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The cationic chloro complexes [(arene)Ru(H2N∩NH2)Cl]+ (1: arene = C6H6; 2: arene = p-MeC6H4iPr; 3: arene = C6Me6) have been synthesised from the corresponding arene ruthenium dichloride dimers and enantiopure (R,R or S,S) trans-1,2-diaminocyclohexane (H2N∩NH2) and isolated as the chloride salts. The compounds are all water-soluble and, in the case of the hexamethylbenzene derivative 3, the aqua complex formed upon hydrolysis [(C6Me6)Ru(H2N∩NH2)OH2]2+ (4) could be isolated as the tetrafluoroborate salt. The molecular structures of 3 and 4 have been determined by single-crystal X-ray diffraction analyses of [(C6Me6)Ru(H2N∩NH2)Cl]Cl and [(C6Me6)Ru(H2N∩NH2)OH2][BF4]2. Treatment of [Ru2 (arene) 2Cl4] with the monotosylated trans-1,2-diaminocyclohexane derivative (TsHN∩NH2) does not yield the expected cationic complexes, analogous to 1-3 but the neutral deprotonated complexes [(arene)Ru(TsN∩NH2)Cl] (5: arene = C6H6; 6: arene = p-MeC6H4iPr; 7: arene = C6Me6; 8: arene = C6H5COOMe). Hydrolysis of the chloro complex 7 in aqueous solution gave, upon precipitation of silver chloride, the corresponding monocationic aqua complex [(C6Me6)Ru(TsHN∩NH2)(OH2)]+ (9) which was isolated and characterised as its tetrafluoroborate salt. The enantiopure complexes 1-9 have been employed as catalysts for the transfer hydroge

The monocationic chloro complexes containing chelating 1,10-phenanthroline (phen) ligands [(arene)Ru(N∩N)Cl] + (1: arene = C6H6, N∩N = phen; 2: arene = C6H6, N∩N = 5-NO2-phen; 3: arene = p-MeC6H4Pri, N∩N = phen; 4: arene = p-MeC6H4Pri, N∩N = 5-NO2-phen; 5: arene = C6Me6, N∩N = phen; 6: arene = C6Me6, N∩N = 5-NO2-phen; 7: arene = C6Me6, N∩N = 5-NH2-phen) have been prepared and characterised as the chloride salts. Hydrolysis of these chloro complexes in aqueous solution gave, upon precipitation of silver chloride, the corresponding dicationic aqua complexes [(arene)Ru(N∩N)(OH2)]2+ (8: arene = C6H6, N∩N = phen; 9: arene = C6H6, N∩N = 5-NO2-phen; 10: arene = p-MeC6H4Pri, N∩N = phen; 11: arene = p-MeC6H4Pri, N∩N = 5-NO2-phen; 12: arene = C6Me6, N∩N = phen; 13: arene = C6Me6, N∩N = 5-NO2-phen; 14: arene = C6Me6, N∩N = 5-NH2-phen), which have been isolated and characterised as the tetrafluoroborate salts. The catalytic potential of the aqua complexes 8–14 for transfer hydrogenation reactions in aqueous solution has been studied: complexes 12 and 14 catalyse the reaction of acetophenone with formic acid to give phenylethanol and carbon dioxide with turnover numbers around 200 (80 °C, 7 h). In the case of 12, it was possible to observe the postulated hydrido complex [(C6Me6)Ru(phen)H]+ (15) in the reaction with sodium borohydride; 15 has been ch

The nicotinamide coenzyme NADH, consumed in enantioselective reduction of ketones catalysed by alcohol dehydrogenases, needs to be regenerated in order to maintain enzymatic activity. We therefore studied the catalytic potential of the cationic complexes [(η5-C5Me5)Rh(N∩N)Cl]+ (1: N∩N = 1,10-phenanthroline; 2: N∩N = 5-nitro-1,10-phenanthroline; 3: N∩N = 5-amino-1,10-phenanthroline), [(η5-C5Me5)Ir(N∩N)Cl]+ (4: N∩N = 5-nitro-1,10-phenanthroline) and [(η6-C6Me6)Ru(N∩N)Cl]+ (5: N∩N = 5-nitro-1,10-phenanthroline), isolated as the water-soluble chloride salts, for transfer hydrogenation of NAD+ to give NADH in aqueous solution. The best results were obtained with rhodium complex 1, which gave catalytic turnover frequencies up to 2000 h-1 in aqueous solution at pH 7 and 60 °C with sodium formate as the hydrogen source. When this NADH-regenerating catalytic system is combined with NADH-dependent enzymes, it is possible to chemoenzymatically reduce prochiral ketones such as acetophenone or 4-phenylbutan-2-one with high enantioselectivity. Combination of horse liver alcohol dehydrogenase (HLADH) or alcohol dehydrogenase from Rhodococcus sp. (S-ADH) with 1/formate as the NADH-regenerating system resulted in ee values up to 98 %, depending on the nature of the substrate and the enzyme. In order to explain the different catalytic activities, the electrochemical behaviour of complexes 1-5 has been studied.

The mononuclear cations [(η5-C5Me5)RhCl(bpym)]+ (1), [(η5-C5Me5)IrCl(bpym)]+ (2), [(η6-p-PriC6H4Me)RuCl(bpym)]+ (3) and [(η6-C6Me6)RuCl(bpym)]+ (4) as well as the dinuclear dications [{(η5-C5Me5)RhCl}2 (bpym)]2+ (5), [{(η5-C5Me5)IrCl}2 (bpym)]2+ (6), [{(η6-p-PriC6H4Me)RuCl}2 (bpym)]2+ (7) and [{(η6-C6Me6)RuCl}2 (bpym)]2+ (8) have been synthesised from 2,2′-bipyrimidine (bpym) and the corresponding chloro complexes [(η5-C5Me5)RhCl2]2, [(η5-C5Me5)IrCl2]2, [(η6-PriC6H4Me)RuCl2]2 and [(η6-C6Me6)RuCl2]2, respectively. The X-ray crystal structure analyses of [3][PF6], [5][PF6]2, [6][CF3SO3]2 and [7][PF6]2 reveal a typical piano-stool geometry around the metal centres; in the dinuclear complexes the chloro ligands attached to the two metal centres are found to be, with respect to each other, cis oriented for 5 and 6 but trans for 7. The electrochemical behaviour of 1–8 has been studied by voltammetric methods. In addition, the catalytic potential of 1–8 for transfer hydrogenation reactions in aqueous solution has been evaluated: All complexes catalyse the reaction of acetophenone with formic acid to give phenylethano

A new family of nine cationic organometallic aqua complexes of the type [(arene)Ru(RSO2NNH2)(OH2)]+ (1–9), containing chiral N,N-chelating ligands, has been synthesised and isolated as the tetrafluoroborate salts, which are water-soluble and stable to hydrolysis. The enantiopure complexes 1–9 catalyse the transfer hydrogenation of prochiral aryl ketones and imines in aqueous solution to give the corresponding alcohols and amines with good conversion and enantioselectivity. This method gives an environmentally friendly access, for instance, to isoquinoline alkaloids by asymmetric catalysis in water.

In the centrosymmetric dinuclear title complex, [RuCl2 (η6-C6H6)]2•2CHCl3 or [Ru2Cl4(C6H6)2]•2CHCl3, accessible from RuCl3.nH2O and 1,3-cyclohexadiene, the benzene ligands are involved in slipped-parallel - stacking interactions with neighbouring molecules, thus forming one-dimensional polymeric chains.

The electrochemical properties of cationic complexes [(η6-arene)Ru(N ∩ N)Cl]Cl (arene/N ∩ N = C6H6/1,10-phenanthroline (1), p-MeC6H4Pri/1,10-phenanthroline (2), C6Me6/1,10-phenanthroline (3), C6Me6/5-NO2-1,10-phenanthroline (4), and C6Me6/5-NH2-1,10-phenanthroline (5)) were studied by cyclic voltammetry in order to rationalize catalytic activity in transfer hydrogenation of the respective aqua complexes [(η6-arene)Ru(N ∩ N)(OH2)](BF4)2 (6–10). Complexes 1–5 were chosen because the ‘true’ catalysts 6–10 are unstable under the conditions of the measurement. The electrochemical behaviour of 1–5 in acetonitrile solution is rather complicated due to consecutive and parallel chemical reactions that accompany electron transfer processes. Nonetheless, interpretation of the electrochemical data allowed to assess the influence of the structure and substitution on the redox and catalytic properties: the catalytic ability correlates with the reduction potentials, indicating the decisive role of the η6-arene ring directly bonded to the catalytic centre (Ru).

The enantiomerically pure iridium title complex, [Ir(C/sub>13H19N2O2S)(C10H15)Cl]•CHCl3, has the Ir atom in the S configuration, with a distorted octahedral geometry.

Le but de ce travail de thèse a été de développer des complexes arèneruthénium, cyclopentadiènyl-rhodium et -iridium hydrosolubles à ligands N,Ndonneurs et de les utiliser en tant que catalyseurs en solution aqueuse. La mise au point de systèmes catalytiques efficaces pour des réactions en milieu aqueux, s’inscrivant dans le concept de « chimie verte », revêt un intérêt tout particulier. Au cours de cette thèse, des complexes organométalliques hydrosolubles de ruthénium, de rhodium et d’iridium se sont révélés être des candidats idéaux pour des applications catalytiques en solution aqueuse. Ainsi, le complexe [(C6Me6)Ru(5-nitro-1,10-phénanthroline)(OH2)]2+ a montré une activité catalytique de 32 h-1 pour le transfert hydrogénant de l’acétophénone. Par ailleurs, utilisé comme catalyseur de régénération du NADH, [(C5Me5)Rh(1,10-phénanthroline)Cl]+ en combinaison avec une alcool déshydrogénase a permis l’obtention d’alcools chiraux avec des excès énantiomériques allant jusque 98 %. De plus, l’introduction d’un ligand chiral a permis, grâce à l’utilisation en particulier du complexe [(C6Me6)Ru((R,R)-N-tosyl-1,2-diaminocyclohexane)(OH2)]2+, d’obtenir des excès énantiomériques allant jusqu’à 94 % et des activités catalytiques de 45 à 50 h-1 pour l’hydrogénation par transfert de cétones et d’imines aryliques.

The cationic chloro complexes [(arene)Ru(H2N∩NH2)Cl]+ (1: arene = C6H6; 2: arene = p-MeC6H4iPr; 3: arene = C6Me6) have been synthesised from the corresponding arene ruthenium dichloride dimers and enantiopure (R,R or S,S) trans-1,2-diaminocyclohexane (H2N∩NH2) and isolated as the chloride salts. The compounds are all water-soluble and, in the case of the hexamethylbenzene derivative 3, the aqua complex formed upon hydrolysis [(C6Me6)Ru(H2N∩NH2)OH2]2+ (4) could be isolated as the tetrafluoroborate salt. The molecular structures of 3 and 4 have been determined by single-crystal X-ray diffraction analyses of [(C6Me6)Ru(H2N∩NH2)Cl]Cl and [(C6Me6)Ru(H2N∩NH2)OH2][BF4]2. Treatment of [Ru2 (arene) 2Cl4] with the monotosylated trans-1,2-diaminocyclohexane derivative (TsHN∩NH2) does not yield the expected cationic complexes, analogous to 1-3 but the neutral deprotonated complexes [(arene)Ru(TsN∩NH2)Cl] (5: arene = C6H6; 6: arene = p-MeC6H4iPr; 7: arene = C6Me6; 8: arene = C6H5COOMe). Hydrolysis of the chloro complex 7 in aqueous solution gave, upon precipitation of silver chloride, the corresponding monocationic aqua complex [(C6Me6)Ru(TsHN∩NH2)(OH2)]+ (9) which was isolated and characterised as its tetrafluoroborate salt. The enantiopure complexes 1-9 have been employed as catalysts for the transfer hydroge

The monocationic chloro complexes containing chelating 1,10-phenanthroline (phen) ligands [(arene)Ru(N∩N)Cl] + (1: arene = C6H6, N∩N = phen; 2: arene = C6H6, N∩N = 5-NO2-phen; 3: arene = p-MeC6H4Pri, N∩N = phen; 4: arene = p-MeC6H4Pri, N∩N = 5-NO2-phen; 5: arene = C6Me6, N∩N = phen; 6: arene = C6Me6, N∩N = 5-NO2-phen; 7: arene = C6Me6, N∩N = 5-NH2-phen) have been prepared and characterised as the chloride salts. Hydrolysis of these chloro complexes in aqueous solution gave, upon precipitation of silver chloride, the corresponding dicationic aqua complexes [(arene)Ru(N∩N)(OH2)]2+ (8: arene = C6H6, N∩N = phen; 9: arene = C6H6, N∩N = 5-NO2-phen; 10: arene = p-MeC6H4Pri, N∩N = phen; 11: arene = p-MeC6H4Pri, N∩N = 5-NO2-phen; 12: arene = C6Me6, N∩N = phen; 13: arene = C6Me6, N∩N = 5-NO2-phen; 14: arene = C6Me6, N∩N = 5-NH2-phen), which have been isolated and characterised as the tetrafluoroborate salts. The catalytic potential of the aqua complexes 8–14 for transfer hydrogenation reactions in aqueous solution has been studied: complexes 12 and 14 catalyse the reaction of acetophenone with formic acid to give phenylethanol and carbon dioxide with turnover numbers around 200 (80 °C, 7 h). In the case of 12, it was possible to observe the postulated hydrido complex [(C6Me6)Ru(phen)H]+ (15) in the reaction with sodium borohydride; 15 has been ch