All right. So, let's go ahead and draw our Lewis structure here with sulfur in the middle.

好，那么，让我们来把我们的,路易斯结构画在这，硫在中间。

麻省理工公开课 - 化学原理课程节选

But what I'm going to tell you already is this is a case where, in fact, it's an exception to the idea that the lowest energy structure has the lowest ionization energy in the middle, and we can figure this out when we look at formal charge.

但是我已经告诉大家这个例子，实际上，是中心原子电离能最低的结构,的能量最低这一思路的一个例外，我们可以通过形式电荷看出这一点。

麻省理工公开课 - 化学原理课程节选

If we look at our last structure here where we have nitrogen the middle, we can also figure out all those formal charges, and in this case we have plus 1 on the nitrogen, we have minus 2 on the carbon, and then we end up with a 0 on the sulfur there.

如果我们来看看最后一个结构,在中间的原子是氮，我们同样可以计算出所有的形式电荷，而在这种情况下，氮为正一，碳为负二，而最后硫为零。

麻省理工公开课 - 化学原理课程节选

Often a good thing to start with is to put the lowest ionization energy atom in the middle, and if you don't have charge separation then go with that structure, but if you do find you have a lot of separation, such as the case in negative 2, positive 2, and minus 1, then you want to say wait a second, this is really bad in terms of formal charge, let me go ahead and see what other options I have here.

通常一开始把电离能最低的原子,放在中心位置就很好了，如果你发现电荷没有分开,那么这个结构就没问题了，但是如果你发现有很多分开的电荷，比如这种情况，有负二，正二和负一，那么你会想要说等一下，从形式电荷来看这很不好，让我去看看其它可能的选择。

麻省理工公开课 - 化学原理课程节选