Affiliation: | aDepartment of Chemistry, WestCHEM, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, United Kingdom bAmes Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA cDepartment of Chemistry, Yale University, New Haven, CT 06520, USA dDepartment of Chemistry, Iowa State University, Ames, IA 50011, USA |
Abstract: | The coordination chemistry of the tetradentate pyridyl N-donor ligand cis-3,5-bis-[2-pyridinyleneamin]-trans-hydroxycyclohexane (DDOP) has been investigated with zinc(II) nitrate and triflate. The resulting complexes, [Zn(DDOP)(H2O)(NO3)](NO3) (1), and [Zn(DDOP)(H2O)(OTf)](OTf) (2) differ not only in their counterions, but also the arrangement of the axial ligands and their solid state hydrogen bonded networks. Isothermal titration calorimetry was used to assess the difference in binding properties exhibited by the two zinc complexes at physiological pH in an aqueous environment. A series of coordinating amino acids were found to preferentially bind to the mononuclear zinc triflate (1) complex over the corresponding nitrate (2) assembly, with histidine exhibiting a two centre binding mode. |