17567-35-0Relevant academic research and scientific papers
THE SYNTHESIS, CHARACTERIZATION AND REACTIONS OF A BINUCLEAR TETRAMETHYLPLATINUM(IV) COMPLEX
Lashanizadehgan, Marym,Rashidi, Mehdi,Hux, Janet E.,Puddephatt, Richard J.,Ling, Samson S. M.
, p. 317 - 322 (1984)
Reaction of excess MeLi and MeI with gives the first binuclear tetramethylplatinum(IV) complex .The characterization of this complex, and its reactions with donor ligands to give cis- (L2 = Ph2PCH2PPh2, Ph2PCH2CH2PPh2, 2,2'-bipyridyl, 1,10-phenanthroline or L = PMe2Ph, PMePh2) are described.
Substitution reactions of NN chelating atoms of organoplatinum (II) complexes with phosphorous donor reagents
Hoseini, S. Jafar,Nasrabadi, Hasan,Masoud Nabavizadeh,Rashidi, Mehdi
, p. 22 - 27 (2013/03/29)
Substitution reactions of the chelate 2,2′-bipyridine ligand in the organoplatinum(II) complexes of general formula [PtR2(NN)] (NN = 2,2′-bipyridine, and R = CH3, 1, or R = p-CH3C 6H4, 1′) by the P donor reagents L, L = P(O- iPr)3 or PPh3 or L2 = dppm, bis(diphenylphosphino)methane, to form the complexes cis-[R2PtL 2] were studied. Each of the complexes 1 and 1′ has an MLCT band in the visible region which was used to easily follow kinetics of the related ligand substitution reactions by UV-Vis spectroscopy. Although the complex 1 or 1′ contains two cis Pt-C bonds, the involved substitution reaction followed a normal associative mechanism. The reaction rates were found to be dependent on concentration and nature of the entering group, while independent of the presence of excess free NN leaving group. Reaction of the complex 1 with P(O-iPr)3 proceeded some 20 times faster than similar reaction with the complex 1′. The ΔH ?/ΔS? compensation plot gives a straight line suggesting operation of the same mechanism involving all the entering nucleophiles.
Synthesis and reactivity of new κ2-[P,N]Pt(II) complexes of diisopropylphosphino-substituted 2-dimethylaminoindene
Wile, Bradley M.,McDonald, Robert,Ferguson, Michael J.,Stradiotto, Mark
, p. 1959 - 1965 (2008/10/09)
Treatment of 1-PiPr2-2-NMe2-indene (la[H]) with either czs/trans-(SMe2)2PtCl2 or PtCl2 provided (κ22-P,N-2-NMe2-3-P iPr2-indene)PtCl2 (2) in 84% and 55% yield, respectively, while the reaction of 1a[H] with (η4-COD)PtClMe afforded (κ2-P,N-2-NMe2-3-PiPr 2-indene)PtClMe (3) in 91% yield. Whereas in the formation of 2 and 3 the ligand precursor 1a[H] undergoes a rearrangement to give a coordinated 2-NMe2-3-PiPr2-indene (1b[H]) ligand, 1a[H] reacted cleanly with 0.5 equiv of [(μ-SMe2)PtMe2] 2 to give (κ2-P,N-1a[H])PtMe2 (4a) in 97% yield. The isomerization of 4a to (κ2-P,N-1b[H])PtMe 2 (4b) in a THF/iPrOH mixture is rapid and allowed for the isolation of 4b in 99% yield. Heating of 4a in CH2Cl2 resulted in the quantitative formation of 3, while the thermolysis of 4a in toluene in the presence of SMe2 afforded 5, the apparent product of intramolecular C-H activation of an NMe group. The reactivity of 4a with a variety of other two-electron donors, as well as E-H-containing substrates (E = main group fragment), is reported. Although NMR spectroscopic evidence indicated the formation of an intermediate of the type (κ2-P,N-1[H]) Pt(SnPh3)(Me), as well as Ph6Sn2, in the reaction of 4a with 10 equiv of Ph3SnH, negligible conversion of Ph3SnH to Ph6Sn2 was obtained when employing 1 mol % 4a as a catalyst. Single-crystal X-ray diffraction data for 2 and 5 are reported.
Binding of specialty phosphines to metals: Synthesis, structure, and solution calorimetry of the phosphirane complex [PtMe2(iPrBABAR-Phos)2]
Laporte, Cecile,Frison, Gilles,Gruetzmacher, Hansjoerg,Hillier, Anna C.,Sommer, William,Nolan, Steven P.
, p. 2202 - 2208 (2008/10/08)
The complex [PtMe2(iPrBABAR-Phos)2] (3) was prepared in a clean and quantitative ligand substitution reaction from [PtMe2(cod)] (1; cod = η4-1,5-cyclooctadiene) and the phosphirane iPrBABAR-Phos (2). The structure of 3 was determined by X-ray diffraction. The Pt-P bonds (～2.26 A) lie in the shorter range of PtII-P bonds, although the 1J(195Pt31P) coupling (1840 Hz) is quite small. The enthalpy for this ligand substitution reaction was measured by solution calorimetry and found to be exothermic by 11.8 kcal/mol, a relatively low exothermicity for a reaction involving a tertiary phosphine in this Pt system. Calculations using density functional theory (DFT) on the B3LYP level were applied using the simplified model reaction [PtH2(cod)] + 2(H2N)PC2H4 → [PtH2{(H2N)PC2H4}2)] + cod, and these also gave a rather low substitution enthalpy (-17 kcal/mol). A charge decomposition analysis (CDA) was performed for Pt(II) and Pt(0) complexes with the simple P-amino phosphirane (H2N)PC2H4 and PH3 as ligands. Contrary to expectations, it is found that the phosphirane acts as a relatively good electron donor, while its electron-acceptor properties are not significantly different from those of other phosphines. The particularly low reaction enthalpy may thus be due to a low directionality of the donor orbitals toward the metal center.
C-Pt(IV) activation in new trimethylplatinum(IV) complexes: Nucleophilic attack at metal-carbon bond
Romero, Patricio,Valderrama, Mauricio,Contreras, Raúl,Boys, Daphne
, p. 102 - 110 (2007/10/03)
Reaction of the tetranuclear complex [Me3PtI]4 with the ligand o-Ph2P(E)C6H4SMe (E=S, Se) in a 1:4 molar ratio yields the mononuclear neutral complexes [Me3PtI{η2-MeSC6 H4P(E) Ph2-S,S}] (E=S(1), Se(2)). Iodide abstraction from these compounds with AgPF6 in the presence of a ligand L (PPh3, py) leads to cationic complexes of the type [Me3Pt(η2-MeSC6H4P(E) Ph2-E,S)L]PF6 [E=S, L=PPh3 (3), Py (4); E=Se, L=Py (5)]. However, using complex 2 and the ligand PPh3 under identical conditions induces a reductive elimination reaction affording the Pt(II) complex [MePt(η2-MeSC6 H4PPh2- P,S)(PPh3)]PF6 (6). Reactions of complexes 3 and 4 with NaI reveal a nucleophilic attack of the iodide to one of the methyl groups bonded to the platinum center generating a series of subsequent side reactions. Complex [Me3Pt{η2- MeSC6H4P(S) Ph2-S,S}(py)]PF6 ·CH2 Cl2 (4) was additionally characterised by X-ray diffraction. The platinum atom exhibits a distorted octahedral coordination, bonded to three methyl carbon atoms in a facial arrangement; a bidentate chelate S,S′-bonded ligand and a nitrogen atom of the pyridine ligand complete the metal coordination sphere.
Reactions of organotin(IV) compounds with platinum complexes. Part II. Oxidative addition of SnRxCl4-x to [Pt(COD)2] and subsequent reactions with tertiary phosphines
Al-Allaf, Talal A. K.
, p. 25 - 35 (2007/10/03)
Organotin(IV) compounds SnRxCl4-x (R=Me, Ph; x=4-0) add oxidatively to [Pt(COD)2] (COD=cycloocta-1,5-diene) to yield platinum(II) complexes in which Pt has inserted into the Sn-Cl or Sn-R bonds, displacing one COD entity. The new com
Structure - Reactivity correlations for the dissociative uncatalyzed isomerization of monoalkylbis(phosphine)platinum(II) solvento complexes
Romeo, Raffaello,Alibrandi, Giuseppe
, p. 4822 - 4830 (2008/10/09)
Complexes of the type a's-[PtL2Me2] (1-14) (L = an extended series of phosphines of widely different steric and electronic properties) were synthesized, characterized, and used as precursors for the formation of cis-monoalkylplatinum(II) solvente species in methanol. The cleavage of the first platinum-alkyl bond by protonolysis is a fast process, but the subsequent cis to trans isomerization of the cationic solvento species [PtL2- (Me)(MeOH)]+ is relatively slow and it can be monitored using 31P NMR or conventional spectrophotometry. A large collection of 1H and 31P NMR data for cis-[PtL2Me2], cis-[PtL2Me(MeOH)]+, and trans-[PtL2Me(MeOH)]+ complexes showed interesting dependencies upon the size, the α-donor capacity, and the mutual position of the phosphines in the coordination sphere of the metal. The rate constants for isomerization of cis-[PtL2Me(MeOH)]+ were resolved quantitatively into steric and electronic contributions of the phosphine ligands, by means of correlations with parameters which reflect their σ-donor ability (Χ values) and steric requirements (Tolman's cone angles, θ). The electronic and steric profiles obtained for these reactions are discussed within the framework of a mechanism which involves dissociative loss of the solvent molecule and interconversion of two geometrically distinct 3-coordinate T-shaped 14-electron intermediates. The factors controlling the stability of these coordinatively unsaturated species are discussed. The electronic and steric influences of phosphines as spectator ligands in a dissociative process are compared with those shown by these ligands when used as nucleophiles in associative substitution processes. The activation parameters ΔH? and ΔS? were measured using both conventional isothermal and non-isothermal spectrophotometric kinetics.
Studies of binuclear methyl and phenyl derivatives of platinum(II)
Rashidi, Mehdi,Fakhroeian, Zahra,Puddephatt, Richard J.
, p. 261 - 267 (2007/10/02)
Some reactions of the binuclear organoplatinum complexes , where R = Me or Ph are described, and a new synthetic method for the complex with R = Ph is reported.The dimethylsulphide ligands are easily displaced by other ligands, L, to give cis-.When R = Me, reaction with MeI and Ph2PCH2PPh2, dppm, gives 2(μ-dppm)>, whereas when R = Ph, reaction with MeI gives , which has been characterized as its adduct with 2,2'-bipyridine .The latter complex exists as a mixture of two isomers, though the reaction between and MeI initially gives only one isomer of , formed by trans-oxidative addition.The reaction of with hydrochloric acid yields a 1:1 mixture of and , and it is suggested that this reaction involves an intramolecular methyl group transfer between the platinum atoms of the dimer.
