The oxygen chemistry of nitrogen

Nitrous oxide, N2O. This molecule is linear and its electric dipole moment is close to zero (017 D). Because of the similar scattering powers of N and 0 it is not possible to distinguish by electron diffraction between the alternatives NNO and NON, but the former is supported by spectroscopic data. X-ray diffraction data 

NNO molecules are randomly oriented. This disorder would account for the residual entropy of lT4e.u. which is close to the theoretical value (2 In 2 = 1-377 e.u.). The central N atom may be described as forming two sp bonds the additional rt-bonding giving total bond orders of approximately 2-5 (N =N) and 1-5 (N-- 0) corresponding to the bond lengths 1-126 and 1-186 and force constants 17-88 and 11-39 respectively. 

Nitrogen dioxide, NO2. This is also an odd-electron molecule, and some of its reactions resemble those of a free radical, for example, its dimerization, its power of removing hydrogen from saturated hydrocarbons, and its addition reactions with unsaturated and aromatic hydrocarbons. A microwave study gives N—O, 1-197 A and the 0—N—O angle, 134° 15, in agreement with the results of earlier electron diffraction and infrared studies. 

Dinitrogen trioxide, N2O3. Pure N2O3 cannot be isolated in the gaseous state since it exists in equilibrium with its dissociation products NO and NO2. However, its m.w. spectrum has been studied at -78°C and 0-1 mm pressure and indicates the planar structure shown. Some of the numerous suggestions as to the nature of the extraordinarily long N-N bond are discussed in ref. (9). The structure of crystalline N2O3 (at -115°C) proved too complex to analyse.  

Dinitrogen tetroxide, N2O4. The chemistry of this oxide, the dimer of the dioxide, is most interesting, for the molecule can apparently dissociate in three different ways. Thermal dissociation takes place according to the equation 

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