Pyridine type complexes of transition-metal halides XI. Structural, thermal and spectroscopic studies of aminopyridine complexes of cobalt(II) halides

Crystalline ternary mixed aminopyridine complexes of cobalt(II) chlorides a nd cobalt(II) bromides have been prepared and analysed by means of thermal (TG, DTG, DTA) methods, UV/VIS spectroscopy, magnetic measurements and X-ra y powder diffraction techniques. The symmetry and cell dimensions have been calculated using TREOR 90, a trial-and-error indexing program. One of the compounds, namely the [Co(3-NH2-pyridine)(4)Cl-2] complex has been studied also by X-ray single-crystal diffraction, yielding a propeller-shaped molec ule with octahedral co-ordination, exhibiting both molecular and crystallog raphic inversion symmetry. Crystal data: C20H24N8Cl2Co, M-W = 506.30, tricl inic (P (1) over bar) unit cell with a = 7.684(1), b = 8.582(1), c = 9.966( 2) Angstrom, alpha = 73.17(1), beta = 69.97(1), gamma = 70.33(1)degrees, V- c = 570.0(2) Angstrom(3) and Z = 1. The structure model was refined to R = 0.027 and wR = 0.037 for 2680 reflections with I > 3 sigma(I).