Bildung eines koordinations-stabilisierten PIIIN3S2-Sechsrings bei der Umsetzung von Pentacarbonylmetall-Komplexen der Organophosphorchloride RPCl2 (R = tBu, Ph, Cl) mit Dikaliumschwefeldiimid, K2SN2. Röntgenstrukturanalyse von (CO)5Cr[P(tBu)NSNSNH]☆

The reaction of the chlorophosphane complexes (CO)5Cr[RPCl2] (R = tBu, Ph) and (CO)5M[PCl3] (M = Cr, W) with the salt K2SN2 (11) in acetonitrile leads to the formation of six-membered PIIIN3S2 rings which are stabilized by coordination to the pentacarbonylmetal fragment. The products (CO)5Cr[P(R)NSNSNH] (R = tBu (1a), Ph (1b)) and (CO)5M[P(NH2)NSNSNH] (M = Cr (4), W (5)) were identified from their mass and IR as well as their 1H, 13C and 31P NMR spectra. In the case of the reaction of (CO)5Cr[tBuPCl2], two products of hydrolysis, (CO)5Cr[tBuP(NH2)2] (2) and SNP(tBu)(NH2)[Cr(CO)5]2 (3) which are formed during chromatographic work-up on silica, were isolated in addition to (CO)5Cr[P(tBu)NSNSNH] (1a). The X-ray diffraction study of 1a revealed an octahedral chromium complex in which the [Cr(CO)5] fragment occupies the axial position at the phosphorus of the six-membered ring ligand. The ring adopts a half-boat conformation, with the N(H) nitrogen out of the plane of the five other ring atoms; it contains a localized sulfur diimide (S=N 1.523(5) and 1.550(7) A, angle NSN 120.1(4)°) and a diaminosulfane (SN 1.690(8) and 1.684(6) A, angle NSN 108.1(4)°) sub-unit. The geometries of the related dithiatriazene six-membered rings are compared with that of 1a.