Nitrogen-oxygen bonds bond lengths

Since they are identical and contribute equally, there is only one type of nitrogen-oxygen bond, intermediate between double and single in length. 

Although the two oxygen atoms in nitromethane appear different in Lewis structures, experiments show that they are equivalent. Both nitrogen-oxygen bonds, for example, are 122 pm in length, midway between the length of a typical N-0 single bond (130 pm) and a typical N=0 double bond (116 pm). In other words, neither of the two Lewis structures for nitromethane is correct by itself the true structure is intermediate between the two. 

Draw Lewis diagrams for the two resonance forms of the nitrite ion, NO2. In what range do you expect the nitrogen-oxygen bond length to fall Hint Use Table 3.6.)... 

Fig. 2. The calculated [D-MBPT(4)] potential energy curves for the three lowest electronic states of nitrosyl hydride. For each choice of R j shown, the bond angle and nitrogen-oxygen bond length were optimized for each of the states.

Experimental studies support our conclusion about the resonance structures of NNO. As we describe in Section 9-1. double bonds are shorter than single bonds. The length of the nitrogen-oxygen bond in NNO is less than typical N—O single bonds but greater than typical NDO double bonds. 

The bond lengths between tin(II) and atoms with lone electron pairs like nitrogen or oxygen are quite small (200 and 209 pm compared with 208 and 215 pm as expected (see Chapter 3)) suggesting intramolecular electron compensation of the Ji-type ... 

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