The preparation and characterisation of cationic formyl complexes of ruthenium(II); crystal and molecular structure of the complex trans-bis[1,2-bis(diphenylphosphino)ethane-PP′]carbonyl(deuterioformyl)ruthenium(II) hexafluoroantimonate–dichloromethane(1/1)
Abstract
Reactions of the complexes trans-[Ru(CO)2(dppe)2][SbF6]2(dppe = Ph2PCH2CH2PPh2) or cis-[Ru(CO)2(dppm)2][SbF6]2(dppm = Ph2PCH2PPh2) with [Na{HB(OEt)3}] or [K{HB(OPri)3}] afford [Ru(CHO)(CO)(P–P)2][SbF6](P–P = dppe or dppm), without change of stereochemistry, in high yield. [Li(HBEt3)] gives [Ru(CHO)(CO)(P–P)2][BEt4], the counter ion being introduced as an impurity in [Li(HBEt3)]. [Li(DBEt3)] gives [Ru(CDO)(CO)(P–P)2][SbF6] and a 13C labelled analogue is prepared from trans-[Ru(13CO)2(dppe)2][SbFe6]2. The complexes are sufficiently stable in the solid state and in solution at –30 °C for full characterisation by spectroscopic means, one notable feature being the appearance of two peaks in the νC-H region of the i.r. spectrum of cis-[Ru(CHO)(CO)(dppm)2]Y(Y =[SbF6] or [BEt4]) attributable to Fermi resonance between pure νC-H and 2δC-H. trans-[Ru(CDO)(CO)(dppe)2][SbF6]·CH2Cl2 is orthorhombic, space group Pn21a(Pna21, no. 33), with a= 22.364(1), b= 20.244(2), c= 11.944(1)Å, and Z= 4. The structure was obtained from 1 752 observed intensities measured on an automatic diffractometer and refined to an R value of 0.084. The main features of interest are a long Ru–C (2.09 Å) bond and a Ru–C–O angle of 133°.