title: 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).
abstract: A hexanuclear cyano-bridged {MnII4NbIV2} 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 {MnII6NbIV3} (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 WIV 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 JNb-Mn=-18.1 cm(-1) (1) and -13.6 cm(-1) (2).
authors.affiliation: Laboratoire de Chimie de Coordination du CNRS, Université Paul Sabatier, 205 route de Narbonne, 31077 Toulouse, France.
authors.forename: Thengarai S
authors.initials: TS
authors.lastname: Venkatakrishnan
authors.forename: Raghunathan
authors.initials: R
authors.lastname: Rajamani
authors.forename: S
authors.initials: S
authors.lastname: Ramasesha
authors.forename: Jean-Pascal
authors.initials: JP
authors.lastname: Sutter