Crystal and Molecular Structure of the 2:1 Adduct of Bis(pentafluorophenyl)mercury(II) and Bis(diphenylarsino)methane

The title compound crystallizes in the monoclinic system with a = 14.07, b = 17.34, c = 19-33 8, beta = 91" 3'. Z = 4, and space-group C2/c. The structure was solved by conventional Patterson and Fourier methods and refined by least-squares techniques to R 0.9 for 1218 independent reflections. The compound has a two-fold axis about the methylene carbon atom of the diarsine moiety. Each mercury atom has one arsenic atom within the sum of van der Waals radii from it, and there is a T-shaped distribution of two C6F5 groups and the arsenic atom about mercury with a Hg...As distance of 3.40 +/- 0.02 A and C-Hg-C angle of 173 +/- 4'. X-Ray powder diffraction photographs indicate that the compound [(C6F5)2Hg],Ph2PCH2PPh2 has the same structure