Synthesis and Characterization of Two Novel, Mono‐Lacunary Dawson Polyoxometalate‐Based, Water‐Soluble Organometallic Ruthenium(<scp>II</scp>) Complexes: Molecular Structure of [{(C₆H₆)Ru(H₂O)}(α₂‐P₂W₁₇O₆₁)]^8–

Abstract

Abstract The synthesis and structural characterization of a novel class of mono‐lacunary Dawson polyoxometalate‐(POM‐)based, water‐soluble organometallic complexes, which are expected to be effective homogeneous oxidation catalyst precursors in water, is described. The organometallic complexes K 8 [{(C 6 H 6 )Ru(H 2 O)}(α 2 ‐P 2 W 17 O 61 )] · 12H 2 O ( 1 ) and K 8 [{( p ‐cymene)Ru(H 2 O)}(α 2 ‐P 2 W 17 O 61 )] · 16H 2 O ( 2 ) were successfully prepared by direct reactions of the mono‐lacunary Dawson POM K 10 [α 2 ‐P 2 W 17 O 61 ] · 19H 2 O with the organometallic precursors [(C 6 H 6 )RuCl 2 ] 2 and [( p ‐cymene)RuCl 2 ] 2 , respectively, in aqueous media and characterized by complete elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), and FT‐IR and solution ( 1 H, 13 C, 31 P, and 183 W) NMR spectroscopy. The molecular structure of [{(C 6 H 6 )Ru(H 2 O)}(α 2 ‐P 2 W 17 O 61 )] 8– ( 1a ), in which the binding of the cationic organometallic group {(C 6 H 6 )Ru(H 2 O)} 2+ occurs through two oxygen atoms of the four available oxygen atoms in the mono‐lacunary site of the POM, resulting in overall C 1 symmetry, was successfully determined by single‐crystal X‐ray analysis. Interestingly, the hydrophilicity of the organometallic precursors is greatly enhanced by binding to a mono‐lacunary Dawson POM with higher hydrophilicity. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2006)