Zinc thiolate complexes [ZnLn(SR)]+ with azamacrocyclic ligands: Synthesis and structural properties

Article abstract of DOI:10.1002/ejic.200500947

A series of 24 novel zinc thiolate complexes containing saturated macrocyclic polyamine ligands with the general formula [Zn(L_n)(SR)] ClO₄ (L_n: n-dentate azamacrocyclic ligand) has been synthesized. Two different thiolate ligands (R = phenyl, benzyl) and 12 macrocyclic ligands with ring sizes varying from 11 to 16 atoms and containing three, four, and five nitrogen donors (including a new macrocyclic triamine ligand, 8-methyl-[11]aneN₃) have been used. The solid-state structures of 20 of the 24 complexes have been characterized by X-ray diffraction. The crystal lattice of all compounds is comprised exclusively of monomers. The tetracoordinate N₃S compounds exhibit Zn-S bond lengths ranging from 2.2259(5) to 2.2492(9) A and the pentacoordinate N ₄S systems from 2.266(2) to 2.3200(7) A. In addition, two complexes with the very rare N₅S coordination environment for zinc have been found. They exhibit Zn-S bond lengths of 2.3782(7) and 2.42 A (mean value of two independent molecules). The thiolate complexes are suitable model systems for the precursor proteins of matrix metalloproteases (pro-MMPs) as well as for thiolate alkylating enzymes such as cobalamine-dependent/ independent methionine synthases, farnesyl transferase, and the Ada repair protein. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.