Crystal Structure of Tris(1,10-phenanthroline)mercury(II) Trifluoromethanesulfonate

Abstract

The crystal structure of the ethanol solvate of the title compound, [Hg(phen)₃](CF₃S0₃)₂ (phen =1,10-phenanthroline), has been determined at 295(1) K by single-crystal X-ray diffraction and refined by least squares to a residual of 0·043 for 2939 'observed' reflections. Crystals are monoclinic: C2/c, a 25·25(1), b 10·960(4), c 18·949(6) Å, β 129·32(2)º, Z 4. The cation is centred on a crystallographictwofold axis and has approximate D₃ point symmetry. The deviation of the mercury(II) environment from octahedral symmetry toward the trigonal-prismatic limit is considerable, the mean trans N-Hg-N angle being 154·52º. <Hg-N> is 2·40₀ Å. The unit cell volume is considerablydependent on crystallization solvent, being larger for the ethanol solvate than for solvent-free crystals obtained from aqueous solution.