Group V Metal Sulphides

Vincent and C. Vincent-Forat, Bull. Soc. chim. France, 1973, 499. 

The crystal structure of tetra-arsenic pentasulphide, AS4S6, has been determined. The crystals are monoclinic, of space group P2i/w, withZ = 2 in a unit cell of dimensions a = 7.98, b = 8.10, c = 7.14 A / = 101.0 . The structure (10) is built up of discrete AS4S5 molecules of approximate symmetry with As— As = 2.55 A and mean As—S = 2.24 A. The structure of AS4S5 is quite different from those of P4S5 and P4Seg, which have an exo-cyclic sulphur and selenium atom, respectively, double-bonded to a quinque-valent phosphorus atom. 

Solid S8(AsF3)2 has been shown to react with gaseous tetrafluoroethylene at room temperature and moderate pressure to give arsenic trifluoride, 

The characteristic features of the crystal structures of antimonite, Sbg S3, have been discussed in terms of the 18-electron configuration. Thermal annealing patterns of some neutron-irradiated thio-antimony compounds suggest that the trapping of metastable species is determined, in part, by the 

Zagal skaya, and E. A. Pobedimskaya, Doklady Akad. Nauk 

Group V Metal Sulphides. As a prelude to experimental work, the existence of the anions NS3, NS2 , NO2-, COJ-, and CS4- has been considered243 in terms of semi-empirical extended Hiickel MO calculations. The calculations indicated that a number of them are capable of existence, perhaps in molten-salt or non-aqueous media, but the NS3 and NS4- ions seem unlikely to be capable of more than transient existence. 

X-Ray diffraction measurements have shown244 that the structure of the cage molecule P4S4(Me)6 is that predicted by R. R. Holmes and T. A. Forstner in 1963. The crystal structure of one of the monoclinic modifications of the compound Sn2P2S6 has been determined.245 The structure contains P2S6 groups (51) with almost undistorted point-group symmetry 

The reaction of As2S3 and As2S5 with Na2S203 has been shown248 to proceed through the decomposition of Na2S203 with the formation of 

Johnson and J. R. Wasson, Inorg. Nuclear Chem. Letters, 1974, 10, 891. 

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