Nitrogen forming two bonds

Two bonds formed by a N atom having one or two lone pairs would be expected to be angular with bond angles of 120 (one lone pair, sp bonds) or 109 (two lone pairs, sp bonds). (Molecules such as diazirine (cyclic diazomethane) and perfluorodiazirine are special cases like cyclopropane or ethylene oxide.) If the 

Among the later demonstrations of this bond arrangement are the crystallographic studies of cis and trans azobenzene (ii) and of dimethylglyoxime. The configuration of the latter molecule changes from the trans form (a) in which it exists in the crystalline dioxime to the cis form (b) when it forms the well known Ni, Pd, and Cu derivatives. 

The simplest compound of the type RN=NR, di-imide, has been identified in the mass spectrometer among the solid products of decomposition of N2H4 by an electrodeless electrical discharge at 85°K. Both isomers have been identified (i.r.) in inert matrices at low temperatures (as also has imidogen, NH ), and the structure (a) has been assigned to the cis (planar) isomer 

Difluorodiazine, N2F2, is a colourless gas stable at ordinary temperatures and is prepared by the action of an electric discharge on a stream of NF3 in the presence of Hg vapour or, with less risk of explosion, by the action of KOH on N,N-difluorourea. The isomer F2NN is not known, but the two isomers FNNF have been separated by gas chromatography, the cis isomer, (b), being the more reactive/ The structure of the trans isomer,(c), which may be prepared in 45 per cent yield from N2F4 and AICI3, is similar to that of azomethane, (d). 

The crystalline compound of CK-N2F2 and AsFs is soluble (and stable) in anhydrous HF. Itisisostructuralwith(N02)AsF6 and is presumably (N2FXAsF5) containing the linear N2F ion which is isoelectronic with NOj- 

---