Thionitrites metal complexes

Sulfurdiimines RN=S=NR and thionitrites RN=S=0 (R = alkyl, aryl) have been relatively little investigated as ligands in metal complexes. This lack of attention has been little deserved as both types of ligands have interesting ambident coordination properties, since they may bind via N, S, O, the 7t-N=S or jr-S=0 bond for example. They may be compared with allenes and naturally also with the isostructural and the isoelectronic sulfur dioxide 0=S—O.13 We will first discuss some relevant data concerning RNSNR and RNSO and subsequently the properties of the metal complexes. 

Until recently most of the mechanistic studies on nitrosation have been concerned with N-nitrosation reactions of amines, including the diazotisation reactions of primary amines. Now, work has been extended to include both O- and S-nitrosation, so that comparisons can be made. Mechanistic studies have also been extended in recent years to include reactions of nitrogen oxides, nitrosamines, alkyl nitrites, thionitrites and transition metal nitrosyl complexes. Many of these reactions have been used preparatively for a long time, but little has been known about their detailed reaction mechanisms. 

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