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A series of complexes of ruthenium(II) with the strong -acceptor ligand 2-(phenylazo)pyridine (Azpy), [Ru(Azpy)2(AB)]"+, have been prepared. The coligands (AB) include Azpy, 2,2'-bipyridyl, 4,4'-bithiazole, 1,2-diaminoethane, 2,4-pentanedione anion, and X2 (X = N02", CN", Br", N3", and thiourea). Infrared spectra show the Azpy azo stretching mode to be diagnostic of the coligand (AB) -accepting behavior, with strongly -accepting coligands giving the highest Azpy y(N=N). Visible spectra of the complexes consist of intense charge-transfer bands; the first CT band is not found to be a valid criterion for Ru-ligand bonding. It is proposed that both and effects are important, causing the observed nonlinear behavior. Emission spectra could be obtained for three of the compounds, one compound appearing to give multiple emissions. Cyclic voltammetry data support the strong stabilization. Oxidation to Ru(III) could be observed in only a few complexes.However, all reduce at relatively high potentials, with RuAzpy32+ reducing near 0 V (vs.SCE). A new thin-layer chromatography technique for cationic ruthenium complexes has been developed.

recently reported for it by others,5 who obtained it by the reaction of Cs+(SF5)2N" with F2.The mechanism for the formation of 21 is clearly complex and may well be due to the formation of an intermediate anion, SF5NFSF4NP, in analogy to the formation of CF3NFCF2NFf rom F2C=NF and F-: r F4S=nf F4S=NF -1- + other productsIn contrast to its chlorinated analogue, F4S=NC1,23 which spontaneously dimerizes to a cyclic four-membered ring compound, (F4SNCl)2,llq F4S=NF shows no tendency to form such a dimer, even when heated. In another attempt to induce (23) SF4=NC1 has never been isolated, but it is assumed to be the precursor to the cyclic dimer.1,q dimerization, photolysis of F4S=NF was tried. After 1 h of ultraviolet irradiation through Pyrex glass, F4S=NF was recovered unchanged. Irradiation through quartz resulted in partial decomposition of F4S=NF, with production of products similar to those found after its decomposition in the presence of KF. These included SF4, SF6, N2, and, interestingly, (SF5)2NF (21). In this case, the formation of 21 may proceed by a mechanism similar in many respects to that proposed by others5a,c-d'f for the formation of F4S=NSF5 from F2 and nsf3.

The complexes [Ru(bpy)

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