0000000000700965

AUTHOR

Fabiano Visentin

showing 3 related works from this author

Mechanism of aminocarbene formation by nucleophilic attack on isocyanide ligands in platinum(II)2-pyrazyl and 4-pyridyl complexes

1997

Abstract The reactions of 2-pyrazyl and 4-pyridyl isocyanide complexes [Pt(CNC 6 H 11 )(C 4 H 3 N 2 - C 2 )(dppe)ClO 4 and [Pt(CNC 6 H 11 )(C 5 H 4 N- C 4 ) (dppe)]ClO 4 ( 1 ) with amines involving the formation of aminocarbene derivatives have been studied kinetically in 1,2-dichloroethane by UV—VIS techniques. The kinetics obey the simple second-order rate law rate = k 2 [ 1 ][amine]. Low activation enthalpies and highly negative activation entropies for the k 2 term are observed. A mechanism is proposed involving direct nucleophilic attack of the amine on the isocyanide carbon with concomitant proton transfer from the amine to the isocyanide nitrogen assisted by the heterocyclic nitrogen…

ProtonChemistryLigandIsocyanideOrganic ChemistryKineticschemistry.chemical_elementPhotochemistryBiochemistryMedicinal chemistryNitrogenInorganic Chemistrychemistry.chemical_compoundNucleophileMaterials ChemistryAmine gas treatingPhysical and Theoretical ChemistryPlatinum
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Organometallic nucleophiles.A mechanistic study of halide displacement at saturated carbon by 2- and 4-pyridyl complexes of palladium (II) and platin…

1996

Abstract The reactions of the 2- and 4-pyridyl complexes [MX(C 5 H 4 N C n )(dppe)] and trans -[MX(C 5 H 4 N C n )(PPh 3 ) 2 ] (M  Pd, Pt; X  Cl, Br; n = 2, 4)- involving halide displacement from the organic halides XCH 2 R (X  Cl, Br; R  CN, Ph, CH  CH 2 ) by the pyridyl nitrogen have been studied kinetically by conductivity in acetone or acetonitrile at 25°C. The kinetic data fit the second-order rate law rate k 2 [XCH 2 R][complex], in agreement with an S N 2 process at saturated carbon. The higher rates are displayed by the 2-pyridylplatinum derivatives with X  Br in both the metal complex and the organic halide. The higher nucleophilic power of the 2-pyridyl complexes compare…

Organic ChemistryInorganic chemistrySubstituentchemistry.chemical_elementHalideBiochemistryMedicinal chemistryInorganic Chemistrychemistry.chemical_compoundNucleophilechemistryPyridineMaterials ChemistryReactivity (chemistry)Physical and Theoretical ChemistryAcetonitrileCoordination geometryPalladium
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Mechanism of oxidative allyl transfer from allylic ammonium cations to palladium(0) α-diimine complexes

1996

Abstract The palladium(0) complex [Pd(η2-fn)(NN′)] (1, fn = fumaronitrile; NN′ = C5H4N-2-CH=NC6H4OME-4) reacts slowly and reversibly with A +  CH 2  CH=CH 2 (2a, A = NEt 3 ; 2 b , A = C 5 H 5 N ) to yield the cationic η3-allypalladium(II) derivative [ Pd (η[ 3 - C 3 H 5 )( N  N ′)] + (3) the free amine A and fn. The equilibrium constant Ke is (2.6 ± 0.1) × 10−3 for 2a and 1.0 ± 0.4 for 2b. Kinetic studies of these oxidative allyl-transfer reactions show that the rates increase with increasing concentration of 2 and with decreasing concentration of fn. A stepwise mechanism is proposed which involves slow and reversible displacement of fn by 2 to give a labile intermediate [ Pd (η 2 - CH…

Allylic rearrangementOrganic ChemistryCationic polymerizationchemistry.chemical_elementPhotochemistryBiochemistryMedicinal chemistryInorganic ChemistrychemistryNucleophileIntramolecular forceMaterials ChemistryAmine gas treatingPhysical and Theoretical ChemistryEquilibrium constantDiiminePalladiumJournal of Organometallic Chemistry
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