A new Lindqvist-type hexamolybdate cluster functionalized with the pi-donor ligand 4-bromo-2,6-dimethylphenylimido. Spectroscopic, electrochemical and structural studies

Abstract

A new ionic organic-inorganic hybrid complex of formula (n-Bu4N)(2) [Mo6O18(NR)]center dot 1/2Me(2)CO, R = -C6H2-2,6-Me-2-4-Br, (n-Bu4N)(2)[1]center dot 1/2Me(2)CO, has been prepared in acetonitrile by reacting tetrabutyl ammonium alpha-octamolybdate, (n-Bu4N)(4)[(alpha-Mo8O26], with 2,6-dimethyl-4-bromoaniline hydrochloride, 2,6-Me-2- 4-Br-C6H2NH2 center dot HCl using N,N'-dicyclohexylcarbodiimide, (C6H11)N=C=N(C6H11), as dehydrating agent. This complex, formulated as (n-Bu4N)(2)[1]center dot 1/2Me(2)-CO, contains a C-Br group which can be functionalized for constructing novel hybrid materials. The complex was fully characterized by IR, UV-Vis, H-1- and C-13-NMR spectroscopies, and authenticated by single crystal X-ray diffraction analysis. The asymmetric unit contains two crystallographically independent anions, [1](2-), differing by the orientation of the phenyl ring relative to the hexamolybdate skeleton, and one molecule of acetone. Both molecules differ in the angles Mo(1)- N(1)-C(1) = 172.2(6) and Mo(7)-N(2)-C(9)= 175.6(6)degrees. These angles, near to 180 degrees, indicate the presence of a Mo N triple bond.