New organomercury(II) compounds containing intramolecular N → Hg interactions: crystal and molecular structure of [2-(Me2NCH2)C6H4]HgCl and [2-(Me2NCH2)C6H4]Hg[S(S)PPh2]

[2-(Me2NCH2)C6H4]HgCl (1) was prepared by reacting HgCl2 with [2-(Me2NCH2)C6H4]Li in diethyl ether. The reactions of 1 with the sodium or ammonium salt of the appropriate thiophosphinato ligand, in 1:1 molar ratio, afford the isolation of [2-(Me2NCH2)C6H4]Hg[S(S)PR2] [R=Me (2), Et (3), Ph (4)], [2-(Me2NCH2)C6H4]Hg[S(O)PPh2] (5) and [2-(Me2NCH2)C6H4]Hg[S(S)P(OiPr)2] (6). The compounds were investigated by IR and multinuclear NMR (1H, 13C and 31P) spectroscopy. The molecular structures of 1 and 4 were determined by single-crystal X-ray diffraction. Due to the strong intramolecular coordination of the N atom of the pendant CH2NMe2 arm [Hg(1)–N(1) 2.764(6) and 2.725(4) Å in 1 and 4, respectively] both compounds exhibit a T-shaped (C,N)HgX core in the molecular unit, with almost linear arrangement of the covalent bonds [C(1)–Hg(1)–Cl(1) 176.93(18)° in 1, and C(1)–Hg(1)–S(1) 169.54(16)° in 4]. The crystals of 1 contain discrete monomeric molecules, while the crystals of 4 contain dimer associations built through asymmetric bridging dithiophosphinato ligands [Hg(1)–S(1) 2.3911(16) Å, Hg(1)⋯S(2a) 3.102(2) Å], thus resulting in an overall pseudo-trigonal bipyramidal (or seesaw) (C,N)HgS2 core, with the nitrogen atom and the weekly bonded sulfur atom in equatorial positions [N(1)–Hg(1)⋯S(2a) 82.01(10)°].