Synthesis, Crystal Structure, and Magnetic Properties of Hexanuclear [{MnL2}4{Nb(CN)8}2] and Nonanuclear [{MnL2}6{Nb(CN)8}3] Heterometallic Clusters (L = bpy, phen)

摘要

A hexanuclear cyano-bridged {Mn~(II)_4Nb~(IV)_2} cluster (1) bearing 2,2'-bipyridine (bpy) as the blocking ligand at manganese is obtained from the reaction of cis-[MnCl2(bpy)2] and K4[Nb(CN)8]. When the blocking ligand is 1,10-phenanthroline (phen), a nonanuclear cluster {Mn~(II)_6Nb~(IV)_3} (2) is obtained. The structure of [{Mn(bpy)2}4{Nb(CN)8}2] has been solved by single-crystal X-ray crystallography, whereas the phen derivative has been confirmed by means of the structure analysis of the corresponding W~(IV) analogue [{Mn(phen)2}6{W(CN)8}3(H2O)2]. Magnetic measurements revealed S = 9 and (27)/2 spin ground states for these aggregates as a result of antiferromagnetic Nb-Mn interaction with J_(Nb-Mn) = -18.1 cm~(-1) (1) and -13.6 cm~(-1) (2).