Remember this is our bond axis here, and you can see there is this area where the wave function is equal to zero all along that plane, that's a nodal plane.
记住这是我们的键轴,你可以看到在这些区域,波函数在这个面内全都是零,这是节点面。
So, let me get a little bit more specific about what we mean by nodal plane and where the idea of nodal plane comes from, and nodal planes arise from any place you have angular nodes.
关于节面的意义,或者节面概念的起源,让我们讲的更具体一点,节面起源于角向节点。
And just to give you a sense, if you do a cross-cut of this, you cannot show it from this angle, but it should really be sort of a dumbbell shape with the nodal plane in between the two nuclei.
告诉你们这些就是给你们点概念,假如你们把他横切切开,不能从角度上展示,但它还是会保留几分哑铃的形态,以及在两核之间的节面。
So even though we see a nodal plane down the center, I just want to really point out that it's only when we have a nodal plane in the internuclear or the bond axis that we're calling that a pi orbital.
虽然在中间有个节面,我想要指出的是,只有节面在核间轴,或者键轴上时,我们才叫它π轨道。
Similarly, if we were to look at the radial probability distributions, what we would find is that there's an identical nodal structure.
相似地如果我们看看,径向概率分布,我们会发现有一个完全相同的波节结构。
The reason that I wanted to point out this nodal plane here is because this is why it is called a pi orbital.
我指出这个节面的原因是因为,它就是为什么这个叫做π轨道的原因。
So instead, these would be canceling out wave functions between the two, so we would end up with a nodal plane down the center.
相反,两者之间的,波函数会相互抵消,所以我们在中间会得到一个节面。
And so it has what? In contrast to the sigma, it has a nodal plane containing both nuclei.
这是什么,和sigma相反,它是包覆在核上的平面电子云,有一个界面。
They're pretty straight forward to do and it gives us an idea what kind of nodal structure we can expect it an orbital.
这个对我们来说很明显,而且让我们对,预计是哪类节点有个概念。
Pi orbitals are a molecular orbital that have a nodal plane through the bond axis.
轨道是沿着键轴,有节面的分子轨道。
And when we look at this, it's actually split by what's called a nodal plane, which is pointed out in light orange here on this picture, but what we just mean is that there is this whole plane that separates the two lobes where there is absolutely no electron density.
我们来看这里,实际上它被一个节面分开,在这图里用淡黄色表示,这意味着这个分开,两个叶瓣的平面上,是完全没有电子密度的。
What is the nodal plane in this case?
这种情况下的节面在哪呢?
What would the nodal plane be?
它会在哪?
So pi bonds have electron density both above and below the bond axis, but they actually have a nodal plane at this z, this bond axis here.
键在键轴之上,和之下都有电子密度,但它们在z方向有节面,这是键轴的地方。
And the nodal plane's going to be in the x z plane, or again, anywhere where phi is going to be equal to 0, that takes us to the x z plane.
节面是xz平面,又或者说是phi等于0的地方,这就是xz面。
The reason that it's sigma is if you look at the bonding axis here, is that there is no nodal plane along the bonding axis.
它是sigma键的原因是,因为如果你看键轴,上面是没有节面的。
Um-hmm. So, it's going to be the y z nodal plane, or in other words, we can say it's any place where phi is equal to 90 degrees.
嗯,是yz平面,换句话说,是在phi等于90度的面。
But in sigma orbitals, you have no nodal planes along the bond axis, so if we had a nodal plane here, we'd see an area where the wave function was equal to zero.
但在sigma轨道里,沿着轴向是没有节点平面的,如果我们有个节点,我们就会看到某个地方波函数等于0。
But keep in mind sigma orbitals have no nodal planes along the bond axis.
但记住sigma轨道沿着,键轴方向是没有节点的。
So again, we can name these molecular orbitals and these we're going to call also to point out there is now a bond axis along this nodal plane, which is something we didn't see before when we were combining the s orbitals.
同样的,我们可以,命名这些分子轨道,这些轨道叫做-同样要指出的是,现在沿着键轴是一个节点面,这是我们讨论s轨道的时候,从没有看到过的。
pxa So what happens when we add a 2 p a and we subtract from it a 2 p x b, or the same with a 2 p y a subtracting a 2 p y b, is that we're actually going to cancel out the wave function in the center, so we now have 2 nodal planes.
当我们用,减去2pxb时,或者是2pya减去2pyb时,我们会消去,中间的波函数,所以现在我们有两个节面。
应用推荐