Synthesis and structural characterization of a new heterometallicmolybdate coordination polymer based on a mu sub(3)-bridging amino alcohol

Abstract

The reaction of Na sub(2) MoO sub(4).2H sub(2) O with 2-amino-2-(hydroxymethyl)propane-1,3-diol (LH) in water at room temperature results in the formation of the heterometallic coordination polymer [Mo sub(2) O sub(6) L sub(2)(Na sub(2)(H sub(2) O) sub(4))].2H sub(2) O 1 (L = 2-amino-3-hydroxy-2-(hydroxymethyl)propan-1-olato). The structure of 1 consists of a neutral (Mo sub(2) O sub(6)) unit located on an inversion center. The Mo atoms exhibit hexa-coordination and are bonded to two terminal and two bridging oxido ligands, an alkoxide oxygen and the amine N atoms of an anionic ligand L- resulting in the formation of an edge-sharing {Mo sub(2) O sub(8) N sub(2)} bioctahedron. The Na sup(+) cations of a centrosymmetric bis(mu 2-aqua)-bridged (Na sub(2)(H sub(2) O) sub(4)) sup(2+) unit are penta-coordinated and bonded to two symmetry related L sup(-) ligands via the oxygen atoms of their OH groups. The mu 3-bridging tetradentate binding mode of L sup(-) results in the formation of a two-dimensional heterometallic coordination polymer. The constituents of 1 viz. (Mo sub(2) O sub(6)), (L) sup(-), (Na sub(2)(H sub(2) O) sub(4)) sup(2+) and lattice water molecules are interlinked with the aid of three varieties of hydrogen bonding interactions. The corresponding tungstate reported recently has been obtained through a similar synthetic protocol and is isostructural.