Résultat de la recherche
Tetra- and hexanuclear cage molecules based on diruthenium tetracarbonyl sawhorse units: Synthesis and molecular structure of [{Ru2(CO)4 (PPh3)2}2 (O2CCH2CO2)2] and [{Ru2(CO)4 (PMe3)2}3 (O2CC6H4CO2)3]
The thermal reaction of Ru3 (CO)12 with malonic acid, followed by the addition of the corresponding ligand, yields the tetranuclear ruthenium complexes [{Ru2 (CO) 4L2}2 (O2CCH2CO2)2] (L = PPh3: 1, L = 3,5-Me2NC5H3: 2), while the reaction of Ru3 (CO)12 with terephthalic acid, followed by the addition of the corresponding ligand, gives rise to the formation of the hexanuclear ruthenium complexes [{Ru2 (CO)4L2}3 (O2CC6H4CO2)3] (L = PMe3: 3, L = 3,5-Me2NC5H3: 4). The single-crystal X-ray structure analyses for 1 and 3, reveal both cages to consist of Ru2 (CO)4 sawhorse units, 1 being a molecular loop, while 3 is a molecular triangle.
Dinuclear ruthenium sawhorse-type complexes containing carboxylato bridges and ferrocenyl substituents: Synthesis and electrochemistry
The ferrocenyl-containing diruthenium complexes [Ru2(CO)4(μ2-η2-OOCFc)2L2] (Fc = ferrocenyl, fc = ferrocen-1,1′-diyl; 1: L = NC5H4–COOC6H4–OC10H21, 2: L = NC5H4–COOC6H4–OC16H33, 3: L = NC5H4–OOC–fc–C12H25) and [Ru2(CO)4(μ2-η2-OOC6H5)2(NC5H4–OOC–fc–C12H25)2] (4) have been synthesized from Ru3(CO)12, ferrocene carboxylic or benzoic acid and the corresponding pyridine derivative. The synthesis of the new pyridine derivative NC5H4–OOC–fc–C12H25 used for the preparation of 3 and 4 is also reported. Complexes 1–4 posses a so-called sawhorse structure consisting of the Ru2(CO)4 backbone and two bridging carboxylato ligands, while the coordination sphere around the ruthenium atoms is completed by the pyridine-derived ligands bonded in the axial positions. The electrochemical behavior of 1–4 and their known analogues [Ru2(CO)4(μ2-η2-OOCFc)2L2] (5: L = NC5H5, 6: L = P(C6H5)3, 7: L = NC5H4–OOCFc) has been studied by voltammetry on rotating disc electrode and by cyclic voltammetry.
Ru2(CO)4(OOCR)2(PPh3)2 sawhorse-type complexes containing μ2-η2-carboxylato ligands derived from biologically active acids
The thermal reaction of Ru3(CO)12 with the biologically active acids acetyl salicylic acid (Aspirin), α-methyl-4-(isobutyl)phenylacetic acid (Ibuprofen) and 3α,7α,12α-trihydroxy-5β-cholanic acid (cholic acid) in refluxing tetrahydrofuran, followed by addition of triphenylphosphine, gives the dinuclear complexes Ru2 (CO) 4(OOCR)2(PPh3)2 (1: R = C6H4-2-OCOMe, 2: R = CHMe-C6H4-4-Bui, 3: C23H39O3). The single-crystal structural analysis of 1 and 2 reveals a dinuclear Ru2(CO)4 sawhorse structure, the diruthenium backbone being bridged by the carboxylato ligands, while the two phosphine ligands occupy the axial positions at the ruthenium atoms. However, chiral carbon atoms in the carboxylic acid undergo racemisation during the thermal reaction.