Syntheses, Structures, and Electrochemical Properties of Metallacyclic Oxidovanadium(V) Complexes with Asymmetric Multidentate Linking Ligands.

Trinuclear metallacyclic oxidovanadium(V) complexes, [{VO(L 3+2 R)} 3 ] ( 1 - 3 ) with asymmetric multidentate linking ligands (H 3 L 3+2 R: R = H, Me, Br), were synthesized. The molecular structure of 1 is characterized as a tripod structure, with each V(V) ion coordinated by ONO -atoms from a tridentate Schiff base site and ON -atoms from a bidentate benzoxazole site of two respective H 3 L 3+2 H ligands. The intramolecular V⋯V distances range from 8.0683 to 8.1791 Å. Complex 4 is a mononuclear dioxidovanadium(V) complex, (Et 3 NH)[VO 2 (HL 3+2 H)]. Cyclic voltammograms of 1 - 3 in DMF revealed redox couples attributed to three single-electron transfer processes.