Oxidative Addition of Propargyl Halides, Chloroacetonitrile, and Ethyl Chloroacetate to a Dimethylplatinum(II) Complex: Kinetic and DFT Studies

Abstract

Oxidative addition reaction of propargyl halides, XCH 2 CCH (X = Cl, Br), with the platinum(II) complex [PtMe 2 (bipy)] (1), in which bipy = 2,2′-bipyridine, gave a mixture of the propargyl halide complex [PtXMe 2 (CH 2 C CH)(bipy)], (X = Cl, trans isomer 2a and cis isomer 2a′; X = Br, trans isomer 2b and cis isomer 2b′) and the allene complex [PtXMe 2 (CHCCH 2 )(bipy)], (X = Cl, trans isomer 3a and cis isomer 3a′; X = Br, trans isomer 3b and cis isomer 3b′). The reaction involving propargyl bromide followed second-order kinetics (first order in both reactants), while that involving propargyl chloride showed third-order kinetics (first order in 1, second order in ClCH 2 CCH) in acetone or benzene solvent. Similar reactions of chloroacetonitrile (ClCH 2 CN) and ethyl chloroacetate (ClCH 2 COOEt) reagents with complex 1 yielded [PtClMe 2 (CH 2 CN)(bipy)] ( 4) and [PtClMe 2 (CH 2 COOEt)(bipy)] (5), respectively, each as a mixture of cis and trans isomers, proceeding with second-order kinetics. Unpredictably, the reaction rates of complex 1 with propargyl bromide and chloroacetonitrile in benzene solvent are faster than those in acetone solvent. Consistent with our 1 H NMR experimental results, DFT studies showed that the cis addition products of allene tautomers (3a′,b′) are more stable than their corresponding trans isomers (3a,b).

Oxidative addition of 1,4‐dichloro‐2‐butyne to an organoplatinum complex: A new precursor for synthesis of ultrasmall Pt nanoparticles thin film at liquid/liquid interface as the electrocatalyst in methanol oxidation reaction

“…Kinetic study for the reaction of 1,4‐dichloro‐2‐butyne with organometallic [PtMe 2 (bipy)] complex, 1 , was investigated in acetone solvent. Disappearance of MLCT band at λ = 475 nm was followed by UV–Vis spectrometer . The reactions were carried out in the presence of excess amount of 1,4‐dichloro‐2‐butyne, therefor during a kinetic run, concentration of reagent was constant.…”

“…Kinetic studies of colorful diimine Pt (II) complexes are facile due to characteristic sharp metal‐to‐ligand charge transfer (MLCT) bands in the visible region . Recently, we have studied the oxidative addition reaction of allyl and propargyl halides to [PtMe 2 (bipy)] complex and unusual results including, third order kinetics were observed in oxidative addition reaction for the first time by our group …”

“…[15,16] Recently, we have studied the oxidative addition reaction of allyl and propargyl halides to [PtMe 2 (bipy)] complex and unusual results including, third order kinetics were observed in oxidative addition reaction for the first time by our group. [17,18] Decomposition of organometallic complexes in milder conditions provides a route for preparation of nanoparticles (NPs) with controllable size without using organic salts, oxides and halides. [19][20][21] Wide range of metal and metal oxide NPs such as Ru, Au, Rh, Pt, Fe, Ni, Pd, Cu, Co, ZnO, [21,22] bimetallic NPs such as PtMn, PtCo, FePd, PdCu, PtRu, PtAu [23][24][25][26] and thin films such as (Fe 1-…”

Easy oxidative addition of the carbon–halogen bond by dimethylplatinum(II) complexes containing a related series of diimine ligands: Synthesis, spectral characterization and crystal structure

“…Description f the crystal structure of trans-[PtMe 2 EtI(4,4 0 -Me 2 bpy)] (6) The structure of complex trans-[PtMe 2 EtI(4,4 0 -Me 2 bpy)] (6) was determined by X-ray crystallography and is shown in Fig. 7.…”

“…There has been a great interest to study the oxidative addition of organoplatinum(II) complexes [1][2][3][4][5][6]. Oxidative addition of a variety of polar and nonpolar reagents including alkyl halide, aryl halide, peroxide, Sn-X, aryl-S and Bi-X to organoplatinum(II) compounds have been reported [7][8][9][10][11][12].…”