Bond length

[AA|FCB|DOC]

I just wanted to make sure I understand all the parameters that bond length is affected by. I know for sure the hybridization of the atoms has an effect (more s character means shorther bond), and I also know that the size of the atoms nuclei play a role too since a bigger atom will not be able to share electrons as closely and thus will lead to longer bonds. Does electronegativity play a role on bond length as well? Thanks in advance

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[sdm33]

Resonance plays a role on the length of bonds, for example if you a have a carbonyl next to a N with a lone pair donor to make the carbonyl double bond resonate to a partial double bond which is smaller than double bond but bigger than a single bond.
Also Inductive Effect For example if you have a high electronegative atom F > O > N > Cl > Br > I , they can delocalizate electrons through the sigma bound.
They can also increase or decrease acidity depending of how close they are the double bond.

 

[AA|FCB|DOC]

Thanks for the reply. Just to make sure on the inductive effect, so if something is more electronegative then will it cause the bond to be shorter or longer?

 

[gwjib04]

In the BR GC1 section on Acids and Bases they say that the bonds of Haloacids get longer as you descend a column because the atomic radius is increasing not because of Electronegativity.

In the same book but in the Atomic Theory section, the authors rule out a bad response stating:
"bond length dictates bond strength but not necessarily relative electronegativity"

Makes me think bond length is not affected by EN, just the electron density which I guess isn't the same thing?


This area has confused me too because BR says haloacids get more acidic as 1. the halogen gets bigger and 2. less EN atoms can stabilize the negative charge of being a conjugate base better therefore are also more acidic.

But then oxyacids are more acidic as the central atom increases in electronegativity. The mention that the resonance effect is more important for determining acidity of an oxyacid so # of oxygens is more important than EN.