Syntheses, structure characterisation and X-ray studies of some mono, di- and tri-substituted cluster complexes of Ru3(CO)12 substituted by bulky fluorinated phosphine ligands

Abstract

Five trinuclear substituted complexes of the type Ru3(CO)11L, Ru3(CO)10L2 and Ru3(CO)9L3 were synthesised by the reaction of Ru3(CO)12 with fluorine substituted phosphine ligands, {P(C6H4F-m)3 and P(C6H4F-p)3}, using the radical anion catalysed method. The structures of the resulting clusters were elucidated by means of elemental analyses and spectroscopic methods, which included IR, 1H, 13C and 31P NMR spectroscopy. X-ray crystallographic studies of four of the complexes were carried out. In all the complexes, the ligand occupies an equatorial position due to steric reasons, and coordination of the ligand is observed only at the phosphorus atom. In the two monosubstituted complexes, Ru3(CO)11P(C6H4F-m)3 and Ru3(CO)11P(C6H4F-p)3, the effect of substitution resulted in an increase in the Ru–Ru distances. Out of the three Ru–Ru bonds, the one which is cis to the ligand is noticeably longer than the other two. The asymmetric unit of the disubstituted complex Ru3(CO)10{P(C6H4F-p)3}2 is composed of two molecules, A and B. As expected, the two phosphorus ligands are equatorially bonded to two different ruthenium atoms. The asymmetric unit of the trisubstituted complex is composed of one molecule of Ru3(CO)9{P(C6H4F-m)3}3 and one disordered solvent molecule. The structure consists of one triangular ruthenium complex in which each of the phosphorus ligands is equatorially bonded to three different ruthenium atoms. In the structure, disorder of the fluorine atoms is observed. Bond parameters, especially bond lengths and bond angles, are correlated to the structure and also are compared with the literature data of similar compounds.