Coordination of α,β-unsaturated aldehydes on d6 Ru and Rh complexes: A DFT study

The coordination of α,β-unsaturated aldehydes on Ru and Rh complexes has been investigated. On the ML4 RuH2(PH3)2 fragment, all aldehydes are η4 coordinated. On the ML5 RuH2(PH3)3 fragment, the η2CC coordination is the most stable even if the η2CO one can become competitive with bulky ligands and substituted aldehydes. On RhH2Cl(PH3)2 the η2CO coordination does not exist and the most stable one is η1O.