Tetracyanide-bridged divanadium complexes: redox switching between strong antiferromagnetic and strong ferromagnetic coupling

Matthew P Shores; Jeffrey R Long

doi:10.1021/ja025512n

Tetracyanide-bridged divanadium complexes: redox switching between strong antiferromagnetic and strong ferromagnetic coupling

J Am Chem Soc. 2002 Apr 10;124(14):3512-3. doi: 10.1021/ja025512n.

Authors

Matthew P Shores¹, Jeffrey R Long

Affiliation

¹ Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.

PMID: 11929233
DOI: 10.1021/ja025512n

Abstract

Reaction of [(Me3tacn)V(CF3SO3)3] (Me3tacn = N,N',N''-trimethyl-1,4,7-triazacyclononane) with LiCN in DMF results in oligomerization of cyanide to form [(Me3tacn)2V2(CN)4(mu-C4N4)]. The structure of this binuclear complex features a planar tetracyanide unit bridging two VIV centers via imido type linkages. The conjugated pathway provided by the bridging ligand leads to strong antiferromagnetic coupling (J = -112 cm-1) and an S = 0 ground state. Reduction of the complex with cobaltocene generates the Class III mixed-valence anion [(Me3tacn)2V2(CN)4(mu-C4N4)]1-, wherein resonance exchange induces strong ferromagnetic coupling to give a well-isolated S = 3/2 ground state.