Interactions of a Cationic Mercury(II) Thiolate Complex [Hg(Tab)2](PF6)2 with N-Donor Ligands

Abstract

Reactions of [Hg(Tab)(2)](PF(6))(2) (1) with phen, 2,2'-bipy, py, N-Meim, N-(i)Prim, en, eten, tmen, dap, and dpt gave rise to a family of cationic mercury(II) thiolate complexes, [Hg(Tab)(2)(L)](PF(6))(2).S (2, L = phen, S = 2MeOH; 3, L = 2,2'-bipy, S = DMF), [Hg(Tab)(2)(L)(2)](PF(6))(2) (4, L = py; 5, L = N-Meim), [Hg(Tab)(2)(N-(i)Prim)](PF(6))(2) (6), [Hg(Tab)(2)(L)](PF(6))(2).0.5MeCN (7, L = en; 8, L = eten), and [Hg(Tab)(2)(L)](PF(6))(2) (9, L = tmen; 10, L = dap; 11, L = dpt). These complexes were characterized by elemental analysis, IR spectra, UV-vis spectra, (1)H NMR, and single-crystal X-ray crystallography. The Hg atom in [Hg(Tab)(2)](2+) dications of 2-5 is further coordinated either by two N atoms from one phen or 2,2'-bipy ligand or by two N atoms from two py or N-Meim ligands, affording a distorted seesaw-shaped coordination geometry. In 6, the Hg atom of the [Hg(Tab)(2)](2+) dication is coordinated by one N atom of the N-(i)Prim ligand, forming a T-shaped coordination geometry, and these [Hg(Tab)(2)(N-(i)Prim)](2+) dications are further coordinated to another S atom of Tab from the adjacent unit, giving a chain structure. The Hg atoms in [Hg(Tab)(2)](2+) dications of 7-11 are chelated by two N atoms from one diamine molecule such as en in 7, eten in 8, tmen in 9, or dap in 10 or by two N atoms from the triamine molecule dpt in 11, forming a distorted seesaw-shaped coordination geometry. In all of these structures, the original trans configuration of the [Hg(Tab)(2)](2+) dication of 1 is changed via rotation and/or switching of the two Tab species along the S-Hg-S line together with the rotation of the phenyl groups of the Tab ligands. The results may provide interesting insight into mimicking of the interactions of the Hg(Cys)(2) linear species in Hg-MerR and Hg-MT with various N-donor ligands encountered in nature and its potential changes in the structural chemistry (bond length, angles, configurations, etc.).