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And so this lower level is called a bonding orbital, and it is a bonding molecular orbital.
所以能级较低的轨道叫做成键轨道，这就是成键分子轨道。
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So what we can actually directly compare is the dissociation energy or the bond strength of nitrogen versus hydrogen.
因此实际上我们可以直接进行比较,对氮分子与氢分子的离解能,或键的强度。
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The center of excess negative charge on all of the dipoles is at the very center of the molecule.
多出来的键,的负电荷中心都集中在,分子的正中间。
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The IgM is really five IgG-type molecules that are linked together through disulfide bonds, such that their FC portions are all pointing in and their antibody binding portions are all pointing out.
gM是由五个IgG分子组成的,IgG分子之间通过二硫键连接,免疫球蛋白尾部的FC片段都指向内侧,而抗体的抗原结合位点都指向外侧
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And you can go ahead and tell me what you think the bond order is going to be for this molecule.
你们告诉我你觉得,这个分子的键序应该是怎样的。
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You might have thought before we started talking about molecular orbital theory that non-bonding was the opposite of bonding, it's not, anti-bonding is the opposite of bonding, and anti-bonding is not non-bonding.
你也许在我们讨论分子轨道之前,就想过非成键时成键的反面，它不是，反键才是成键的反面，反键不是非成键。
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And this one here, because it is at a higher energy is called antibonding molecular orbital.
这里的这个，因为处在一个较高的能级,被叫做反键分子轨道能级。
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It's also important, once we start talking about molecules, to have a way to represent them, and also to be able to look at a shorthand notation for a certain molecule and understand what the bond is.
还有很重要一点是，一旦我们开始讨论分子，我们需要有一种表示它们的方法，而且能够从中看出,某些分子的简化符号，并得知键的类型。
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And the reason we didn't do that is because we're actually going to spend much of the rest of the course relating these different properties to the properties of molecules in terms of bonding, and also in terms of chemical reactions.
我们至今没有这样做的原因是,实际上我们这门课程以后的大部分时间都将花在,如何将这些性质与分子的性质联系起来,在成键以及化学反应的方面。
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I want to finish this discussion by including the anti-bonding orbital, and this is a tip for you when you're drawing your molecular orbital diagrams, any time you draw a bonding orbital, there is also an anti-bonding orbital that exists.
我想要以包含反键轨道,来结束这个讨论，告诉你们一个,画分子轨道图的小技巧，任何时候你画一个成键轨道，都会存在一个反键轨道。
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So we're going to finish talking about molecular orbital theory, we'll switch over to discussing bonding in larger molecules, even larger than diatomic, so we'll move on to talking about valence bond theory and hybridization.
我们要结束关于分子轨道理论的讨论，转向讨论大分子的成键，比二原子分子更大的分子，我们会继续讨论价电子成键理论,和杂化。
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This is sigma star with the antibonding orbital that came from 1s, and it is a molecular orbital.
这是sigma星，来自于1s的反键轨道,它是一个分子轨道。
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So far we've exclusively been using Lewis structures any time we've tried to describe bonding within molecules.
目前为止任何时候我们尝试要,描述分子内的成键,我们都是利用Lewis结构。
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So, we'll start today talking about the two kinds of molecular orbitals, we can talk about bonding or anti-bonding orbitals.
今天我们先来,讨论两种分子轨道，我们要讨论成键和反键轨道。
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we know that h is always terminal, right after the molecule that it's attached to.
我们知道氢原子永远都在末端，放到和它成键的分子的后面。
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He needs to know about the structures of the molecules, because if the structure is wrong it's not going to work.
他想要让它们成键，他需要知道分子结构，因为如果结构不对。
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So specifically, what we do associate them instead is within molecular orbitals, and what we say is that they can be either in bonding or anti-bonding orbitals.
特别的，我们把它们和,分子轨道相联系起来，我们说它们可以成为,成键轨道或者反键轨道。
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However, on Friday we will use a different approach so we can talkabout bonding within atoms that have more than two atoms, molecules with more than two atoms.
但是，在周五我们,会用一种新的办法来讨论,不止两个原子的分子的成键。
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So if we name this orbital, this is an anti-bonding molecular orbital So we had bonding and now we're talking about anti-bonding.
这是反键分子轨道,我们有了成键，现在我们讨论反键。
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We're already using it up in this pi bond here, so that means we're limited to only two other spots on the molecule, so we have three.
我们已经把它用到这个π键里去了，所以这意味着,我们在分子里只剩下两个位置，所以一共是三个。
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Molecular orbital theory, even at this very basic level, allowed us to predict that no, we're not going to see a true bond here, a strong bond.
即使在最基础的层次，分子轨道理论预计，我们不会看到一个键，一个强的键，。
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Then we're going to actually use MO theory to describe bonding within these molecules, and we'll start with homonuclear diatomic molecules.
然后我们要利用MO理论,来描述这些分子内的成键，我们要讨论同核双原子分子。
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So, let's change our graph where we now have this zero point set as the two individuals hydrogen atoms, and then we see that our h 2 molecule is at the negative of the dissociation energy, or the negative what that bond strength is.
那么让我们把曲线图中的零点能改到,两个分离的氢原子处，那我们就会看到,氢分子就是负的离解能，或者负的键的强度。
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So that's the idea of a bonding molecular orbital.
这就是成键分子轨道的概念。
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So if you're trying to make a more complicated organic molecule carbon-carbon bonds are one of the most difficult things to make in organic chemistry, and it turns out that c n minus is a very reactive molecule, so it's a good way, even though we'll go over some drawbacks in a second, it is a good way to make carbon-carbon bonds.
如果你要合成一个更复杂的有机分子,碳碳键是有机化学中,最难制造的键之一，而实际上氰离子是一种具有很高活性的分子，用它是一个好办法，尽管我们一会儿将看到它的一些缺点，但它的确是一个制造碳碳键的好方法。
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So that's going to be the end of the exam 1 material, and then we'll move on to exam 2 material, which is kind of exciting, because we've been talking about just individual atoms and ions up to this point, and now we can talk about molecules, so we're going to start talking about bonding.
到此为止就是第一次考试的内容，接下来我们会开始讲第二次考试的内容，这些内容令人有点兴奋，因为我们一直都只是在讨论单个的原子,和离子到目前为止，而现在我们可以讨论分子了，要开始讨论成键的问题了。
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So for some you that are less interested in maybe the physical structure of an individual atom, now some more exciting material for you might be coming up if you like to think about how, instead, molecules behave, either within bonding, within themselves, or with other molecules, that's what we're going to be heading to in this next unit.
那么对于某些同学，你们或许不感兴趣,对于单个原子的物理结构，现在可能有令你感到兴奋的内容,要出现了，如果你更喜欢思考,分子的行为，或者是关于成键的，或者是关于它们本身的，又或者与其它分子之间的行为，这些将是我们下个单元要讲的内容。
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N 2 So any chemist should be able to just look at n 2 and know that it's a triple bond, but that's not something that we've learned how did to do yet, so let's go ahead and start a new topic that's going to allow us to have some sort of sense of what the valence electron configuration, which includes whether something's a single or double or a triple bond can be figured out for any given molecule.
任何一个化学家都应该能够仅仅通过看到2,就知道它有一个三键,但是我们还没学习如何做到这点，因此下面我们就开始进入一个新的主题,它将使我们能够有一定的认识,对于价电子的排布情况，包括可以对任何一个给定分子中的键是单键双键,还是三键作出判断。
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So, if we think about what bonds are in this molecule, sp2 we actually have six of these sigma carbon s p 2, carbon s p 2 bonds.
如果我们考虑这个分子里都有什么键，我们有六个sigma碳，碳sp2键。
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And this will be called pi of 2py molecular orbital.
我们会称它为2py分子轨道上的π键。
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