76584-41-3Relevant academic research and scientific papers
Bismuth-halide oxidative addition and bismuth-carbon reductive elimination in platinum complexes containing chelating diphosphine ligands
Nabavizadeh, S. Masoud,Niroomand Hosseini, Fatemeh,Nejabat, Negar,Parsa, Zahra
, p. 13480 - 13489 (2014/01/06)
Reaction of BiX3 (X = Cl, Br, I) with [PtMe2(P-P)], (1a, P-P = dppm; 1b, P-P = dppe), occurs easily to yield a mixture of platinum(II) complexes [PtMeX(P-P)], 2, and [PtX2(P-P)], 3, and the binuclear complex [Pt2Me2(μ-X)(μ-dppm) 2]X, 4. On the basis of 31P NMR and UV-vis spectroscopy, a mechanism is proposed in which the rate determining step is conversion of the yellowish Pt(II)-BiX3 adduct BiI3·[PtMe 2(dppm)], A, into the Pt(IV)-Bi(III) intermediate [PtMe 2(BiX2)X(P-P)], IM1. Density functional theory (DFT) studies suggest that intermediate IM1 may be formed in acetone solution which undergoes the Bi-C reductive elimination process before formation of complexes 2 and 3. The structures of intermediates IM1 were theoretically determined using DFT calculations. In dilute acetone solution, as monitored by UV-vis spectroscopy, the oxidative addition processes follow first order kinetics. The overall reaction is slower for heavier halide.
Pt-Me bond cleavage in the reactions of dimethylplatinum(II) complexes containing chelating phosphine ligands with organotin(IV) chlorides
Momeni, Badri Z.,Eatezadi, Sedigheh
, p. 1288 - 1291 (2014/01/06)
Selective Pt-Me bond activation of dimethylplatinum(II) complexes [PtMe2(PP)] (PP = dppm (bis(diphenylphosphino)methane), dppe (1,2-bis(diphenylphosphino)ethane), dppp (1,3-bis(diphenylphosphino)propane)) was achieved by SnMe2Cl2 to yield the corresponding platinum(II) complexes [PtMeCl(PP)] (PP = dppm, dppe, dppp) and cis-[PtCl 2(PP)] (PP = dppm, dppp). On the other hand, the reactions of complexes [PtMe2(PP)] (PP = dppm, dppe, dppp) with SnPh3Cl resulted in the selective cleavage of the Pt-Me bond to afford the methylplatinum(II) complexes [PtMeCl(PP)]. Notably, the reaction of [PtMe 2(dppm)] with SnMe2Cl2 and SnPh3Cl also gave the ionic A-frame complex [Pt2Me2(μ-Cl)(μ- dppm)2]Cl. The variable-temperature 1H and 31P NMR spectroscopy shows that the cleavage of the Pt-Me bond occurs very rapidly and the short-lived platinum(IV) intermediate is difficult to detect during the reaction. An explanation is presented on the basis of the nature of the strong π-acceptance of the phosphine ligand, which resulted in the formation of a very unstable platinum(IV) intermediate.
Mechanistic insight into the protonolysis of the Pt-C bond as a model for C-H bond activation by platinum(II) complexes
Romeo, Raffaello,D'Amico, Giuseppina
, p. 3435 - 3446 (2008/10/09)
The kinetic and NMR features of the protonolysis reactions on platinum(II) alkyl complexes of the types cis-[PtMe2L2], [PtMe 2(L-L)], cis-[PtMeClL2], and [PtMeCl(L-L)] (L = PEt 3, P(Pri)3, PCy3, P(4-MePh) 3, L-L = dppm, dppe, dppp, dppb) in methanol suggest a rate-determining proton attack at the Pt - C bond. In contrast, a multistep oxidative-addition - reductive-elimination mechanism characterizes the methane loss on protonation of the corresponding trans-[PtMeClL2] species. Tools that were particularly diagnostic in suggesting different reaction pathways for the two systems were (i) the different results of kinetic deuterium isotope experiments, (ii) the detection or absence of Pt(IV) hydrido alkyl intermediate species by low-temperature 1H NMR experiments, and (iii) the detection or absence of isotope scrambling and incorporation of deuterium into Pt - CH3, combined with the loss of a range of CH nDn-4 isotopomers. For all systems, the rates of protonolysis are retarded by ligand steric congestion, accelerated by ligand electron donation, and almost unaffected by the chain length along the series of chelate complexes. A straight line correlates the rates of protonolysis of cis-dialkyl and cis-monoalkyl complexes, the difference in reactivity between the two systems being almost 5 orders of magnitude (slope of the line = 6 × 104). Factors controlling the dichotomy of behavior between complexes of different geometry have been taken into consideration. Application of the principle of microscopic reversibility suggests the reason why platinum complexes with nitrogen donor ligands appear to be far more efficient than platinum phosphane complexes in activating the C-H bond.
THE SYNTHESIS OF CATIONIC A-FRAME ORGANOPLATINUM(II) DIMERS
Anderson, G.K.,Clark, H.C.,Davies, J.A.
, p. 135 - 138 (2007/10/02)
The complex (cod=1,5-cyclooctadiene) reacts with Ph2PCH2PPh2 (dppm) to yield the cationic A-frame organoplatinum(II) dimer, Cl.The phenyl and methyl analogues yield both mononuclear and the corresponding dimeric products.Previous work on the methylplatinum complex is not substantiated by these results.
