Oxidative Addition von Aldehyden und Schiffbasen an Ru 3 (CO) 12

Oxidative Addition of Aldehydes and Schiff Bases to Ru 3 (CO) 12 Aldehydes show a wide variation of their reactive behaviour towards Ru 3 (CO) 12 . Aliphatic and simple aromatic aldehydes form simple oxidative addition products Ru 3 (CO) 10 (μ‐H)(μ‐RC = O) ( 1 ) either not at all or in low yields as impure compounds, while under forcing conditions dinuclear ruthenium μ‐carboxylate complexes or the hydride H 2 Ru 4 (CO) 13 are formed. Electron‐rich aldehydes give good yields of cluster type 1 (R = p ‐MeOC 6 H 4 , p ‐Me 2 NC 6 H 4 , ferrocenyl). Schiff bases behave similarly, their oxidative addition products being Ru 3 (CO) 10 (μ‐H)(μ‐RC = NR′) ( 10 , R = C 6 H 5 , p ‐MeOC 6 H 4 , p ‐Me 2 NC 6 H 4 , R′ = C 6 H 5 , p ‐MeC 6 H 4 ). Of the ortho ‐substituted benzaldehydes, the methoxy compound produces clusters 6 and 7 resulting from aldehyde oxidative addition and aromatic ortho metalation. Salicylaldehyde and its p ‐tolylimine give the compounds Ru 3 (CO) 8 (μ‐η 2 ‐OC 6 H 4 CH = X) 2 ( 9, 11 , X = O, NC 6 H 4 Me) with a bridging phenolate and a terminally bound aldehydic O or Schiff base NR function. 3‐Pyridinecarbaldehyde reacts quickly with Ru 3 (CO) 12 to give products 8 derived from pyridine CH rather than aldehyde CH oxidative addition. The crystal structures of 9 and 11 were determined.