Hyponitrous acid, isomers

Nitramide. N02NH2, a weak acid (pK. = 6.59), is relatively more stable than its isomer hyponitrous acid,... 

Spectroscopic data indicate that hyponitrous acid, HON=NOH, has the planar trans configuration. Its structural isomer nitramide, H2N-NO2, is a weak acid. The structure of nitramide is shown in Fig. 15.2.2(a) in this molecule, the angle between the NNO2 plane and the H2N plane is 52°. Both trans and cis forms of the hyponitrite ion, (ONNO)2-, are known. The trans isomer, as illustrated in Fig. 15.2.3(a), is the stable form with considerable n bonding over the molecular skeleton in the cis isomer, the N=N and N-O bond lengths are 120 and 140 pm, respectively. 

The hydroxygroups of hyponitrous acid are found in a trans (73) and a cis (74) conformation (Scheme 29). The nitridonitrate isomer (75) is only known in form of its tautomer, nitramide. 

Nitramide (87) is a structural isomer of hyponitrous acid HON=NOH (H2N2O2) (Figure 12). 

SCF calculations have been carried out on the molecule HNO ( nitrosyl hydride ) and its isomer HON ( nitrogen hydroxide ). " The system is found to have a low-lying triplet state, which is expected to aid in the dimerization to hyponitrous acid, H2O2N2. 

There is a compound called nitramide, which is also a weak acid (AT25. = 2.6 xl(T7) and is an isomer of hyponitrous acid, Its structure has been shown to be (12-XI). 

The reaction of acid with potassium nitrocarbamate results in the formation of nitramide (equation 15.107) which is an isomer of hyponitrous acid. Nitramide has been structurally characterized one N atom is trigonal planar (O2AN) and the other is trigonal pyramidal (H2AN)- The compound is potentially explosive, and undergoes base-catalysed decomposition to N2O and H2O. 

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