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Lecture 02. Molecular Orbital Theory (Pt. 2) & Energy.

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OK let me take you back to where we left off on Wednesday but on Wednesday we started talking about orbitals we're going to spend the rest of this quarter using arrow pushing as a way to describe orbital interactions that we really need to be comfortable with these 3 types of Waigel's atomic orbitals hybrid atomic orbitals and molecular and really the
rest of this quarter is going to be molecular orbitals so I introduced you to this idea of molecular orbital
interaction diagram that allows us to graphically depict something we don't see when we draw Lewis structures we don't see when we draw Lewis structures as is the energies of the electrons that attacking that's what we don't see and sold the molecular orbital interaction diagram is designed to show you graphically the energetic consequences of an interaction like this let's just imagine that water doesn't ascend to attack on chloral methane on the way to think about that is that my my arrows represent the interaction of this film orbital here is non-binding lone-parent on oxygen we can represent that with the end with the subscript attacking an antibody mortal donating its electrons into the same Debenham orbital and therefore breaking the bond that would depict that interaction like this field orbital like this non-binding orbital on oxygen is interacting with an unfilled orbitals this Sigma star the model for the carbon chlorine bomb in Appendix 2 orbitals I have to get to orbitals out I film orbital that's lower in energy and an unfilled orbitals I creating new bond new oxygen carbon bonds representing like this by creating a lantern bonding orbital with that goes along with that new bond that we create OK so important aspects of this diagram that we said is
we said that whenever the energy difference here is small whenever nuclear files are high in energy and energetic whenever electric piles are low in energy and easy to
attack and easy to donate into that results in a small interaction a small difference in indoor orbitals of injury they're interacting and that results in a very big energy benefit you get a very big drops in energy for the new world religion fury and consequently your reactions will be exiled Thurmond and fast and that's what we care about we care about reactions that focus that's the NO interaction diagrams and 90 may not be experienced using those but sometimes I'm going to fall back on those to try to explain the energetic consequences of our aero pushing so let's continue talking about this idea that there's a way to depict things with them diagrams itself on about frontier orbitals and I want you to consider another S into reaction and kind of getting tired of these very simple reaction but we can but we have to start with the interdisciplinary want you to think about this idea that maybe ammonia could come close to Bromo methane
are maybe something would happen as they interact with each other and you can if you want to think about
the interaction of the pneumonia molecules with problem with saying we have a rule that we have to satisfy and that is that when 2 reactants approach all of the field orbital and those in 1 molecule will interact with all the and those in the other molecules and vise versa it's going to be this crazy crazy way to think about things if we really want to be accurate about what's happening to these 2 things approach we have to think not about just this we have to think about every orbital interacting let me show you what that means in terms of equations remember on the 1st day I said I'm going to give you an equation with 3 terms that involves electrostatics involves spirits and some sort of mysterious and interaction mathematical terms look like this and there's summation symbol in there this says you have to add up all the interactions for all the animals in order to accurately quantify this what that means I can't just think about this interaction with sickness .period here I also have to add up the energy I get by doing that the probe nation there and attacking them on in T-bond simultaneously this slowing very gets closer and closer it's also overlapping with that empty I also have to think about the electrons in CH bond coming back and attacking and doing a nation there's an bonding orbital it's empty there's a field orbital and you have to think about those interactions in you have to add up every single interaction it just gets crazy if you want to be accurate about them so interactions between field orbitals and prolonging the halved at all this stuff together and so let me use an MO interaction diagram to depict this asked to do as I want to take an access for energy and I wanted to pick 1 of
the reactants pneumonia and it's a whole series of filled and unfilled orbitals In a Garfield
orbitals for the ammonia and then unfilled orbitals and I'm not going to draw all of them we don't need all of them you can add up the electrons in the Lewis structure there fear how many feel levels I need some distance to go some of them and the the analyst for the for the other reacted the promo methane it's also going to have orbitals on better filled and unfilled I see bonds in Brohman fame therefore I must have some sort of bonding type baubles and some empty warbles so I'm not going to draw all of them I just wanna draw some of them so you can see how crazy this interaction diagram with me I have to think about the overlap of this for example non-binding orbital on nitrogen interacting with Sigma star for the carbon bromine bond but I also have to think about this interacting with every single other orbital simultaneously
hence the number of interactions is massive and we're not going to be any good us
now I come back to the form of this equation because there's something here that greatly simplifies alive and that is the fact that the interactions here are dependent on the difference in energy another word when I look at this I can tell that 1 of these orbitals is higher in energy and more nucleophilic than the others and because this energy differences in the numerator I will get less interaction energy if I take 1 of these lower energy warbles like this 1 down here and try interact with 1 of these higher energy None of the is energetic and as good as this and as a consequence of that we can ignore this and when I come over here and I look at the empty ovals none of these orbitals receded into as as this sickness .period the lowest energy unoccupied orbitals so we can ignore those and usually were going to be good at identifying which 1 cities most nucleophilic
in which 1 does not know which ones are not and so we're going to ignore these
as well we're going to end up because this is in the numerator and is only about all our overall quantity is only being when the 2 orbitals interact in directing a close energy we're going to be able to reduce every single interaction like this into the interaction of 1 field orbital and 1 month along and that's like this right here it greatly simplifies alive Kenny chief Fukui won the Nobel Prize in 1981 for recognizing that way the denominator is small this time expert that's the Nobel Prize the forefront your before you could have 1 that if you would recognize that the mathematical consequences of what that means Is it if were interested in the interaction of orbitals with unfilled orbitals them and we can approximate and say we don't have to be exact we just have to look at the orbital interaction which is the home
of 1 of them and we don't need to
think about all these other heroes just the end that matter most so that's what frontier orbitals molecular theory is all about frontier molecular orbital theory says on the principal terms just look at the home of the and so of it is right that down to remind you of it so I'm going to start using the term home 1 loan for the rest of the quarters at the time I made for him every once in a while from now on I'm going to refer to those as the frontier orbitals that the energy frontiers lowest energy and the orbital the highest energy from and what we're
going to refer to his frontier orbitals until you spend the rest of our time using pushing to indicate these interactions
with has most very powerful stuff you know seems very simple OK so it's going to take a look at at the canonical frontier waterfalls we care about and trying to convince you to care about the energies of these orbitals which orbitals are high energy which orbitals low-energy that our surrogate for asking which electrons are nucleophilic which electrons are not so nucleophilic which things are easy to attack in which things are not easy to attack Sony for the rest
of this quarter we're going to talk about 6 canonical
frontier molecular orbitals molecular orbitals can have bizarre shapes bizarre three-dimensional shapes spread out over entire molecules but when you look at the frontier orbitals in the shapes that they adopt there's only 6 basic shapes to those frontier orbitals and I'm going to let me try to give me the energetic consequences you I'm going to start up and run the word for example 1 copy roller empty that's like a cobbled Caroline on NTP orbital boring if I take to P orbital on carbon I can mix them together to get pipe bombs 1 will be lower in energy and 1 will be exactly the same amount hiring energy so warbles a field that the pipeline relatively that P orbital pie should be equally lower and price starchy side should be made banning work should be equally now if I take on another war 1 I mix it in with these in order to get a signal behind those of the lowest energy orbitals along the lowest energy field with all that I can also make sense of as character and get a non-binding wardrobe but he makes as character that's definitely lower energy in P word or those are things like S P 3 lone pairs S P 2 lone pairs lone pairs of the highest energy field rules that we will ever talk about 95 per cent of the time you you push heroes your 1st Aero will start with a lone pair a non-binding pair with a pair of electrons in 1 of the same type of and then the highest energy under laudable that we can talk about it will be a sickness tolerable she has never questioned the you have to work hard Tom because the other warbles have to hybridize noted above so in other words if I drop ammonia this has a certain hybridization because the nitrogen needed to use a certain type of hybridization of form bonds that it didn't born if it didn't formally bonds went in with anything else emissions the individual nitrogen atoms you're view hybridization is totally arbitrary it's only 1 startling start to form bonds with particular geometries that's when you can decide I was OK so what we have we got this a total of 6 types of orbital regards Reidville novels 3 types of unfilled orbitals these are canonical frontier orbitals and we are going to spend the rest of the quarter talking about the interaction of these 3 field or bills with these 3 and but only 9 possible combinations of basically covered the entire class for you right here on this diagram so hard at his feet and we will find out as it's immensely difficult content very very interesting but to tease apart reactions into these combinations so like I said we're really interested in how high and energy of warbles of how reacted this pair of electrons is in this orbital or how low in energy the same divine marvelous we care about what things make things higher managerial and energy recordals higher in energy in the world and so what I wanna do is understand the rest of this section on frontier molecular orbitals talking about How does electro negativity perturb the energies of these orbitals others bond length perturb the energies of also rules out as conjugation perturb the energies of the corals because if we can decide which molecular work over time energy we know where to start or on our air
cushion them so it's going to start to talk about those but it was will be going to
start up a tugboat elected negativity and we've already covered this I talked about in the context of atomic orbitals With the end of the year but so the funny on explain what I mean by this molecular orbital centers 1 more election negative Adams are lower in energy so for example but I try to imagine a lone parent carbon the multiples at the Ka-band I'll put a little minus there just to remind myself when compare budget in science if you wanted to draw that out you might draw something like this it doesn't matter whether it's
you go with fearsome Beuerlein iron or were not going to worry about what the AA group so that attached ,comma what would happen if I read pleased that carbon atoms With the nitrogen atoms with something more electoral negative as soon as I switch over to to a nitrogen atoms I now have 1 more Proton in the nucleus Nigerian has 1 more Proton nucleus if you were an electron you would want to be on the nitrogen orbital what you can expect it every single warble that involves the nitrogen and will now be lower in energy and that includes the non-binding warble on on nitrogen the lone-parent nitrogen you could already knew that nitrogen lone pairs or less nucleophilic unless sick incurred an iron-willed appears at the end a switched oxygen and have hydroxide or Alcock side and again let me be generic there I should
expect that to be less
nucleophilic and less energetic than the lone hair on nitrogen as I keep going more and more election negative all continue to see every single word involves that Adam dropped and so finally will get on the fluorine which has no bond powerful writing in Ireland there's nothing bonded to it and I should expect that to be the least nucleophilic at least energetic people so I'm really telling you stuff you already knew you had an intuition I'm sure before you walked into this class that fluoride ions are less nucleophilic and carbon mind you already knew this effective electronically and is trying to grapple for you in terms of molecular work so it's going compare arms talk about the impact on antibody mortals it was with that the the
food the thing about this from unimaginative nuclear attacking that .period it is phenomenal popped out some sort of a leading group on you like this 0 pushing probably very few while they're pushing itself a spot fine but as a reaction that doesn't look very plausible to you and what is that that's good sketch out what happens as we take a Sigma star warble like this carbon-carbon 1 and we Weagraff that what happens if I replaced this out of here with something else I'm interested in the empty bonding orbital here and overseas but some other at your
intuition already tells you what's going to happen to the cinema star orbital energy if I
replaced this carbon atom right here was something that's more lecturer negative like nitrogen that you might think that that and your durable is easier to get into ever replace that carbon atoms with an oxygen atom and become even more electoral negatives in the orbital energy is lower and it's easier to donate into them and finally we get to something like the Fleury an iron ore flooring group and now you're starting to get to the point where maybe you can imagine popping out before writing and you may have at all kinds of reasoning the rationales for why it's better with flooring at all 49 is more stable they no that's completely wrong the reason why you could potentially push out of fluoride but never a methyl is because the Cygnus told get lower in energy when you replace carbon with something that's more electronic has nothing
to do with the leading group and that someone dynamic aspect to the reaction so that's
why it's this effect electronic sing star that's why you can't do this but you can't do this and this is something of an extra something that's electoral focus so that the effect of a lecturer negativity did you knew this stuff already and we just didn't have some sort of ammo diagram picture for why that is true at the end of the month and so that the effect bond lengths on orbital energies on the energies of frontier workers and but it would be a good thing for me to do and we will be working with but but we don't
this could make a look at the effect of making bombs either longer or shorter in this case I look at the effect of making up on longer ,comma sketch out the frontier orbitals that I might associate with carbon fluorine by not just Sigma stalwart model for carbon foreign bond really high in energy and drop the signal bond really low in energy what was single next field missing always really high and what I wanted do that 1 or imagine if I look at the periodic table with sketch of the periodic table here the as I dropped down this role from Florene to chlorine to bromine and iodine what's happening as
dropped from from the 2nd row which chlorine to the 3rd row with chlorine is that Adams get
bigger and bonds get longer warbles interact less effectively when farther away when I go to low-carbon chlorine behind what will happen In try to distort this and make it look really long because that's the way I'd like you to remember that bond when I go along the bond the overlap between his carbon chlorine is poor and so I get a weaker bond and because the bonded as weaker it's easier to break this is the way to represent this graphically look at the effect of things being farther away poor overlap makes defines those weaker bonds we represent like this that means that that bond is more nuclear fuel if you ever have any reason to use the CIA bombs to attack something you can assume that the carbon glory bodily faster hesitantly about I'm not saying you ever do that that's totally sure but if you
had reason to you could make this comparison and as I keep dropping down the Periodic Table
2 larger and larger Adams like carbon bromine the bonds get weaker the electrons in that signal bonds become hiring energy and the bomb becomes easier to break and finally albeit to a Carbon II and bond this is Sigma star similar hadn't intended stars here start going start at him was the field mortals so Israel's bonding mortals that it's in intervening was the star nominee that local really long you get a sense I'm exaggerating how much of a differences in body like this but so this is the effective online this you go too long were longer bonds the bond itself becomes more nucleophilic but it also
becomes easier to break the bond sold you ever wondered why it's so popular in
organic chemistry to attack alkali decides it has nothing to do with leading group ability of you learn some rationale that I'd about you totally learned something was completely fictitious this is why it's easier to attack alkali died because the Cygnus store orbital flight ,comma 9 bond is lower energy because the bond is long and you can take this bond length and apply it to anything you want longer bonds more nucleophilic unless stable longer bonds are also easier to break the filets extend this week it the
former on the 2nd row Adam like carbon on carbon
nitrogen oxygen aluminum is a third-row out which of these do you think is more nucleophilic these bonds are longer the bonds are higher energy aluminum hydrate aboard the high hydride bonds are more nucleophilic found Wii way way way way way more nucleophilic you couldn't guess that just by looking at the fact that aluminum is in the 3rd row and 1 in the 2nd row so again for the same reason that alkali died easy are more reactive in Anelka fluorides these are better nucleophile This is a better and more reactive nucleophile Alou's right he held last month electrified could be accordingly if you've ever worked with sodium Morel hydride lithium aluminum hydride you already know that Tetra Hydra to illuminate unhcr and burst into flames when you expose it to
alcohol or to water and oral hydride which just all the react more slowly there are no
non-binding electrons in the Newton correctly drug Lewis structure that there were those of the atmosphere OK so it's good look at the effect of conjugation on on our canonical frontier orbitals unlike every amenity that you're going to find is very very quickly I'm not going to be drawing and diagrams anymore rather than a couple lectures you're not going to see him anymore but I expect you to be using them to think about structures that year were going to be drawn large very complex molecules on and this is the
kind of stuff you have to fall back on bond length lecture negativity issues like that but
with the with the the tools with which to work with the it was to so if you notice it with this when I do it out there was this pinching effectively as I went to longer bonds lumos got lowered energy home was the hiring manager so we're going to see the same effect as we had conjugation 2 molecules it was and what I want to do
is I want to try to sketch out the pi orbitals for if at the Merry go with this start
again the focus of the field laudable for this pipeline on there's a field orbital that's the pie bondage concede that 2nd bonds and then there's the into bonding pie Orbital ,comma now you don't see we don't draw those who control the structure and so what would happen if I conjugated double bonds to another system what would happen as I watched the film lower-middle get hiring energy and the unfilled orbitals get lower energy the and as I
keep increasing the conjugation of keeps seeing this effect on the increase I will get higher energy price target
on energy and this is all relative to appeal work along with the energy of just plain view beauty fact you can continue this on ad infinitum etc. indices into which the implication is that it's pretty profound this is just like making bombs longer this idea of pie conjugation we will that's going compare to molecules
the standard 19 1 of them is what 1 3 Penta dying and 1 of them is 1 for 29 and what I wanted to know
that when I think about these acting as nuclear files maybe if I had some sort of a cargo cat iron knocks the beginning of mine and I could imagine despite bond attacking the canoe new carbon-carbon we will talk about the effects of Prince reactions are electrical work aromatic substitution later which of these is faster conjugated or non conjugate still the conjugated wants faster the question is why How can you know that I think in some organic chemistry we tell you something stupid like always makes an al-Qa'eda and that's more stable that's not the reason why the reason like Costas over here when you add conjugation you raise the energy of the pilot from the harmonious apply electrons or higher energy these pilot programs that's why this after OK now let's look at I don't often call this the reverse it's almost the reverse of the let's think about something different but think about a nucleophile attacking the price system here so near the conjugated system reacts faster with Electra files but which of these should react
faster the nuclear file the conjugated or on conjugated the conjugated should react faster they both react faster nuclear files on electrical react faster with conjugated systems and again here in your introductory organic chemistry class you probably made up some idea like well it makes a more stable carbon that will help prevent hundreds of something that's just totally wrong that's not why nucleophile that faster nucleophile that faster because pie stories lowering energy when you that's the effective conjugation just like longer bonds and what's bizarre and it's not bizarre I don't you get stuck in this conundrum here I was there's 2 molecules that the same
molecular formula these 2 molecules the conjugated 1 is more stable conjugated molecules molecules with
conjugated by systems are more stable than comparable comparable molecules that have no conjugation how can it be that the more stable of these 2 molecules reacts faster with nuclear files and fast with electrified and it has to do with this diagram and where much of the year in my conjugate to pipelines together what I did not show you is that there's a bunch of other warbles there's other there's actually 2 different pine warbles other signal rules those get way lowered in energy when you conjugate the overall this whole molecule was more stable when it's conjugated in this 1 but I just look at the most reactive pair of electrons and that's all I care about the 0 pushing the most reactive pair of electrons disappear His hired energy even the
molecules of wealthy so it's possible to raise the homeowner energy even while you're
lowering all the other orbitals really lower don't confuse this pair of electrons that I'm showing that might with my error with the overall stability of the molecule that the 2 completely different things these 2 electrons can become more reactive even tho the overall knowledge is more stable I need settlement OK so and that's all we had to say about orbitals today and we still have sometimes willing to go to the next topic on but again I handed out a summary sheet for you that summarizes the effects of things like Elektra negativity on orbital energies from him if those cheaters standing around composite things like P. character on moral energy seems like bond length and orbital energies effects of conjugation and I expect you to be using his new brought structures it enjoyed a steroid or an alkaloid assembling in healing you can extend these these very simple concepts to very complex molecules that nobody in the remaining time remained start in the next topics and that's going to be a discussion of energy this it was in the
lead in the yes I was worried about that you have been in use the black pants it would have to pay for it In the past the theory goes OK so far it gives equation I think all of your familiar with this kind of antiquated learned on the freshman chemistry gene can be learned in organic chemistry and then you never use it again and I want to boil this idea down something very simple and when it "quotation mark the the summit to imagine knowing somebody some money it was the height of the city rather go to somebody not obvious it's totally not obvious I I don't feel like it's obvious to me I'm a pretty clever person but the men putting some gas in your tank army leaders of does it take to fill your tank or even a vise gallons the matter whether Afghan doesn't matter whether it's because the leaders you have no idea the kids if you sat long enough you could think of making Is it logarithms excellent are not intuitive they're not into it did not intuitive to you they're not intuitive to me they're not intuitive anybody but maybe a matching a genius like remind agenda it's it's not helpful for us to use numbers like this and this is the problem with this equation that fundamentally the problem so I'm going to ask you to not think like this because it's not into it so let's talk about what is intuitive and going to encourage you to convert free energies into things that are intuitive for the rest of your time is an organic chemist and ask you to do this but this is the 1st of the the
ratios are intuitive and more importantly base 10 ratios are intuitive to use the intuitive to use to me they are intuitive to my four-year-old daughter she can tell the difference between 1 and 10 and which is more than someone a daughter a table for you I want to think about this so it doesn't matter what the actual molecules are any set of reactants and products where we think about an equilibrium and I want to think about the impact of putting numbers energies into this equation over here that involves either natural logs of experiments and what I want to do is I want to try to equate energies with numerical ratios so all the means to make the table so well dissolved or some sort of a delta G value and and dropped the ratio of 8 to be whenever you have a free energy difference of some number 4 train starting materials and products or between 2
transition states doesn't matter been so I'm going to stop in the middle of this table when delta G is 0 free energy differences 0 what's the ratio of those 2
species at equilibrium when the free energy differences 0 one-to-one and I have a very clear idea what 1 means my daughter has a clear idea what one-to-one meetings it's very easy to grasp is that what's important is what happens is a increases ADB ratio from 1 to 10 I want you to know what the free energy differences it turns out that free energy difference is 1 . 4 K calls from all favors the product in this case I'm going to put a negative sign there I had no idea what how to think about 1 . 4 K comes from all but I know how to think about 10 to 1 I know 10 is bigger than 1 and I know 10 is a lot bigger than 1 foot powerful here is the free energy differences minus 2 . 8 K Kallstrom all but the energy difference is now
1 to 100 and you get the trendiest sign now expect you to know that trend what happens if the at it if the equilibrium difference here is 1 2 with thousands once the free energy difference
minus 4 . 2 I usually can't even remember the . 2 unlike of minus-4 for political before coming to hear start using giggles from all this class I always used of American cake held from all instead of conducting OK so every time from now on that I give you an energy difference whether it's in energy demand the starting materials and reactants whether it's an energy difference between 2 transition states I expect you to convert that into a set of ratios in your mind because ratios are into it all this transition state is 1 . 4 K calls from all over an energy this 1 that lead that's 10 times faster that's into its forte Kallstrom all it's about a thousand times faster if the energy of a three-story products is a thousand the 1 you have a chance of getting over 99 . 9 per cent yield on reaction because the equilibrium will favor product react a meeting the other direction is as well as the energy differences positive 1 . 40 Kallstrom all now goes the other way 10 to 1 in favor of starting materials you don't have a prayer of getting a good deal of their reaction nothing you do can change that in difference and if I had another four-point Kate tells to 124 giggles from all too that's a penalty this amount now that's really it is favored reaction by 101 and you can keep food so I expect you to know that 1 . 4 K felt is a factor in him now I expected or tied at so free energies are only useful to the extent that you can convert them to ratios I expect you to be very fast with this 1 . 4 K Kallstrom OK let me give you 1
more energy per 1 more sort of all that on that the 1st by writing up the 1 . 4 4 and it was 1 of
the conditions so 124 K Kallstrom always equal to a factor of 10 by the equilibrium constant warrant a rate constant yes at 298 so and I think on the problems that I ask you to do something version that the temperature OK but much of it described as a policy expert who once you're really good at 1 . 4 2 really good applying this in his duties factors that cannot give you another really in the this is a good thing because this but that is a 0 .
4 K Kallstrom was a factor of 2 this is the only ones I really remember so by I energy difference in transition states that's only point for from all all this
transition status .period for takeout from all in energy lowered let me that's twice as fast I'm not really good with . 4 so when I see 25 cyclists about a factor of 2 it's kind of a level at which I think the lesson some chance to practice with on on the problems OK so as good armed talk about some real examples of this without the use of that people but the the vote if you're drawing the centerpiece of paper I advise you just to draw the cycle Augusta the lack tone waiting there that's all we really care about it for right now this turns out to be clinically use drugs what you and there's
substantial sum substituent I never that doesn't matter in what I want you to think about is the reaction of this with water so if you wanted a higher July this open it was with which it was but it was with this book with the this was In order to get this hydroxy acid but what kind of deal can you expect for this reaction I can tell you right now that the free energy change is this and why would you wanna idolize it turns out that if you don't it's not soluble is very forcefully he can't administer this this particular derivative of the right of the
cancer drug what field very low it's very lovely
and equilibrium the ratio is going to be a thousand and 1 that's 3 factors of 1 . 4 it's uphill by 4 . 2 K Kallstrom the whole you have no chance of doing this and that there is a way to to hide realize this but you have to do is not use acid you do it base so that this site is not a wage at the carboxyl late and then it becomes the modern manically favorable that's would be administering the drugs in order to get solubility of so and you can't get better than 0 . 1 per cent yield if you're trying to isolate the Free Aceh the wouldn't extend this idea that take calls from all give us useful useful ratios up to transition states but if we will this is the 1st president of the state this is 1 of the most that's suppose you do a lithium aluminum hydride reduction on this issue and you get a 95 percent yield of the axial alcohol and engaged it's not obvious there's the hydride group that I just added this is what you get after work on this to possible transition states where this anyone transition state hydride ads from the top and the
other traditions state the hydride ads from the bottom to give you this product right here and so
what's the difference in energy for those 2 transition states for axial attacked Brazil Equatorial attack you can imagine a starting job going there 1 transition state are the other transition state and the only thing you have propped perhaps is Teal c plates for some sort of isolated he'll have to convert this into transition state free energy what's the maximum amount of the other isomers that could have been obtained in this reaction 5 cent you already knows to number the fact that 2 numbers I can make a radio that that means the ratio is at least 20 to 1 right I don't know how much of the mine Remedios was 1 person but I know was at least 20 to 1 might be greater and so what does that mean it's a factor of 2 it's a factor of 10 2 1 how much energy for a factor of 10 1 . 4 K Kallstrom all or tiny how much energy for a factor of 2 or 0 . 4 K cows all that means I know that the energy difference between this on favored axial attacked and the favorite Equatorial attacker is at least I don't know how much greater the 1 . the 2nd give people a meaningful number so every single time you look at it heals see plays a
lot of books about twice as big or you get a yield musical about 60 per cent of this isomer I didn't get 40 per cent of the others you can create ratios and when you can create ratios you can create free energy differences and it doesn't matter
whether it's transition states or equilibrium values between starting to end product and I encourage you to do that but they were going to come back and finish up these ideas about how we use energy use energy and I want you to practice his 1 . 4 the Kallstrom from all its immensely useful right when you're discussing things with other tenants in these numbers like this it's not as powerful as when you use numbers like that
Single electron transfer
Konjugation <Biologie>
Chemische Bindung
Hybridisierung <Chemie>
Fülle <Speise>
Elektron <Legierung>
Chemische Reaktion
Bukett <Wein>
Organischer Halbleiter
Funktionelle Gruppe
Aktives Zentrum
Setzen <Verfahrenstechnik>
Oxoglutarsäure <2->
Chemische Formel
Matrix <Biologie>
Setzen <Verfahrenstechnik>
Internationaler Freiname
Spezies <Chemie>
Organische Verbindungen
Monomolekulare Reaktion
Elektrostatische Wechselwirkung
Chemische Forschung
Chemische Forschung
Chemische Struktur
Systemische Therapie <Pharmakologie>
Einsames Elektronenpaar
Potenz <Homöopathie>
Chemischer Prozess


Formale Metadaten

Titel Lecture 02. Molecular Orbital Theory (Pt. 2) & Energy.
Serientitel Chem 201: Organic Reaction Mechanisms I
Teil 04
Anzahl der Teile 26
Autor Vranken, David Van
Lizenz CC-Namensnennung - Weitergabe unter gleichen Bedingungen 3.0 Unported:
Sie dürfen das Werk bzw. den Inhalt zu jedem legalen und nicht-kommerziellen Zweck nutzen, verändern und in unveränderter oder veränderter Form vervielfältigen, verbreiten und öffentlich zugänglich machen, sofern Sie den Namen des Autors/Rechteinhabers in der von ihm festgelegten Weise nennen und das Werk bzw. diesen Inhalt auch in veränderter Form nur unter den Bedingungen dieser Lizenz weitergeben.
DOI 10.5446/19218
Herausgeber University of California Irvine (UCI)
Erscheinungsjahr 2012
Sprache Englisch

Inhaltliche Metadaten

Fachgebiet Chemie
Abstract UCI Chem 201 Organic Reaction Mechanisms I (Fall 2012) Lec 02. Organic Reaction Mechanism -- Molecular Orbital Theory (Part 2) & Energy -- Part 1 Advanced treatment of basic mechanistic principles of modern organic chemistry. Topics include molecular orbital theory, orbital symmetry control of organic reactions, aromaticity, carbonium ion chemistry, free radical chemistry, the chemistry of carbenes and carbanions, photochemistry, electrophilic substitutions, aromatic chemistry.

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