Question

why is O-F bond length much shorter in OF2 (141pm) than in O2F2(158pm)?
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Answer 1

O-F bond length is much shorter in OF2 as compared to O2F2 because of the following reason:

• The explanation will be based on orbital overlap.

1. In $O_{2}F_{2}$ , there is presence of O-O bond. Since similar atoms are forming the bonds , the orbital overlap is very high. As a result ,the O-O bond length is short. On the other hand , the orbital overlap is deficient in between O-F bond. Hence the bond length is longer (approx. 158 pm)

2. But in $OF_{2}$, there is no such peroxide linkage. Hence the O-F bond has higher orbital overlap as compared to the previous molecule. Hence its O-F bond length is smaller (approx. 141 pm).