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Abstract  

A series of (o-alkylaminophenyl)diphenylphosphine ligands (P–N ligands) containing different alkyl carbon numbers or amino groups have been synthesized and characterized by IR and NMR (1H, 13C, 31P). The rhodium complexes ligated with P–N ligands in the hydroformylation of 1-hexene showed a considerable enhancement with the addition of water. NMR characterization studies suggested that the addition of water would engage in hydrogen bonding to the nitrogen atom of the coordinated P–N ligand, inhibiting the internal Rh–N interaction and generating more of the active unsaturated Rh-species that could react with 1-hexene to start the hydroformylation.

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Abstract  

An MCM-41-supported mercapto rhodium complex [MCM-41–SH–Rh] was conveniently synthesized from commercially available and cheap γ-mercaptopropyltriethoxysilane via immobilization on MCM-41, followed by reacting with rhodium chloride. It was found that the title complex is an efficient catalyst for the hydrosilylation reaction of olefins with triethoxysilane and can be reused several times without noticeable loss of activity.

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polymerization reactions. Furthermore, it is necessary to decrease the olefin quantities due to standard regulations [ 4 ]. Traditionally, rhodium complexes have been used as catalysts in hydroformylation reactions, mostly using ligands as phosphines, phosphites

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Abstract  

105Rh[1,5,9,13-tetrathiacyclohexadecane-3,11-diol] is a promising drug precursor for targeted radiotherapy. Nevertheless, the axial position of chloride ions in the complex structure and their weak binding to rhodium centre, due to HSAB concept, make such a complex subject to modifying action of certain sulphuric ligands, like human plasma thiol antioxidants: glutathione and cysteine. Experiments were performed with both radioactive 105Rh and inactive rhodium. The complexation of rhodium with 1,5,9,13-tetrathiacyclohexadecane-3,11-diol (16S4diol) resulted in three distinct peaks seen on UV, radiometric and MS chromatograms. The substitution of chlorides was noted in over 80% of 105[Rh(16S4diol)Cl2]+ units after incubation with glutathione, and less than 10% of complex units after incubation with cysteine (24 h, 37 °C). Reaction of 105[Rh(16S4diol)Cl2]+ with 1,8-octandithiol and 1,9-nonandithiol resulted in disappearance of the complex peak and occurrence of two new peaks. Product of RhCl3 and 16S4diol reaction is a mixture of three distinct forms having different number of chlorine atoms. Our in vitro experiments suggest that the substitution of axial chlorides with glutathione and cysteine might also occur in vivo in human plasma. Glutathione shows higher reactivity than cysteine in replacement reaction. Axial positions in precursor might be effectively blocked by 1,8-octandithiol and 1,9-nonandithiol.

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was carried out by flash column chromatography. The column was packed with Silica gel 60 F from Fluka Chemie AG (Buchs, Switzerland); ethyl acetate and petroleum ether (boiling fraction 60–80 °C) were used as eluting solvents. Rhodium complexes were

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ensured the cooling of the reaction mixture before quenching it with HCl in a methanol solution, and taking samples for NMR analysis. The microreactor was filled with THF and cooled down to 0 °C. The rhodium complex (0.0215 mmol) and a certain

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suppose that the unknown phase ( X ) is the ammine rhodium complex [Rh(NH 3 ) 3 Br 3 ]. The processes of thermal decomposition of [Rh(NH 3 ) 5 Br][AuBr 4 ] 2 · n H 2 O in inert atmosphere can be described by Eq. 2 : 2 Fig. 4

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to the rhodium atom. The bent transition state structure leads to the same intermediate product as the linear/back transition state structure—a cationic five-coordinated rhodium complex and a free iodide ion. The displacement vector of the bent

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reaction by rhodium complexes . Polyhedron 15 7 1217 – 1219 10.1016/0277-5387(95)00365-7 . 26. Zhang , W , Loebach , JL , Wilson , SR , Jacobsen , EN 1990 Enantioselective epoxidation

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Journal of Thermal Analysis and Calorimetry
Authors: Hieronim Maciejewski, Izabela Dąbek, Ryszard Fiedorow, Michał Dutkiewicz, and Mariusz Majchrzak

.03.114 . 36. Marciniec , B , Maciejewski , H , Szubert , K , Kurdykowska , M . 2006 . Modification of (poly)siloxanes via hydrosilylation catalyzed by rhodium complex in ionic liquids . Monats Chem . 137 : 605

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