbitals of diatonic molecules and you know remember which way the signal and high orbitals going energy for a different diet ,comma molecules is a good time to review that and there's no question we're here we where did you get that idea where did you get the idea that you don't need it draw molecular orbital gliders I need to yeah I just said If you need to review that nature you go review it before the exam Simon the exam question is not going to be drawn molecular orbital diagram of your Florian but In order to come up with a term symbols for diatonic molecules you're going to need to know things like the symmetries of the different molecular and so on I'm just recommending that's a good thing review if you don't remember yes In terms in your hearts to file yeah 1 of these sales yeah I was wondering what was going on holiday I have to say some all while soap so plus and minus so I think a lot of this ongoing and other other really specific questions I'm going to defer to office hours in the review session tonight but that the plus and minus refers to Dana that I can answer quickly it refers to the cemetery about a reflection claimants through the Internet Clear access so remember GNU use whether it's even and odd with respect to convergence and then plus line is likely headed to nuclei and then there's a plane going here containing into nuclear accessing and reflected top-to-bottom there and if you get the same thing it's plus if you get a negative sign it's like so that's how you tell that and so you know if you if you can remember all the stuff and doing your head and you get the right answer that's fantastic but if you I don't remember you whether these molecular orbitals Aegean office copier had you might need a about picture and look at it and say she might wanna make sure that you can do that relatively quickly you don't you don't have to get credit but units that's 1 really good way to figure it out and also if you the more of you work you show the work partial credit and that you have to make mistakes all other things I should mention the rules are the same as last time you get a cheat sheet and you can use a calculator please don't store texting your calculator that's cheating by using it as a calculator is just fine I what else we need to post the seating chart but that'll be up today or tomorrow Everybody did a pretty good job last time about getting in and getting seated please try not to do it even more efficiently this time alone the exam it's kind along again so no this is this is good actually I swear because if I don't know if I don't have to do it on purpose and rather have it be a little long so that everyone runs out of time rather than have to be more selective about what to put on it because it's a more effective measure what everybody knows so if I for instance if I only put in a March spectroscopy on it but it's really short if that's the 1 thing you didn't understand unit do really badly and it's not very far because it didn't test the and all the other things that we won over so I'd rather put more different things on it and measure what everyone knows more effectively and yet that means everyone's gonna run out time and it'll be a little stressful but it's a it's a better measure of what people can do so you know just make sure that we all try to get here on time and and get organized quickly realized it agreed about that last yes there is a recession of John Mark interior doing that and it's 2 nights and its on it starts at 8 o'clock and what we're missing any games and remember 1 of 4 Roland OK good alright so
any other general kinds of questions about the exam at the it's going to cover rotational vibrational spectroscopy things like interpreting spectra we didn't do all that said before we can offer the end of the material from Inter Milan and there will be selection rules had you know which transitions happen which ones don't you have to calculate for at least breakdown Frank common factors for electronic transitions there will be a sunny some things like looking at a spectrum and inferring what the energy level diagram of the system looks like and vise versa stuff like that you need to know about anymore but both in terms of looking at matrices for the the angular momentum operators and also you know the quantum-mechanical representation of more undertaking on a pretty basic level we on the gotten that far into it that there's going to be a little bit and also being able to draw in more spectrum that are taken under various conditions questions OK so that's a that's a good question so that so I I regret unclear question on this so the transition to a new when you were using the transition dipole that's just telling us OK is this transitional Latin markets a yes-or-no questions just Oregon C signaled yesterday that the franc common factor tells us be that tells us something about the amplitude of the signal that receipt and so on you know you could you could also get from the Franklin factor that the amplitude that signals the 0 because the states have 0 but it will also if it's not 0 that will give us the actual number for the the intensity of the spectrum so I will try to be extremely clear about what I'm asking for in those kinds of questions on again for this exam I recommend reading the directions really carefully because there are a lot of things where I have set things up a certain way to try to save you time so it is long but there are things that could take even more time if you don't follow the directions so please do if you don't understand and feel free to ask us so we have the worst case scenario is organization sorry about the incident question right now but you can ask I'd rather have a really understand what's going on and off OK so that actually gotten worse asked yeah this region editing were were pretty good at looking around and then catching people's questions we can have a really getting up and running around so you please just raise enhancing your seat will come around and talk to you break let's talk about it more so last time at the end they talked about two-dimensional anymore and as by extension multidimensional animal on how we use this to go about solving structures of molecules and we saw a simple example of an amino acid in a complex example of a two-dimensional spectrum I want to show you a little bit more about how we actually solve structures of molecules using us so we go through this process we start with two-dimensional or three-dimensional or even higher dimensional spectra and then we have to go through these collections of Spector an assignment so we determined specifically which amino acid which amino acid in the sequence to these particular keeps belonged to and again you need highly multidimensional spectrum do that you have to walk through the the backbone and even recognize particular spin systems and say OK that's that wants to Bailey and then if you go across the backbone looking at you know HC and find experiments and going through through the the protein that background alright now I have a building next to an nicer Lucy and you can start to eliminate about like how many sites in the protein contained that sequence and you made the proteins so you know that and so we go through and walk through the whole sequence and smoke with an address for every Proton carbon and nitrogen then we use some additional more long-range experiments to measure summer restraints on the three-dimensional structure so here we we're interested in doing is measuring things like that couplings if it's a solidarity oriented sample or In use nuclear has effect cross relaxation terms these are things that tell us about the distance between 1 part of the protein and others so now
will have to say and I coupling between availing that's on 1 side the protein in the amino acid chains and Patrick defended somewhere else in the primary sequence and the only way that they can be close together is because the protein is folded up and so these restraints tell us more about the distance Of course since we have a whole lot of them we can't measure the distance is very precisely if we had specifically labeled samples with 1 c 13 and 1 in 50 we could the measure the decor coupling between those 2 nuclei and get the distance between them too many many decimal places we would have a very precise number people do that it's useful experiment however for protein structure determination anything that's that's morally complicated it's not so good because in that case if I'm doing a proton carbon correlation if I put in by transforming position from protons stew they don't just transforming position to the carbon there directly attached to it that mechanization also leaks all around and gets diffused at different points in the the protein because we have a lot of her constancy 13 and 15 all around and so that means that we get more information which is a good thing but it dilutes are mechanization and we don't have these really precise distances so what are we do we basically take these these disincentive having his distance measurements very precisely the kind of been them into small medium and large essentially so we can say right these pairs of residues are very close together here some that are in the middle and here some of the ones that are really far apart and then feed all of this to a dynamics type simulation that put that uses those measurements as restraints on the structure and so 1 of them on its own is not very precise but because we have thousands of them you can put all that in the simulation minimize the energy and hopefully get a reasonable structure yeah and then of course you get this family of structures and we have to go back to reject some of these things and that the longer the assignments are on things like that and we iterate through budget times and then eventually get a structure that looks like it's starting to converge so this is a solemn more structure we've talked about crystal structures before you were defecting X-rays and sawing of solving electron density there are crystal structures and a more structures in the protein databank and yet they're all in their early kind of put anything you want in the PDB by the different kinds of structures in the different information because they're they're measured quite differently and there there really complimentary so crystal structure tells you I think it's a snapshot of a protein that moralist mobilize because in this region crystal lattice and it gives you really high resolution hopefully if the data is good picture of world the Adams art but it doesn't tell you about other things like mobility so an anonymous structure said notice that this this particular protein which is it's Janice Chris Collins was sold in my lap on it has this this tale on the bottom of the Inter and and you can see in the family of structures it doesn't quite convergence it's flopping around all over the place you can save know well that's not as nice as a crystal structure of things like down but that's kind of missing the point is is telling you information it's telling us that in fact that internal tale is flopping around its mobile as opposed to the C-terminal tell which you can see a on the right which is kind of tucked up into the protein and it has really well-defined confirmation so these are 2 different ways to to get structures and they're really complimentary so going back to the process of how we get this if we look at some of the some correlations so I mentioned that we can see individual spin systems and identify what kind of amino acid as fears of multidimensional sequence color Toxey that tells us you know here we got protons chemical shifts and carbon chemical shifts correlated if you're used to looking at these things usually 20 amino acids come up in normal proteins you get really good at seeing that the patents for the spin and identifying the amino acids so 1 of the 1st things that you do is go through something like a Toxey and identified the the proton carbon correlations and see it just label things as 2 types of amino acids so near here just some new some examples of stuff that we can see where it is because of the chemical shift so for instance these arms the beta protons choose show up in the air between 2 and 3 ppm in the proton dimensions the same thing with these
academic protons and then we can walk through the backbone so now each of these places is from a three-dimensional spectra we've got we've got to proton and end of carbon chemical shift again and we're going through the backbone and each of these lines that and Brian is a correlation between amino acids that are next to each other in sequence and so we know exactly what's next White and remember we make the protein so we know the primary sequence if you took a protein of unknown sequence and gave it to an marched across this insidious all the structure we would have a really hard time it's so it's not something you can typically do arts
amusing example of a structure that was solved using this kind of technique here with some representative data on this protein is called Mystic it's a membrane protein that helps other membrane proteins fold up so it's a it's very popular in animal labs this fall was not solved reminder is from and I want to point this out because we can do these kind of correlations between nuclei not only among nuclear editor in the same molecule but we can do it across interfaces between 2 molecules so 1 of the things that affect our Greek group dead in the structure as they look to correlations between the protein and particular parts of the membrane and so they were able learn a lot about exactly how sitting in the membrane from looking at a March structure OK so that 1 application about a molecule looking at where we can go with that beyond identifying simple molecules I want to talk about another 1 again so we've seen this slide before looking at the relative sizes of interactions and we're to come back to the quadruple interaction so we just kind of version offers you know hey don't really see it and liquids except that it makes the it makes adjacent nuclei relaxed by if we're talking about solid-state model particularly materials ,comma according to the EIA really important there's a whole field of looking at complex solid materials that's that's extremely important in chemical engineering and particular and also physical chemistry where people develop techniques to look at a quarter point of OK so here's a periodic table showing the and moderately II and everything that is blue has only spin one-half nuclei and everything that's White has no American nuclear work so radioactive that it doesn't stick around long enough to tell and everything that's in pain is something that has quadrupled nucleus and so do you know what I say different different elements have different kinds of nuclei that could be spent 1 half or quarter pole notice that hydrogen kind has both that's because it has different isotopes so it has protons witches than one-half and also has deuterium which are been 1 so some of these things to have both that even given that if you look at the periodic table a whole bunch of the nuclei that are better there are cortical audience been greater than one-half and if we weren't able to study that and deal with those will be missing out on a lot of what's going on in chemistry particularly in In Organic Chemistry and Materials kinds of applications OK so what is it mean that something is "quotation mark report all a quarter :colon nucleus is something that doesn't have a spirit distribution of charging nucleus and you know what is that what exactly does that mean what's the structure of the nucleus look like that's beyond the scope of what we're doing and you have to get into some serious nuclear physics to to understand exactly what's going on but we can understand it on a conceptual level so the quadruple moments of the nucleus is in effect is interacting with the electric field gradient and that's what produces some interesting line shapes that can give us information about the structure of the material or you make a spectrally messy depending on what's going on this interaction is an isotropic it depends on the orientation with respect to the magnetic fields you know we've talked about things like that couplings and chemical shift anisotropy all of these things behave as a secretary cancer with respect to magnetic field so that means that we can spin spend about the magic angle and Abidjan out the magic angle I don't know if we if we talked about this before they tell you that magic angle standing there are now no OK it is a little section about the book so essentially what it is is we have these interactions that we have the second-ranked had by poor coupling chemical shift anisotropy magnetic susceptibility differences things like that and in a liquid these all average out because molecules moving around isotropic still the experiment in the solid that's not true they're stuck in some regions place you know whether it's a resource glass or something like that and they're not averaged out by the murder so if we just had a spectrum of static solid lifetimes times we big Macs because we have very complicated interactions federal overlapping if we want to simplify that spectrum then often what we do Is will spend the magic and and all that is is the angle where the 2nd order of 100 polynomial happens to go 0 and you can think about in a simple geometric way like this if you imagine a Q so behavior xyz cordon system there's a cure drop a line between 2 vertices of accuse the furthest apart and think about that angle that's the magic and also if we spend about that were averaging in the x y and z Jeanette direction all equally and so that helped us get rid of a lot of these interactions there that behave as 2nd rate tenses in space so the quarter pole interaction is more complicated than that it behaves as a fourth-ranked had served at least that the 2nd particle termed and suspending the magic angle doesn't make it go away completely because there's not just there's not just 1 degree of freedom you need you would need to do degrees of freedom to average about completely so 1 way you can do that is by spending it 2 different angles during the experiment and people have done that we actually do in my life for different reasons or you can used techniques where 1 of the averaging policies is done an actual space and the other 1 is Dunstan space all that is a little more advanced over again for now bolts looks just look at what the interactions look like OK so here's what the quarter pole or Hambletonian looks like so there's a dependence on the electric quadruple moment which again has to do with this field radios and it also
depends on the spin quantum number for this nuclear selected be it goes in increments of a half so it could be 3 halves it could be 1 it could be 7 have served their own article in of the I'm with all kinds of different spin on numbers it also depends on this electric field gradient tenser and so here's what we get for something like it's been 1 nucleus so instead of just having to possible levels of up to possible values for the spin angular momentum here we can 1st then one-half we're plus or minus 1 half and we interpret that as up-or-down relatives the magnetic field if we have a spin 1 that has these 3 states with them said all values of 1 0 and minus 1 and so that means that when we look at it and what spectrum if we just have 1 nucleus and suspend 1 it's going to give us a Dublin because it has these 2 possible transitions and so on what would it be nice for you know about this at this point as far as horrible where you should know that they exist you should know what the spin states look like and you should be able to do simple things like great matrix elements for operators like easy and I lost my minus stuff you know stuff like that that we went over and passed the year simple ones In these kind of disease and that is about it only I guess the other thing is you should also be able to draw MR spectra for them as we did in some of the homework problems you said are you have you noticed in 1 half coupled to a spinner 3 houses 1 of the structural like you should know that those but that's about it so let me tell you a little bit about an application of this so that we work on my group so again the main application of this year in you out in the field is solids Sumiton materials that you aluminum silicate glasses are are popular ones but all kinds of materials were the mistake that you want to look at is a solid and united early Christians he can do crystallography Zia lights I all kinds of things like that here is an example for my group of so we don't work and on a solid materials except for proteins occasionally but 1 thing that we use water according the I-4 is looking at orientation in biomolecules in the context of memories so we will look at membrane proteins stuck in a membrane in there in as close to native but conditions as we can member proteins are really important and it's so it's very useful to have the structures CC numbers thrown around like membrane proteins make up a 3rd of the pretty and something like 60 per cent of all drug targets and the reason for that is that you know these are really water allowing things to pass in and out of ourselves including information so all of our senses are there any other the In tenders for those remembering proteins for instance and all kinds of other things involving transporting food into the cell waste out of the solve all that all us remember so it's really useful give us all the structures and you figure out how to design drugs to interact with them however it's difficult to get the structures because they don't crystallize very easily they need interaction with membranes and also looking at them by solutions to tomorrow's really difficult because they have to be stuck in memory so were interested in developing a more techniques to do this 1 of the things that we do yoga and other groups do this as well so it's a pretty large fields were interested in putting these memories proteins in membrane the medics that our Tractebel to anymore but they're realistic enough and so on the system that we often use for that that's that's again pretty common is this mixture of shortening wanting lipids that self assemble into oriented memorandum and here I'm I'm showing them as a little cartoons is little disks that aligning the magnetic field they don't look exactly like us but 1 of the trucks that we use and with generated molecules is that we put D 2 0 in with our systems and you know again deuterium is a spin 1 so if it's in in an isotropic environment where everything is not getting averaged out by the molecular motion then will see a Dublin and so when we want to mapped out what kinds of phase transitions souls are undergoing you were interested in having a system that is aligned so that we can take our membrane protein in it and do a moron and if you look at this cartoon again don't look exactly like that issue but the the important part is if you have these mixtures at low concentrations we get tiny little mice also there are no good because the protein will fit in there in its native conformation and if we get all the way up to high temperature we have large vesicles which our again nobody cares there had a genius you know we're not going to see a good alignment of our sample each protein is an enemy in the environment and in between we get these oriented systems that are useful for looking at the protein structure and so the way we measure that is we windy too well and we take spectra of the deuterium so you know again a lot of times you hear about take here and more specter of organic molecules endeavoring solvents because you don't want to see a bunch of probe of protons from solvency think that deuterium is silent it's not it's good anymore nucleus it's just that it suspend 1 and so if you want to look at it we have to tune the probe to a different frequency and actually investigated interior and so here were just using the G 2 0 as a probe to spy on the by souls Intel's whether they're oriented but he could also put deuterium on lipid molecules themselves and people do that but it's really expensive as opposed to throwing 92 0 which is cheap so it's so it makes a good starting point for this kind of study it's cheap and it's easy we can tell whether things are oriented or not so that enables us to do
things like go look at In his approaching from the former Philip organism that if you see here in our in our particular Beisel recipe that we made here that details were too much to go into 4 right now but if you look at this at 55 degrees the distance between the 2 peaks of the double it is really far apart that means we have a lot of orientation in the sample and that enables us to look at this from a filet protein at a temperature that's close to it's operative temperature which is important and we want you to study these things at the temperature where they're actually acted OK so I pronouncements done with Panama
and all from you know so basically that's everything that's being that we need to know for the 2nd term there 2nd to get the document camera thinks that happened looks .period little bit about some of the kinds of of problems that there might be at
time it anything that as I are so obviously we don't have time in 15 minutes or whatever that's left to go over the all the kinds of problems that could be on the exam but I just wanna start sort of close to To the End of what we talked about where we had maybe a little bit less time to practice and go over a few of these problems so sorta last thing that we thought that we talked about it in a March so let's look at that OK so the idea here also look at that party here yeah all of my lectures are always post on the website that there's a video and my greatest dynasties paper on on the website notes that there is a video OK so the ideas we wanna look at the current a couple and more spectrum of this molecule so let's look at how we want to promise so it's a proton spectrum so the 1st thing you want to do is label where access so chemical share proton ppm 0 goes over here it's going and around 12 that's important part problem all things that we should be worried about when you're predicting that a more spectrum of of a compound 1 is how many protons are there they're not equivalent and you know make sure that you read the directions really carefully so in this particular case I remember when I give this exam it was it was a couple years ago I said you know sketched the currency's steps a spectrum of this molecule and some people only wrote down the answer for the protons that are labeled a and B. but we have been read the directions in the you in this case it was probable thinks so just you make sure your make sure you're actually following what the questions asking for a case of harmony protons do we have the an equivalent but when you think how many different kinds of do we have yes so we've got these guys and this 1 and what he thinks are this 1 and that 1 equivalent now right of of symmetry OK so the next thing that we want to worry about is the chemical shifts and 1 thing that I am going to give you as part of this exam is a basic table of chemical shifts as far as we're different functional groups show up for protons because I'm not really worried about anyone memorizing those numbers I'm also just said I'm going to roughly stick in at this point the main thing worried about and that is getting stuff sorted in the right order as far as as work falls on the spectrum here so I'm not going to argue with anyone about whether something shows up at 7 ppm a 7 . 5 ppm it's it's not important the important thing is getting things in in roughly the replaces and I will give you a table used that OK so 1st look look at the map of Europe so those are going to be Over here you know close to 2 hours 0 between 0 and Tuesday and so we've got to overcome when he think which 1 is any closer to 0 this 1 or this 1 on the bottom line yeah how do you know the Federal on top of this winter and shouldn't have worried that the were that we need to spend lunchtime on OK so the first one were and rises bottom 1 so that's going to go somewhere you know will put it at 1 point something the fiance but you may be around to what you know full well guess who's got here somewhere on we also have to worry about splitting OK so what is the signal that can look like Is it going to be a single letter a doubleheader for quite a while yet triplet so we have toxic although the Indian called the sea f yes that's arbitrary but that's fine OK so this is the Our now however the leftover here B so we already said it shows up a little bit further To the left and the other 1 what is a single look like yeah it's the same way because it it is not a Split by anything OK so then the next thing we have some aliphatic Proton here so that's the story that's the ICH too and that's what by its neighbor the methyl group so it's going to be a quartet and that's you in here somewhere then again this is sort of the level of you know terror that I expect with the you know what exactly where you put the at
the chemical shift questions last you are so right I was not thinking of those things altogether so yet either USA issues you can have but again I'm going to give you a table that so it'll it'll be helpful easier to keep track of yes you know it's at some point it just gets too hard to draw so yes ideally if you had all the time in the world you should draw the problem so that there the same so that the relative intensities indicate how many there are but in reality here like on this quality withdrawing telling difference between 1 proton and 3 of this not so concerned about it so yeah it's ideally you should know that but it's a it's not necessary to trade in case with the of a so we've got our our own any our methyl and aliphatic protons and then I'm going to draw up a break in the middle of this axis because now I bet everything all spread out and so I want indicate that there's some stuff in the middle before we get to know the the aromatic protons and so those are all going to be sir over here ends as far as what order you get the men you know for again for this this level of problem as long as you get something reasonable it's fine here at the ordinary pretty close together ends you're here 2 of them are going to be double it's because they're displayed by in 1 neighbor and 1 in the middle is going to be a double doublets and here's something about intensities that I do actually wanna see so we have a quartet looks like the middle one's a higher intensity In a doubling of doublets has all of the same height and so I knew I would like to see that and so you know crude as the going is going to be like sitting in the stands and so I just wanted to go through this to show you know I know these problems we have to draw something the kind of hard I was just sort of what level of detail I expect and you know what kinds of things are not necessarily going to really count against you at this point because I know you have a finite amount of time and you can't do everything at the time constraints so I'm worried about you know and you get roughly the right places 1st chemical shift during our table and getting the splitting patterns right questions about the kind of thing that goes on in the area also at Dublin double its means Split by 1 neighbor over here and then another neighbor over here so it's quite to non-Apple what proton if it's a quartet minutes played by 3 approval hurdles he said it's a different effect yes the yet so that's that is true if it were if it were identical than it would have 2 identical neighbors OK so now let's look at the next 1 will be OK so we said explaining the spawning pattern Of the residents of Proton a separate Monday we said is a double Dublin and then the question is don't just described it explained the physical reason for the effect so just describing it would be you write down it's a double double it's you know OK but that doesn't say that you understand exactly what's going on so you would need to say something like its foot by 2 knowledge of what neighbors and you know even better if you mentioned that the the reason for the splitting is that you want its neighbors can be the opera down and that adds to her subtracts from the media magnetic field so this is definitely the kind of stuff that you might see come up what see what else do we have in relationship to this I might also ask you about things like the here I mentioned that we are quickly running out of time I had a huge planned for all the examples that we can go over and of course the stuff always takes longer than that I thought so we'll have to do some of that office hours and enable share some of it with the TAC is the review session as well OK so we also have we don't have time to do the whole thing that was just talk to reveal that this last question sketch the Asian accent marks specter for inmates to spin system where a is a spin-one in 1 half and the J. coupling is 25 per so OK so what should tell you is that the other called a annex that means there are 2 different types of nuclear isolate all show up in the same spectrum so the a spectrum and we expect the worst for different things so you know maybe the areas a deuterium and done or maybe 10 and 14 I guess that's a more realistic example and X could be Proton and so you're not going to see the and 14 in the Proton in this inspectors have to drop 2 separate things and so you know here's our axis I didn't tell you what nucleus the says so you can't get too excited about the actual values but you know that without the splitting aces and won and so it's going to have a Dublin if it's just by itself if it had no interaction with anything would have a Dublin then we know that it Split 2 protons and so each of those protons organist played In 2 it's a misplayed into a truckload but it had to peaks to begin with so what that looks like it's a doubling of triplets and the J. coupling is 25 hertz so that's this the distance between them and I will let you figure out the 2nd part of the problem brother proton spectrum when it slipped by that Spain 1 OK
we're out of time and if you want more examples from the office hours today and tomorrow and the rejection
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