Synthesis, structure characterization and properties of a new oxidovanadium(IV) coordination polymer incorporating bridging (MoO sub(4)) sup(2-) and (Mo sub(8) O sub(26)) sup(4-) ligands

Abstract

Hydrothermal synthesis, crystal structure and properties of a new heterometallic coordination polymer [(VO(terpy)) sub(4)(MoO sub(4)) sub(2)(Mo sub(8) O sub(26))].2H sub(2) O (1) (terpy = 2,2';6',2"-terpyridine) are reported. Compound 1 contains two crystallographically unique vanadium(IV) atoms, bonded to a terminal oxido ligand and further coordinated to a terpy ligand. The three N atoms of terpy occupy the meridional sites of a distorted {VN sub(3) O sub(3)} octahedron. A Gamma-octamolybdate (Mo sub(8) O sub(26)) sup(4-) located on an inversion centre and a tetraoxidomolybdate (MoO sub(4)) sup(2-) function as bridging ligands. The mu sub(3)-bridging tridentate binding of (MoO sub(4)) sup(2-) leads to the formation of a {V sub(4)Mo sub(2) O sub(12)} sup(4+) cationic unit consisting of an eight-membered heterometallic {Mo sub(2) V sub(2) O sub(4)} ring with protruding oxidovanadium handles. A pair of {V sub(4) Mo sub(2) O sub(12)} sup(4+) units are bridged by the centrosymmetric (Mo sub(8) O sub(26))sup(4-) ligand, resulting in the formation of an infinite chain of alternating {V sub(4) Mo sub(2) O sub(12)} sup(4+) cations and (Mo sub(8) O sub(26)) sup(4-) anions.