Defective Double-Cubane, Tetranuclear Manganese(II) and Cobalt(II) Complexes with Simultaneous μ1,1-Azido and μ-O Bridges

The reactions of M(O2CCH3)2·4H2O (M= Mn, Co) with di-2-pyridyl ketone, (py)2CO, and NaN3 in CH3OH or CH3OH/H2O allow isolation of the tetranuclear compounds [Mn4(μ1,1-N3)2(N3)2{(py)2C(OH)O}2{(py)2C(OCH3)O}2] (1) and [Co4(μ1,1-N3)2(N3)2{(py)2C(OH)O}2{(py)2C(OCH3)O}2]·2H2O (2). X-ray diffraction analysis reveals defective double-cubane tetrameric entities in which the MnII or CoII atoms are linked by μ1,1-N3 bridges and two kinds of O-bridges. The molar magnetic susceptibility measurements of 1 and 2 in the 2−300 K range indicate weak antiferromagnetic coupling for 1 and clear bulk ferromagnetic coupling for 2.