0000000000001128
AUTHOR
M. A. Ubeda
Synthesis, characterization and kinetics of the metallation of the intermediate compound to produce compound · (H2O) from Rh(II) tetraacetate
Abstract Photochemical irradiation of mixtures of [Rh2(μ-O2CCH3)4]·(HOCH3)2 and P(2-(CH3O)C6H4)Ph2 (POMe) in CH2Cl2 solution (1:1 molar ratio) yields quantitatively compound [ Rh 2 (μ- O 2 CCH 3 ) 3 ( O 2 CCH 3 )(η 2 - P (2-( CH 3 O ) C 6 H 4 ) Ph 2 ]·( H 2 O ) (1) containing a POMe acting as a chelating equatorial ( P ) axial ( O ) donor ligand. This compound undergoes intramolecular CH activation reaction at one of the phenyl rings in CHCl3 or CH3COOH/toluene solution at room temperature to form the monometallated compound [ Rh 2 (μ- O 2 CCH 3 ) 3 (μ-( C C 3 H 4 ) P (2-( CH 3 O C 6 H 4 ) Ph )]· ( H 2 O ) ( 2 ). The kinetics of the 1 → bd2 reaction have been studied in acid media (CH3CO…
Synthesis and crystal structure of {Rh2(O2CCH3)4·P(o-CH3OH6H4)Ph2}2. A novel dirhodium(II) monoadduct with intermolecular μ-oxo interactions
Abstract We have investigated the reaction of dirhodium tetraacetate with the phosphine P( o -CH 3 OH 6 H 4 )Ph 2 (P) under different experimental conditions. From these reactions we have been able to isolate the dirhodium tetraacetate phosphine mono-adduct. The crystal structure shows that in the solid state this compound forms a centrosymmetric dimer of the dimer, {Rh 2 (O 2 CCH 3 ) 4 ·P(0-CH 3 OC 6 H 4 )Ph 2 } 2 , in which we oxygen atom from one acetate group in one Rh 2 (O 2 CCH 3 ) 4 ·P unit is axially coordinating one Rh atom on another Rh 2 (O 2 CCH 3 ) 4 · P unit (Rh⋯) 2.347(3) A intermolecular versus Rh⋯O 2.455(3) A intermolecular), and vice versa. The RhRh bond distance is 2.414…
Synthesis of a New C3-Symmetric Tripodal P4-Tetradentate Ligand and Its Application to the Formation of Chiral Metal Complexes
A novel C3-symmetric tetradentate tripodal ligand with phosphorus as coordinating atoms has been synthesized in good yields. Its coordination ability through the four phosphorus atoms, three at the...
Rhodium (II) compounds with functionalized metalated phosphines as bridging ligands
Abstract The reaction of Rh2(O2CCH3)4 · 2CH3OH with the phosphine P(4-BrC6H4)2(C6H5), 2, results in the formation of the monometalated compound Rh2(O2CCH3)3[PC] · 2CH3CO2H (PC representing a metalated P(4-BrC6H4)2(C6H5)). The reaction involves selective metalation of the phosphine at one Br-substituted ring (12:1 isomer ratio). The reaction of Rh2(O2CCH3)3[(4-BrC6H3)P(4-BrC6H4)(C6H5)] · 2CH3CO2H, 4, with one additional mol of triphenylphosphine yields a mixture of two main stereoisomers Rh2(O2CCH3)2[(4-BrC6H3)P(4-BrC6H4)(C6H5)] [(C6H4)P(C6H5)2] · 2CH3CO2H, 5a and 5b, that were isolated as pure compounds. These two compounds were resolved in the corresponding M and P enantiomers as trifluoro…
Synthesis, Reactivity, and X-ray Crystallographic Characterization of Mono-, Di-, and Tetranuclear Palladium(II)-Metalated Species
The reactivity of the tetranuclear metallated palladium compound (Pd[mu 2-(C6H4)PPh2]Br)4 (1) with different ligands has been investigated with the aim of evaluating the influence of the entering ligand on the nature of the reaction products. The results confirmed the ability of the ligand [(C6H4)PPh2]- to expand a bridging [mu 2-] or a chelating [eta 2-] coordination mode, depending on the auxiliary ligands present in the complex. Bulky phosphines stabilize mononuclear species of formula (Pd[eta 2-(C6H4)PPh2]Br[P]), with a four-atom metallocycle, while small phosphines give dinuclear compounds. The molecular structures of three different metalated palladium compounds have been determined b…
Electrochemical chiral recognition by microparticle coatings of Pd complexes with bridging cyclometalated phosphines
Abstract The palladium(II) dinuclear complex with bridging cyclometalated phosphines, {Pd2[μ-(C6H4)PPh2]2(μ-O2CCH3)2} (Pd2L2), having a paddlewheel structure, is reversibly oxidized in CH2Cl2 to a dinuclear palladium(III) analogue via two successive one-electron steps. Solid state voltammetry of Pd2L2 in contact with aqueous electrolytes produce as one-electron oxidation with two competing mechanisms involving anion intercalation/anion binding between/to metal centres, chloride ions acting as inhibitors for the first pathway. R- and S-Pd2L2 produces a significant stereoselective electrocatalytic activity with respect to the oxidation of l - and d -glutamic acid in alkaline media.
Synthesis of Cyclometalated Rhodium(III) Complexes. Study of the Carbonyl Insertion Reactions into the Rh-C Bond of the Metalocycle
Abstract In this paper we report the preparation of new orthometalated rhodium(III) compounds of the formula Rh(oq)(AB)(PC), from Rh(oq)(Br)(PC)(H20), AB being a bidentade anionic ligand, oq= 8-oxyquinolate and PC = P(o-C6F4)Ph2. Their redox behaviour is also described. The reaction of Rh(Oq)(Br)(PC)(H20) [Oq = 5-Me-8-oxyquinolate (5-Meoq), 8-oxyquinolate] with carbon monoxide under pressure leads to expansion of the metalocycle ring by CO insertion into the Rh-C bond.