42764-88-5Relevant academic research and scientific papers
SYNTHESIS AND CHARACTERIZATION OF SOME trans-HYDRIDOMETHYLBIS(PHOSPHINE)-PLATINUM(II) AND -PALLADIUM(II) COMPLEXES
Abis, Luigi,Santi, Roberto,Halpern, Jack
, p. 263 - 267 (1981)
Several trans-hydridomethylbis(phosphine)-platinum(II) and -palladium(II) complexes have been made by the reaction: trans-M(H)Cl(PR3)2 + CH3MgBr -> trans-M(CH3)(PR3)2 + MgClBr and their structures determined by 1H NMR and IR spectroscopy.The complexes in
Contrasting reactivity of fluoropyridines at palladium and platinum: C-F oxidative addition at palladium, P-C and C-F activation at platinum
Jasim, Naseralla A.,Perutz, Robin N.,Whitwood, Adrian C.,Braun, Thomas,Izundu, Joseph,Neumann, Beate,Rothfeld, Sascha,Stammler, Hans-Georg
, p. 6140 - 6149 (2008/10/09)
The divergent behavior of palladium(0) and platinum(0) is revealed in the reactivity of [M(PR3)2] (M = Pd or Pt; R = Cy or iPr) toward pentafluoropyridine and 2,3,5,6-tetrafluoropyridine. The palladium complexes react with pentafluoropyridine at 100 °C to yield the fluoride complexes trans-[Pd(F)(4-C5NF4)(PR 3)2]. They do not react with 2,3,5,6-tetrafluorapyridine. The reaction of platinum(0) complexes [Pt(PR3)2] with pentafluoropyridine in THF at ambient temperature yields trans-[Pt(R)4-C 5NF4)(PR3)(PFR2)] complexes, whereas the reaction of [Pt(PCy3)2] with 2,3,5,6- tetrafluoropyridine results in C-H activation to form cis-[Pt(H)(4-C 5NF4)(PCy3)2]; this complex may be converted to the trans isomer by photolysis. The cis-hydride also forms during the reaction of [Pt(PCy3)2] with C5NF 5 in hexane. These reactions also contrast with earlier studies of the reactivity of the same substrates toward {Ni(PEt3)2}, which yield [Ni(F)(2-C5NF5)(PEt3)2] with pentafluoropyridine and [Ni(F)-(2-C5NF4H)(PEt 3)2] with tetrafluoropyridine. Thus palladium has different regioselectivity from nickel and is the least reactive. Platinum is capable of both C-F and C-H activation and is alone in the triad in undergoing rearrangement to the alkyl complex with the fluorophosphine ligand. Mechanisms for the rearrangement are proposed. The platinum dihydride complex trans-[Pt(H)2(PR3)2] reacts with pentafluoropyridine at room temperature, yielding a 1:1:1 mixture of trans-[PtH(FHF)(PR3)2], trans-[Pt(H)(4-C 5NF4)(PR3)2], and trans-[Pt(R)(4-C5NF4)(PR3)(PFR2)]. Crystal structures are reported for trans-[Pd(F)(4-C5NF 4)-(PCy3)2]-H2O-C6H 6, trans-[Pd(F)(4-C5NF4)(PiPr 3)2], trans-[Pt(C6H11)(4-C 5NF4)(PCy3)(PFCy2)]-CH 2Cl2, and cis-[Pt(H)(4-C5NF4) (PCy3)2].
Investigations of the Factors Affecting the Stability of Dihydrogen Adducts of Platinum(II)
Stahl, Shannon S.,Labinger, Jay A.,Bercaw, John E.
, p. 2422 - 2431 (2008/10/08)
The preparation and study of Pt(II) H2 adducts and Pt(IV) dihydride complexes are described. The species of interest are generated by protonation of hydridoplatinum(II) complexes of the type trans-(PCy3)2Pt(H)X [X = SiHsu
Reaction of trans-[Pt(H)2(PCy3)2] with C60 Reductive elimination of H2 and formation of [Pt(PCy3)2(η2-C60)]
Pandolfo, Luciano,Maggini, Michele
, p. 61 - 65 (2007/10/03)
Reaction of trans-[Pt(H)2(PCy3)2], 1, with [60]fullerene at room temperature affords [Pt(PCy3)2(η2-C60)], 2, in nearly quantitative yield. The most probable reaction pattern is the insertion of a fullerene 6,6 junction onto a Pt-H bond yielding an η1 alkyl derivative which, after hydrogen extrusion, gives 2. On the other hand, addition of 1 to different electron-deficient olefins, such as dimethyl maleate and fumarate, furnishes mixtures of both η1 metal-alkyl and η2 metal-olefin derivatives. If tetrachloroethylene is used as 27π component, trans-[PtCl(H)(PCy3)2] forms exclusively.
Cyclohexyneplatinum(0) Complexes Containing Di-t-butylphenylphosphine, t-Butyldiphenylphosphine or Trimethylphosphine
Bennett, Martin A.,Fick, Hans-Georg,Warnock, Garry F.
, p. 135 - 142 (2007/10/02)
Cyclohexyneplatinum(0) complexes Pt(C6H8)L2 (L = PBut2Ph (4), PButPh2 (5)> analogous to the known complex (3) (L = PPh3) have been prepared by reaction of the two-coordinate complexes PtL2 with 1,2-dibromocyclohexene and 1percent sodium amalgam.The corresponding tricyclohexylphosphine complex is formed by a similar reaction but it could not be isolated in a pure state.Attempts to prepare analogues of (4) and (5) containing cycloheptyne or cyclooctyne were unsuccessful, possibly because the bulky t-butyl groups of the tertiary phosphines hinder coordination of the largerrings.Bulky tertiary phosphines do not displace PPh3 from (3) but trimethylphosphine reacts with (3) to give successively Pt(C6H8)(PMe3)(PPh3) (10) and Pt(C6H8)(PMe3)2 (11), as shown by 31P n.m.r spectroscopy.The tertiary phosphines in these complexes equilibrate rapidly at room temperature in benzene and only (10) can be isolated as a solid from the reaction.Complexes (4) and (5) react with HCl (1 molar proportion) to give η1-cyclohexen-1-yl complexes trans-PtCl(C6H9)L2 t2Ph (6), PButPh2 (7)>.In the absence of air, (4) reacts with methanol at 65 deg C to give the hydrido complex trans-PtH(C6H9)(PBut2Ph)2 (8).In the presence of oxygen from the air, however, the main product is the dioxygen complex Pt(O2)(PBut2Ph)2 (9).This represents an unusual example of complete displacement of cyclohexyne from a platinum(0) complex by a ?-acceptor ligand.
Synthesis and reaction chemistry of monomeric and dimeric amide complexes of platinum(II)
Park, Soonheum,Rheingold, Arnold L.,Roundhill, D. Max
, p. 615 - 623 (2008/10/08)
A series of complexes trans-[PtH(NH3)L2]ClO4 (L = PPh3, PEt3, PCy3), trans-[PtMe(NH3)L2]ClO4 (L = PPh3, PEt3, PMePh2, PCy3), and [PtMe(NH3)dppe]ClO4 have been synthesized from trans-PtH(ClO4)L2, trans-PtMe(ClO4)L2, and PtMe(ClO4)dppe and ammonia, respectively. Reacting trans-[PtH(NH3)L2]ClO4 (L = PPh3, PEt3) with NaNH2 gives [PtH(μ-NH2)L]2 as a mixture of anti and syn isomers. The complexes reductively eliminate ammonia. Reacting trans-[PtMe(NH3)L2]ClO4 (L = PPh3, PEt3, PMePh2) with NaNH2 gives the stable complexes [PtMe(μ-NH2)L]2 as mixtures of anti and syn isomers. For L = PPh3, PMePh2, PEt3, the percentage anti isomer is 100, 75, and 50, respectively. For L = PEt3, the intermediate complex trans-PtMe(NH2)(PEt3)2 has been observed. Reacting [PtMe(μ-NH2)L]2 with L (L = PPh3, PEt3) gives cis-PtMe(NH2)L2. Reacting trans-[PtH(NH3)(PCy3)2]ClO4, trans-[PtMe(NH3)(PCy3)2]ClO4, or trans-[PtPh(NH3)(PCy3)2]ClO4 with NaNH2 gives trans-PtH(NH2)(PCy3)2, trans-PtMe(NH2)(PCy3)2, or trans-PtPh(NH2)(PCy3)2. Reacting [PtMe(μ-Cl)PCy3]2 with AgClO4 then NH3 gives [PtMe(NH3)2PCy3]ClO4. Treating [PtMe(NH3)2PCy3] with NaNH2 gives an equimolar mixture of anti and syn isomers of [PtMe(μ-NH2)PCy3]2. The syn isomer, which has been isolated, converts to a mixture of syn and anti in the presence of tricyclohexylphosphine in CDCl3 solution. The compound anti-[PtMe(μ-NH2)PPh3]2 crystallizes in the space group C2/c with a = 22.592 (5) A?, b = 11.844 (3) A?, c = 29.403 (6) A?, β = 116.43 (2)°, and Z = 8. The two crystallographically independent molecules with Pt(1)-Pt(1A) and Pt(2)-Pt(2A) distances of 3.106 (1) and 3.117 (1) A?, respectively, are associated by Pt?H interactions. The complex trans-PtMe(NH2)(PCy3)2 reacts with CF3SO3H to give trans-[PtMe(NH3)(PCy3)2]CF3SO 3. The complex trans-PtPh(NH2)(PCy3)2 reacts with CF3SO3H and H2O to give trans-[PtPh(NH3)(PCy3)2]CF3SO 3 and trans-[PtPh(NH3)(PCy3)2]OH, respectively. trans-PtPh(NH2)(PCy3)2 reacts with methyl iodide and allyl chloride to give trans-PtPhI(PCy3)2 and trans-PtPhCl(PCy3)2, respectively. Carbon dioxide reacts with trans-PtPh(NH2)(PCy3)2 to give trans-PtPh(NHCO2H)(PCy3)2 then trans-PtPh(OCONH2)(PCy3)2.
Stability of (Chloromethyl)platinum(II) Complexes
McCrindle, Robert,Arsenault, Gilles J.,Gupta, Anuradha,Hampden-Smith, Mark J.,Rice, Richard E.,McAlees, Alan J.
, p. 949 - 954 (2007/10/02)
The stabilities of , (cod = cycloocta-1,5-diene) and a range of phosphine-containing mono- and cis-bis-(chloromethyl)platinum(II) complexes have been investigated in deuteriochloroform at room temperature.Some of the bis(chloromethyl) derivatives appear to be indefinitely stable (cod and chelating arylphosphines), others suffer very slow decomposition to the dichlorides (non-chelating arylphosphines), and the remainder decompose relatively rapidly, and cleanly, to the dichlorides plus ethylene (alkylphosphines, non-chelating faster than chelating).Rapid decomposition of the arylphosphine complexes can be induced by adding hexafluoroisopropyl alcohol to the deuteriochloroform solutions.Attempts to generate 2> by addition of P(C6H11)3 to resulted in the formation of cis--+(C6H11)3>Cl2>; a mechanism is proposed.All cis-mono(chloromethyl) derivatives studied appear to be indefinitely stable.In contrast, the trans-mono(chloromethyl) complexes, although stable in very dry solvent, undergo decomposition in the presence of moisture to the corresponding hydrides plus formaldehyde; a mechanism is proposed.The hydrides undergo subsequent conversion into a mixture of cis and trans dichlorides.
Synthesis of Hydridotrifluoromethyl Complexes of Platinum(II). A Spectroscopic Investigation of the trans and cis Influence of Ligands in Hydridoplatinum(II) Compounds
Michelin, Rino A.,Ross, Renzo
, p. 1149 - 1160 (2007/10/02)
The starting complex trans- is prepared from trans- by treatment of the derived labile solvento cationic species trans-BF4 (solv = acetone or CH2Cl2) with NaBH4 in EtOH at 0 dec C.The hydridotriflouromethyl complexes trans- are obtained by reaction of trans-PtH(CF3)(PPh3)2> with 2 equivalents of phosphine, L, in n-heptane at room temperature.Similar exchange reactions between trans- and equivalent amounts of diphosphine, L-L = cis-Ph2PCH=CHPPh2, Ph2PCH2CH2PPh2, Me2PCH2CH2PMe2, or Ph2PCH2CH2CH2PPh2, lead to the formation of the corresponding compounds.The hydridotrifluoromethyl complexes with L-L = cis-Ph2PCH=CHPPh2 and Ph2PCH2CH2PPh2 can be prepared also by reaction of the parent chloro derivatives with NaBH4 in EtOH at room temperature.The mixed isocyanide-phosphine complexes are obtained by reaction of trans- with a three-fold excess of RNC in n-heptane at room temperature.All the hydridotrilfluoromethyl complexes are air-stable in the solid state and in solution.They were characterized by elemental analyses and i.r., (1)H, (19)F, and (31)P n.m.r. spectra.The data obtained for υ(PtH) and (1)J(PtH) in trans- have been used to compare the trans influence of CF3(1-) with other ? carbon donors, R, in trans- derivatives.The n.m.r.-based trans influence order is CF3(1-) > C6H5(1-) > C6H9(1-) > CH2CH2CN(1-) > CH2CH2CH2CN(1-) > CH3(1-) > CH2CN(1-) > Cl(1-), whereas the i.r.-based trans influence order is C6H9(1-) > CH2CH2CH2CN(1-) > C6H5(1-) = CH3(1-) > CF3(1-) > Cl(1-).The opposite position of CF3(1-) in the two series of trans influence has been explained by the different mechanism operating on (1)J(PtH) and υ(PtH).The first depends predominantly on the s character of the platinum hydrid orbital used in the Pt-H bond, while the second is sensitive also to electrostatic effects induced by the electronegative fluorine atoms.The (1)J(PtP) data for the same series of complexes gives the following order of cis influence: Cl(1-) > CH2CN(1-) > CF3(1-) = CH3(1-) = C6H5(1-) = CH2CH2CN(1-) > CH2CH2CH2CN(1-).From the spectra of trans- (X = CF3 or Cl), the effects of replacing two PPh3 ligands in trans- by L on υ(PtH) and (1)J(PtH) were measured.With the assumption that the cis effects are additive, the i.r. and n.m.r. parameters were correlated with the electronic χ and steric θ parameters of the phosphine ligands.
CHEMISTRY OF METAL-DIENE COMPLEXES; A DIRECT, NEW PREPARATIVE ROUTE TO HYDRIDO-PLATINIUM(II) COMPLEXES
Clark, Howard C.,Goel, Anil B.,Goel, Sarla
, p. C25 - C28 (2007/10/02)
A new preparative route to hydrido-platinum(II) complexes, particularly those containing bulky phosphines which are inaccessible by other methods, involves the convenient reaction of phosphines with bis in methanol.A β-hydrogen elimination mechanism is described, as well as the preparation and use as hydrogenation catalysts of the complexes trans- where L=tertiary phosphine.
