THE CRYSTAL STRUCTURE OF A COPPER(II) ISOTHIOCYANATE

BENJAMIN MARC RIDGWAY; FABIO DOCTOROVICH; , FLORENCIA DI SALVO

Mar del Plata

Congreso; X Reunión Anual de la AACr; 2014

AACr

The crystal structure of a cationic five coordinate copper(II) complex is presented. During preparation of molecular-square mixed-metal complexes [1] both crystals of the red target material and an unreported green crystalline compound was also identified: this, the title compound, was subsequently prepared directly from copper(0), bipyridine and ammonium thiocyanate. This green complex was found to have crystallised in P-1 and consist of copper(II) cations, bipyridine and thiocyanate anions. The structure of the cation is a distorted square based pyramid with a bipyridine nitrogen in the apical position and the features characteristic p-p stacking interactions as seen in other compounds of this class, for example [Cu(bipy)(NCS)2] and [Cu(bipy)2(I)][I] [2,3]. The ligated thiocyanate is almost linear (Cu-N-C) consistent with searches of the CSD [4,5]. Initial DFT [6] pre-optimization calculations (BP86/6-31G*/SDD) of the structure show a increased bend in the thiocyanate ligand suggesting that crystal packing effects may enforce linearity. A thiocyanate counter anion is present but has no significant interactions. Thiocyanate ligands can bind through sulfur or nitrogen correlating with the hardness of the metal. Previously thiocyanate coordinated transition metal complexes with ammine ligands have been shown to undergo single crystal linkage isomerisation to a metastable state under exposure to UV-visible light [7]. This ligand photo-induced linkage isomerism is of particular interest as there is potential use in data storage devices. Other ligands that frequently show ligand isomerisation contain nitrosyl, sulfur dioxide and nitrogen dioxide [8]. Photoisomerization experiments on the reported complex are under investigation Refererences [1]Vreshch, Olesia V., Oksana V. Nesterova, Vladimir N. Kokozay, Brian W. Skelton, Carlos J. Gómez García, and Julia Jezierska. Inorg Chem Comm 12, 9 (2009): 890-894. [2] Parker, O. J., B. L. Wilson, and G. L. Breneman. Acta Cryst., C50, 11 (1994): 1681-1683. [3] Barclay, G. A., B. F. Hoskins, and C. H. L. Kennard. J. Chem. Soc. (1963): 5691-5699. [4] F. H. Allen, Acta Cryst., B58, 380-388, (2002). [5] CSD version 5.35 [6] Coppens, Philip, Irina Novozhilova, and Andrey Kovalevsky. Chemical reviews 102, 4 (2002): 861-884. [7] Neese, F. Comput Mol Sci Wires, 2: (2012): 73?78. [8] Burmeister, John L., and Fred Basolo. Inorganic Chemistry 3, 11 (1964): 1587-1593.