Crystal structures of copper(II) complexes of 2-formylpyridine substitutedthiosemicarbazones; the first example of a coordinated thiosemicarbazone with a thiol function

The crystal structures of two 5-coordinate copper(II) complexes containing neutral, tridentate 2-formylpyridine N(4)-substituted thiosemicarbazones ha ve been determined. 2-Formylpyridine N(4)-cyclohexylthiosemicarbazone, HFo4 CHex coordinates via the pyridine nitrogen, imine nitrogen and thione sulfu r with two chloro ligands to produce [Cu(BFo4CHex)Cl-2]. Similarly, 2-formy lpyridine 3-(4-methylpiperazine)thiosemicarbazone, HFoppz4M, produces [Cu(H Foppz4M)Cl-2] with one major difference; rather than the expected thione fo rm of the thiosemicarbazone moiety, it coordinates as the thiol isomer. Bot h complexes are close to a square pyramid structure with axial and equatori al chloro ligands and the thiosemicarbazone moieties of both ligands nearly planar. Also included is the crystal structure of N-cyclohexylthiosemicarb azide, CHextsc. (C) 2001 Elsevier Science B.V. All rights reserved.