Electrochemical (polarographic, cyclic voltammetric, and coulometric) and coordination behaviour of several symmetrically and unsymmetrically substituted phosphiniminocyclotrithiazenes have been studied. Polarograms of R3PN-S3N3 (R = C6H5, p-ClC6H4, p-H3CC6H4, and (OC4H8N)), Ph2(OC4H8N)PN-S3N3, and Ph(OC4H8N)2PN-S3N3 give two cathodic waves. Cyclic voltammograms of Ph3PN-S3N3 (1) and (OC4H8N)3PN-S3N3 (2) reveal nearly the same oxidation peak potential but different reduction potentials. Controlled potential electrolysis of 1 and 2 at +0.6 V indicates exocyclic cleavage and ring degradation. Cathodic reduction behaviour of Ph3PN-S3N3 suggests the possibility for the formation of 1,5-(Ph3PN)2S4N4 under electrochemical conditions. Reaction of nickel chloride hexahydrate with heterocycle 1 in 1:2 molar ratio in acetonitrile affords the complex, [Ni(S2N2H)2] (A) (90% yield) and [Ph3PNH2]Cl salt as products. Analogous reactions with other ligands of this type (two symmetrical (sym.) and three unsymmetrical (unsym.)) except 2 also give A, while ligand 2 reacts with anhyd NiCl2 in an equimolar ratio to afford a dark green, square-planar complex ((OC4H8N)3PN-S3N·NiCl2 (B)) whose ESCA results assist in providing its coordination details. The study reveals a high tendency of these heterocycles to different types of ring cleavage. Key words: phosphiniminocyclotrithiazenes, polarography and cyclic voltammetry, substituent effect, nickel complexes, ESCA.
Triphenylphosphazenium chloride has been prepared by the reaction of triphenylphosphine with trimethylsilylazide in impure, wet dichloromethane. Yields are improved as stoichiometric quantities of water are added. Colourless crystals are obtained by recrystallization from the same solvent. The crystals are triclinic, space group P1̅, Z=2, a = 894,6(3), b - 979,8(3), c = 1142,9(4) pm, α = 107,27(3), β = 93,70(3), y = 92,97(3)°. In the solid state the compound exists as [(C6H5)3PNH2]+ cations, and Cl- anions. Dimeric units are formed by H-bonding. The crystal structure contains one molecule CH2Cl2 per one molecule (C6H5)3PNH2Cl. The cation has a slightly irregular tetrahedral geometry around the P-atom with a relatively short P-N bond