Transition metal salts of 2-amino-3,5-dihalopyridine - dimers: syntheses, structures and magnetic properties of (3,5-diCAPH)2Cu2Br6 and (3,5-diBAPH)2Cu2X6

Jason Anagnostis, Clark University
Joris Cipi, Clark University
Christopher P. Landee, Clark University
Grant W. Tremelling, Clark University
Mark M. Turnbull, Clark University
Brendan Twamley, Trinity College Dublin
Jan L. Wikaira, University of Canterbury

Abstract

Three dimeric copper(II) complexes have been prepared with the general formula bis(2-amino-3,5-dihalopyridinium)hexahalodicuprate cuprate(II): (3,5-diCAPH)2Cu2Br6 (1), (3,5-diBAPH)2Cu2Cl6 (2) and (3,5-diBAPH)2Cu2Br6 (3) [3,5-diCAPH = 2-amino-3,5-dichloropyridinium; 3,5-diBAPH = 2-amino-3,5-dibromopyridinium]. The compounds have been characterized via single crystal X-ray diffraction and temperature dependent magnetic susceptibility measurements. All three compounds crystallize in monoclinic space groups (1, C2/c; 2 and 3, P21/c) and exhibit alternating layers of hexahalodicuprate ions and organic cations. The hexahalodicuprate ions exhibit short X⋯Cu and X⋯X contacts which link the dimers into a square array. Variable temperature magnetic susceptibility data reveal strong intradimer antiferromagnetic exchange (J = −153, −65, −122 K for 1–3, respectively), but negligible inter-dimer magnetic exchange.