Dehydration, hydration and substitution reactions of the hydrido acetylide complexes HRu3(CO)(9){C2CR(OH)R '}. X-ray structures and NMR fluxionality of HRu3(CO)(7)(dppm) {C2CMe(OH)Ph} and HRu3(CO)(7)(dppm) {C2C(=CH2)Ph}

摘要

The complexes HRu3(CO)(9){C2CR(OH)R'} (1) have been obtained by reaction, in hydrocarbon solution, of Ru,(CO),, with propargyl alcohols of general formula HC,CR(OH)R'. In contrast, reaction of Ru-3(CO)(12) with the alcohols (R = R' = Me, R = Me, R' = Ph) in CH3OH/KOH solution leads to formation of the corresponding allenylidene complexes HRu3(CO)(9){HC2C(R)R'} (2). The H-1 and C-13 NMR fluxional behaviour of the complexes are discussed. The acetylide clusters are stable species and lose water only under drastic conditions (i.e. in the presence of strong acids or on TLC silica), to form vinylacetylide or allenylidene derivatives according to the nature of the acetylide substituents. The reverse hydration reactions occur with some difficulty. The chiral cluster HRu3(CO)(9){C2CMe(OH)Ph} (1d) reacts with dppm forming the "bridged" complex HRu3(CO)(7)(dppm){C2CMe(OH)Ph} (3) which exists bath in the solid state and in solution as two diastereoisomeric pairs of enantiomers. The X-ray structure and the NMR fluxionality of complex 3 is discussed. Protonation of complex 3 leads to loss of water and formation of HRu3(CO)(7)(dppm){C2C(=CH2)Ph} (4), the X-ray structure of which is also discussed. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 49]