Proteins containing copper in their active sites represent a large and significant class of metallobiomolecules.1 The Type 1 Blue Copper Proteins (BCP) are fundamentally important for their ability to transfer electrons and exhibit unusual spectroscopic and geometric properties.2 The ligand 1,8-dithia-4,11-diazacyclotetradecane (14[ane]N2S2) is a synthetic target analogous to the active site of BCP. Analysis of ligand L1 using X-ray Crystallography, Cyclic Voltammetry (CV), Electron Paramagnetic Resonance (EPR) and Ultra-Violet/Visible Spectroscopy (UV/Vis) are presented. X-ray analysis confirmed square planar geometry in CuII and distorted tetrahedron in CuI. UV-Vis showed three absorption bands at 295, 350 and 550 nm with a binding constant of 9.34 X 102 M-1 at pH 5. The ligand is quasi-reversible with a redox potential of +119 mV vs Ag/AgCl, which indicates the stabilization of the CuI species. EPR is consistent with the square planar geometry observed in the X-ray structure. Due to the alternating N-S heteroatoms in L1, reaction with dibromoethane to afford L2 will provide insight into the reversibility and stability of CuII/I complex when the flexibility is restricted.3 This presentation will focus on the synthesis of the ligands along with a detailed explanation of the results. References 1. Tolman, W. B.; Yang, L. J. Biol. Inorg. Chem. 17, 285-291 (2012) 2. Marks, T.J. In Synthetic Analogues of the Active Site in Blue Copper Proteins Vol 2; Plenum Press: New York, NY, 1978, pp 285-300. 3. a) Wadas, T. J.; Wong, E. H.; Weisman, G. R.; Anderson, C. J. Chem. Rev. 2010, 110, 2858-2902. (b) Ferdani, R.; Stigers, D. J.; Fiamengo, A. L.; Wei, L.; Li, B. T.; Golen, J. A.; Rheingold, A. L.; Weisman, G. R.; Wong, E. H.; Anderson, C. J. Dalton Trans., 2012, 41, 1938.

Blue copper protein models: Characterization of copper (I/II) complexes of the N2S2 macrocycle 1,8-dithia-4,11-diazacyclotetradecane and derivatives

249th National Meeting (2015)

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