Crystal structures of three mercury(II) complexes [HgCl(2) L] where L is a bidentate chiral imine ligand

The crystal structures of three complexes [HgCl(2) L] were determined, namely, (S)-(+)-di­chlorido­[1-phenyl-N-(pyridin-2-yl­methyl­idene)ethyl­amine-κ(2) N,N′]mercury(II), [HgCl(2)(C(14)H(14)N(2))], (S)-(+)-di­chlorido­[1-(4-methyl­phen­yl)-N-(pyridin-2-yl­methyl­idene)ethyl­amine-κ(2) N,N′]mercury(II), [HgCl(2)(C(15)H(16)N(2))], and (1S,2S,3S,5R)-(+)-di­chlorido­[N-(pyridin-2-yl­methyl­idene)isopino­camph­eyl­amine-κ(2) N,N′]mercury(II), [HgCl(2)(C(16)H(22)N(2))]. The complexes consist of a bidentate chiral imine ligand coordinating to HgCl(2) and crystallize with four independent mol­ecules in the first complex and two independent mol­ecules in the other two. The coordination geometry of mercury is tetra­hedral, with strong distortion towards a disphenoidal geometry, as a consequence of the imine bite angle being close to 70°. The Cl—Hg—Cl angles span a large range, 116.0 (2)–138.3 (3)°, which is related to the aggregation state in the crystals. For small Cl—Hg—Cl angles, complexes have a tendency to form dimers, via inter­molecular Hg⋯Cl contacts. These contacts become less significant in the third complex, which features the largest intra­molecular Cl—Hg—Cl angles.