Suppose that the ion is excited by light, so that an electron moves from a lower-energy to a higher-energy molecular orbital. wo

Question

nydimaria [60]

3 years ago

14

Suppose that the ion is excited by light, so that an electron moves from a lower-energy to a higher-energy molecular orbital. wo

uld you expect the excited-state h−2 ion to be stable?

Chemistry

1 answer:

yawa3891 [41] · Answer 1 · 2022-07-17T08:33:42+03:00

<span>As can be seen from the 1st MO diagram on the website the overlap of the H1s AO on one H atom with the H1s AO on another H atom results in a Ď MO at lower energy to the constituent AOs, and a Ď* MO at higher energy than the starting AOs. Each MO can hold two eâ»s so the H2^- has the configuration Ď(2eâ») Ď*(1eâ») or Ď(â†‘â†“) Ď*(â†‘) Bond Order = Â˝[ÎŁ (bonding eâ») - ÎŁ (antibonding eâ»)] bo = Â˝[ÎŁ (2eâ») - ÎŁ (1 eâ»)] = 0.5 the H2^- is predicted to be bound. The lowest energy electronic transition is Ď â†’ Ď*: Ď(â†‘â†“) Ď*(â†‘) â†’ hÎ˝ â†’ Ď((â†‘)) Ď*(â†‘â†“) This guy has a bond order of -0.5 and hence is unbound.</span>