Polynuclear intermediates in the synthesis of cyclometallated complexes; the crystal and molecular structure of (2-pyridylphenyl)mercury(II) chloride tetramer

Abstract
The complex [HgLCl](HL = 2-phenylpyridine) is a useful intermediate in the preparation of cyclometallated transition metal complexes and the molecular structure of the complex reveals an unexpected tetrameric arrangement reminiscent of the ‘ladder’ structure observed in organolithium derivatives; contrary to expectations the Hg–N contact is very long (> 2.6 Å) but an unusual semi-bridging Hg–C–Hg interaction is observed.