title: Heterometallic Cr-Mn complexes containing cyanide and oxalate bridges.
abstract: Three heterometallic Cr-Mn compounds, {Mn(mu-ox)0.5(H2O) [Cr(phen)(CN)4]}n.n H2O.2n CH3OH, (1), {Mn(mu-ox)0.5(H2O)[Cr(bpy)(CN)4]}n.2n H2O x n CH3OH, (2), and {Mn(mu-ox)0.5(bpy)[Cr(bpy)(CN)4]}n, (3) (ox = oxalate), containing cyanide and oxalate bridges based on building blocks [Cr(L)(CN)4]- (L = phen and 2,2'-bipyridine) have been prepared. A new approach was first employed to synthesize ox-bridged compounds via facile oxidation-hydrolysis reactions of diaminomaleonitrile. X-ray crystallography revealed that the structures of 1 and 2 are similar, where cyano-bridged corrugated ladderlike chains are further connected through bis-bidentate oxalato bridges to unique two-dimensional layered structures. Of note is that the introduction of 2,2'-bipyridine led to an interesting cluster-based chainlike compound (3) with cyano-bridged squares [Mn2Cr2] extended by ox bridges. Magnetic studies show antiferromagnetic (AF) interaction between cyano-bridged Cr(III)-Mn(II) and ox-bridged Mn(II)-Mn(II) ions, with the result that 1 and 2 exhibit AF ordering with spin-flop behaviors below 18 and 19 K, respectively.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Yuan-Zhu
authors.initials: YZ
authors.lastname: Zhang
authors.forename: Zhe-Ming
authors.initials: ZM
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Gao