Synthesis, X-ray single crystal and magnetic study of new heteroleptic late transition metal alkoxides with tetranuclear square planar metal core, Co4Cl2(OC2H4OEt)6, Co4(OMe)2(acac)6(MeOH)2 and Zn4(OMe)2(acac)6(C7H8)

Interaction of 4 equiv. CoCl2 with 6 equiv. of NaOC2H4OEt in toluene/HOC2H4OEt medium provided Co4Cl2(OC2H4OEt)(6) (1) with practically quantitative yield. Reaction of Co(acac)(2) with Ti(OMe)(4) in 1:1 ratio in toluene gave Co-4(OMe)(2)(acac)(6)(MeOH)(2) (2) with moderate yields. The same reaction for Zn(acac)(2) resulted in formation of Zn-4(OMe)(2)(acac)(6)(C7H8) (3), The structures of 1-3 contain planar tetranuclear cores of M-4(mu(3)-OR)(2)(mu(2)-OR)(4) type ([Ti(OMe)(4)](4) type structure), where the metal atoms are pentacoordinated in 1, hexacoordinated in 2, and both penta- and hexacoordinated in 3. The magnetic measurements have revealed competing ferromagnetic and antiferromagnetic interactions between the 4 Co(II) atoms in 1, but only ferromagnetic in 2. (C) 2003 Elsevier Ltd. All rights reserved.