| Abstract: | Cu(H2O)(PzTz)2](NO3)2 (1), Cu(μ-NO3)(NO3)(DMPzTz)] n (2), and {Cu(NO3)(DPhPzTz)}2(μ-NO3)2] (3) PzTz?=?2-(1-pyrazolyl)-1,3-thiazine, DMPzTz?=?2-(3,5-dimethyl-1-pyrazolyl)-1,3-thiazine, DPhPzTz?=?2-(3,5-diphenyl-1-pyrazolyl)-1,3-thiazine] have been prepared and characterized by elemental analysis, electronic spectroscopy, IR spectroscopy, electron paramagnetic resonance spectroscopy, magnetic susceptibility measurements, and single-crystal X-ray diffraction. Influence of ligand size on coordination to Cu(II) has been analyzed. The three complexes are five-coordinate and the coordination geometry can be described as a distorted trigonal bipyramid for 1 or a distorted square pyramid for 2 and 3. As a consequence of the strain induced by the ligands, 1 is a monomeric complex cation whereas 2 is a polymer and 3 is a dimer. |
