POLYSULFONYL AMINES .37. PREPARATION OF MERCURY DIMESYLAMIDES - CRYSTAL AND MOLECULAR-STRUCTURES OF HG[N(SO2CH3)2]2, HG[(N(SO2CH3)2)2(DMSO)2], AND HG[(N(SO2CH3)2)2(HMPA)]

Hg[N(SO2CH3)2]2 (1) and Hg2[N(SO2CH3)2]2 (2a) are formed as colourless, sparingly soluble precipitates when solutions of Hg(NO3)2 or Hg2(NO3)2 in dilute nitric acid are added to an aqueous HN(SO2CN3)2 solution. By a similar reaction, Hg2[N(SO2C6H4-Cl-4)2]2 is obtained. 1 forms isolable complexes of composition Hg[N(SO2CH3)2]2 . 2 L with L = dimethyl sulfoxide (complex 3a), acetonitrile, dimethyl formamide, pyridine or 1, 10-phenanthroline and a (1/1) complex Hg[N(SO2CH3)2]2 . HMPA (4) with hexamethyl phosphoramide. Attempted complexation of 2 a with some of these ligands induced formation of Hg0 and the corresponding Hg(II) complexes. Crystallographic data (at -95-degrees-C) are for 1: space group I4(1)/a, a = 990.7(2), c = 2897.7(8) pm, V = 2.844 nm3, Z = 8, D(x) = 2.545 Mg m-3; for 3a: space group P1BAR, a = 767.8(2), b = 859.2(2), c = 925.2(2) pm, alpha = 68.44(2), beta = 86.68(2), gamma = 76.24(2)-degrees, V = 0.5510 nm3, Z = 1, D(x) = 2.113 Mg m-3; for 4: space group P2(1)/c, a = 1041.3(3), b = 1545.4(3), c = 1562.5(3) pm, beta = 100.30(2)-degrees, V = 2.474 nm3, Z = 4, D(x) = 1.944 Mg m-3. The three compounds form molecular crystals. The molecular structures contain a linear or approximately linear, covalent NHgN moiety; the Hg-N distances and N-Hg-N angles are 206.7(4) pm and 176.3(2)-degrees for 1, 207.2(2) pm and 180.0-degrees for 3a, 205.7(4)/206.7(4)pm and 170.5(1)-degrees for 4. In the complexes 3a and 4, the O-ligands are bonded to the Hg atoms perpendicularly to the N-Hg-N axes, leading in 3a to a square-planar trans-(N2O2) coordination with Hg-O 261.2(2) pm and N-Hg-O 92.3(1)/87.7(1)-degrees, in 4 to a slightly distorted T-shaped (N2O) geometry with Hg-O 246.2(4) pm and N-Hg-O 96.7(1)/92.0(1)-degrees. In all three structures, the primary coordination is extended to a severely distorted (N2O4) hexacoordination by the appropriate number of secondary, inter- and/or intramolecular Hg...O interactions (O atoms from sulfonyl groups, Hg...O distances in the range 280 - 300 pm). The intramolecular Hg...O interactions give rise to nearly planar four-membered [HgNSO] rings. The molecule of 1 has a two-fold axis through the bisector of the N-Hg-N angle, the molecule of 3a an inversion center at the Hg atom. The molecule of 4 has no symmetry.