Both of these lobes together constitute a pi bond.

上下两片叶一起组成了一根 π 键。

youdao

So we can kind of flip it this way this will be one pi bond, this will be another interacting between these p orbitals.

我们可以把它这样翻一下,这是一个π键，这是另外一个p轨道之间,相互作用的π键。

youdao

So it already should make sense why we have that p orbital there, in order to form a pi bond, we're going to need a p orbital.

这里有p轨道是很合理的,为什么我们在这里有P轨道，为了形成一个π键，我们需要一个p轨道。

youdao

And so both of these lobes together constitute a pi bond.

上下两片叶一起组成了一根π键。

麻省理工公开课 - 固态化学导论课程节选

So in order to rotate a double bond, you have to actually break the pi bond, so essentially what you're doing is breaking the double bond.

为了能够旋转双键，你必须打破一个π键，本质上我们要做的就是打破双键。

麻省理工公开课 - 化学原理课程节选

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。

麻省理工公开课 - 化学原理课程节选