The structure of Cd2(AIC14)2 has been determined by X-ray crystallography and the Cd-Cd bond length found to be 2.576 A.Morse and Jones in 1890 first reported that molten CdC12 dissolves a substantial amount of cadmium.' From their melts they obtained black solids of the composition Cd4C17, Cd4Br7, and CdI2Il3 which they claimed contained a CdJ halide as well as the CdII halide. Later, Hollens and Spencer showed that these solids were a mixture of finely divided cadmium and cadmium(rr) halide.' However, from melting point depression studies of solutions of cadmium in cadmium chloride and from the fact that the solutions are diamagnetic, Grjotheim et al. concluded that Cd22+ is formed when cadmium is dissolved in liquid cadmium chloride.3 Their magnetic measurements were in agreement with those of Farquharson and Heymann who also found these solutions to be diamagnetic.4 Grjotheirn et al. concluded that neither the Cd+ ion nor solvated cadmium atoms are present in the melts. The most recent work on CdI salts is due to Corbett and coworkers.5J~They pointed out that

The compound HgZ.86A~F6 belongs to the tetragonal space group I4,lamdwith lattice parameters n = 7.538(4) A, c = 12.339(5) A, a n d 2 = 4. Thestructure was refined using 109 symmetry independent reflections by full matrix least-squares refinement to a final R value of 0.079. T h e structure may be described as consisting of octahedral AsF6-ions arranged on a lattice which contains linear, non-intersecting channels in two mutually perpendicular directions. Within these channels are infinite chains of mercury atoms, each with a formal charge of +0.35, a n d with a mercury-mercury distance of 2.64(1) A.Le compose Hg,.,,AsF6 appartient au groupe d'espace tetragonal 14,lnmd avec les parametres de maille n = 7.538(4) A, c = 12.339(5) A, and Z = 4. En utilisant 109 reflexions symetrie independante la structure a CtC raffinee par une methode de matrice complbte des moindres carrCs B une valeur finale du facteur R &gal a 0.079. On peut decrire la structure comme si elle consiste des ions octaedrique AsF6-qui se trouvent sur un reseau qui contient les canaux IinCaire en deux directions mutuellement perpendiculaire et qui ne se coupent pas. Dans ces canaux se trouvent les chaines infinies d'atomes de mercure, dont chaque atome porte line charge formelle de +0.35, et qui ont une distance mercure-mercure de 2.64(1) A.

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. Can. J. Chem. 53,3147 (1975). The compound S3N2+AsF6-has been prepared by the reaction of S4N4 with AsF,. The crystal structure has been determined from three-dimensional X-ray counter data. Crystals are monoclinic, space group P2,lc with a = 8.499(4), b = 8.298(4), c = 11.069(8), j 3 = 94.59(5), V = 778.1 A3, Z = 4, and D, = 2.67 g ~m -~. The structure was solved by Patterson methods and reiined to a conventional R factor of 0.028 for 798 independent reflections with I > 3o(I).The structure consists of discrete AsF6-ions and planar cyclic S3N2+ ions. Solutions of S3N2+AsF6-in methylene chloride gave a five-line electron spin resonance spectrum with an intensity ratio of 1 : 2 : 3 : 2 :1 showing that the unpaired electron in S3N2+ is coupled to two equivalent nitrogen atoms in full accord with the results of the crystal structure determination. planaires cycliques S3Nz+ et en anions AsF6-discrets. Des solutions dans du chlorure de mkthyl6ne ont donnk un spectre de rksonance paramagnktique klectronique montrant cinq bandes avec un rapport d'intensitks de 1 : 2 : 3 : 2: 1 ce qui indique que l'klectron apparik de S3N2+ est couplk avec deux atomes d'azote qui sont kquivalents comme le montrent les rksultats de la dktermination de la structure cristalline.[Traduit par le journal]