Grafting {Cp*Rh}2+ on the surface of Nb and Ta Lindqvist-type POM†
Abstract
New hybrid POM based on Lindqvist-type polyoxometalates [M6O19]8− (M = Nb, Ta) and organometallic fragment {Cp*Rh}2+ have been isolated and characterized. X-ray quality crystals of K4[(Cp*Rh)2Nb6O19]·20H2O (1) and Cs4[(Cp*Rh)2Ta6O19]·18H2O (2) were obtained from solutions with {Cp*Rh} : [M6O19]8− stoichiometry 2 : 1. The solution behavior of the hybrid polyoxoanions was studied with ESI-MS and 1H DOSY NMR. Amongst the poorly investigated chemistry of polyoxotantalates, complex 2 is the first complex bearing a grafted organometallic fragment. The formation of 1 : 1 complexes was detected by ESI-MS techniques.