Preparation and structural characterization of mercury 21-thiaporphyrin complex:: HgII(Stpp)Cl (Stpp = tetraphenyl-21-thiaporphyrin anion)

Treatment of tetraphenyl-21-thiaporphyrin (StppH) with Hg(OAc)(2) in CH2Cl2 yields diamagnetic H-II(Stpp)Cl complex. The coordination sphere around Hg2+ in the monomeric molecule is described as a five-coordinate distorted trigonal bipyramid with the bonding to the three pyrrole nitrogens [Hg(1)-N = 2.104(4), 2.626(4), 2.640(4) Angstrom], the thiophene sulfur [Hg(1)-S = 2.801(1) Angstrom], and one axial chloride ligand [Hg-(1)-Cl(1) = 2.318(1) Angstrom]. The plane of the three pyrrole nitrogen atoms [i.e., N(1), N(2), N(3)] bonded to Hg2+ is adopted as a reference plane 3N. Because of its larger size, the Hg2+ is considerably out of the 3N plane; its displacement of 1.41 Angstrom is in the same direction as that of the apical Cl- ligand. The thiophene ring is slightly folded so that the dihedral angle between the C(13)-C(14)-C(15)-C(16) and C(13) S(1) C(16) planes is 7.3degrees. (C) 2002 Elsevier Science B.V. All rights reserved.