NEW ORGANOMERCURY(II) DERIVATIVES CONTAING ORGANOPHOSPHORUS LIGANDS. CRYSTAL AND MOLECULAR STRUCTURES OF HgX[(SPPh2)2N] 
(X = Cl, Br, I)

Oana Bumbu and Cristian Silvestru

“Babes-Bolyai” University, Faculty of Chemistry & Chemical 
Engineering, 11 Arany Janos St., RO-400028 Cluj-Napoca, Romania;
E-mail:  oanab@chem.ubbcluj.ro 

Organomercury(II) halides of the type HgX[(SPPh2)2N], [X = Cl (1), Br (2), I (3)] were been prepared by reacting HgX2 and K[(SPPh2)2N], in dichloromethane, in 1:1 molar ratio. All compounds were investigated by solution NMR (1H, 13C, 31P) spectroscopy, mass spectrometry and single-crystal X-ray diffraction. The 31P NMR spectra of complexes 1 – 3, recorded at room temperature, show only one resonance, with chemical shifts indicative of deprotonated phosphorus ligands and coordination through both chalcogen atoms of a ligand moiety to the metal center. According to 1H and 13C NMR spectra the organic groups attached to the phosphorus atom are equivalent, thus indicating a rapid exchange process of the conformation of the six-membered HgS2P2N rings in solution, at room temperature. In complexes 1, 2 and 3 the coordination geometry around the metal centre is distorted tetrahedral. The HgS2P2N chelate rings are arranged in a distorted chair conformation, with Hg and N atoms in the apices. The molecules of HgCl[(SPPh2)2N] are associated in the crystal into dimers through asymmetric Cl-Hg∙∙∙Cl bridges (Hg-Cl 2.578, Hg∙∙∙Cl 2.616 Å), leading to a planar four-membered Hg2Cl2 ring. The reactions of HgCl[(SPPh2)2N] with alkali metal salts of potential bidentate ligands (e.g. dithiocarbamates) and [2-(Me2NCH2)C6H4]Li were investigated by means of multinuclear (1H, 13C, 31P) NMR spectroscopy in solution.

HgCl[(SPPh2)2N]