Metal Substitution and Solvomorphism in Alkylthiolate-Bridged Zn₃ and HgZn₂ Metal Clusters

The impact of substituting Hg­(II) for Zn­(II) in a thiolate-bridged trinuclear cluster with parallels to a metallothionein metal cluster was investigated. A new solvomorph of [Zn­(ZnL)2]­(ClO4)2 (1) (L = N-(2-pyridylmethyl)-N-(2-(ethylthiolato)-amine) and five solvomorphs of a new compound [Hg­(ZnL)2]­(ClO4)2 (2) were characterized by single-crystal X-ray crystallography. The interplay of hydrogen bonding and aromatic-packing interactions in producing lamellar, 2D lamellar, and columnar arrangements of complex cations in the crystalline state is discussed. Both variable temperature proton nuclear magnetic resonance and electrospray ion-mass spectrometry (ESI-MS) suggest that the complex ions of 1 and 2 are the predominant solution species at moderate concentrations. ESI-MS was also used to monitor differences in metal ion redistribution as 1 was titrated with Hg­(ClO4)2 and [HgL(ClO4)]. These studies document the facile replacement of Zn­(II) by Hg­(II) with the preservation of the overall structure in thiolate-rich clusters.