1,721,008 research outputs found
Reaction of [Pt-2(dppp)(2)(H)(3)][BF4] with styrene or phenylacetylene gives the same mu-hydrido mu-alkylidene derivative, [Pt-2(dppp)(2)(mu-H)(mu-CHCH2Ph)][BF4]
No full textThe reaction of the binuclear platinum hydride [Pt-2(dppp)(2)(H)(3)][BF4] with styrene or phenylacetylene gives the same mu-hydrido mu-alkylidene diplatinum complex, [Pt-2(dppp)(2)(mu-H)(mu-CHCH2Ph)][BF4], under the same mild experimental conditions. Experiments with deuterium-labeled reagents show that the hydrogenation of phenylacetylene does not occur through the transfer of the acetylenic proton and suggest that the hydrogenation to styrene as an intermediate step is not implied. The C-13 NMR spectra of the reaction product of an equimolecular mixture of [Pt-2(dPPP)(2)(H)(3)][BF4] and [Pt-2(dppp)(2)(D)(3)][BF4] with phenylacetylene suggest that fragmentation of the dimeric Pt2H3+ core does not occur. Possible phenylacetylene hydrogenation pathways are discussed
Protonation of platinum(II) pyrazolates: synthesis, characterization and X-ray crystal structure of [Pt(dppe)(Hpz-N)(2)][BF4](2)center dot CHCl3 center dot H2O (Hpz-N = unsubstituted pyrazole)
No full textProtonation reactions of [Pt(dppe)(pz-N)(2)] (1) carried out either with HBF4(aq) or with [18-crown-6 .H3O][BF4], afford the new pyrazole adduct [Pt(dppe)(Hpz-N)(2)][BF4](2) (3) characterized by analytical, infrared and multinuclear NMR data. Deprotonation of 3 as well as protonation of 1, under controlled conditions, give the known binuclear Pt(II) pyrazolato complex [Pt(dppe)(mu -pz-N,N'](2)[BF4](2) (2). Competitive formation of mono-, 3, and dinuclear, 2, compounds is discussed. The structure of a solvate of complex 3, (C33H35B2N4OF8Cl3P2Pt), was solved by X-ray diffraction. The platinum atom exhibits a distorted square-planar geometry (P-Pt-P angle 85.3(1)degrees and N-Pt-N angle 87.0(4)degrees). The geometry around the B atom is tetrahedral. The hydrogen bonds between the pyrazole rings and one BF4- orientate the pyrazoles roughly in the same direction, away from the coordination plane. (C) 2001 Published by Elsevier Science Ltd
Binuclear hydride platinum(II) complexes: syntheses of [{Pt(P-P)}(2)(mu-CHCH2R)(mu-H)][BF4] (R = C6H5, H) and easy cleavage of a P-C bond in a chelating 1,4-bis (diphenyl)phosphinobutane (P-P)
No full textReactions of the binuclear platinum(II) trihydrido complex. [Pt-2{(Ph2P)(2)(CH2)(4)}(2)(H)(3)][BF4], with styrene or ethylene, at room temperature and low pressure, give mu-alkylidene, mu-hydrido cationic species [Pt-2{(Ph2P)(2)(CH2)(4)}(2)(mu-CHCH2R)(mu-H)][BF4] (R = C6H5, 1; H, 2) together with an unexpected phosphido-bridged binuclear platinum(II) compound (3), originating from cleavage of a P-C bond in the coordinated diphosphine. Complexes 1-3 are discussed on the basis of FAB MS, IR and multinuclear NMR spectra in solution. (C) 2000 Elsevier Science S.A. All rights reserved
Ionic binuclear platinum(II) hydrides
No full textThe new hydrides [(LL)2Pt2H3][BF4] (I: LL = 1,2-bis(diphenylphosphino)ethane; II: LL = 1,2-bis(diphenylarsino)ethane) were obtained by reaction of (LL)Pt(PzH)2][BF4]2 (PzH = 3,5-dimethylpyrazole) with KBH4 in MeOH or EtOH. © 1977
FAST ATOM BOMBARDMENT INDUCED DECOMPOSITION PATTERN OF THE GOLD(III) BIS(CARBENE) COMPLEX [((PARA-MEC6H4NH)(ETO)C)2AUI2]CIO4, A RETROSYNTHETIC PROCESS
No full textThe fast atom bombardment (FAB) induced decomposition pattern of the ionic bis(carbene)gold(HI) complex [{(P-MeC6H4NH)(EtO)C}2AuI2]ClO 4 (1) is described and discussed in detail with the aid of metastable data. A lack of [M]+ ions is observed when sulfolane is used as the matrix. Instead, the molecular species observed is the [M - H]•+ ion. The fragmentation pattern can be considered as a retrosynthetic process of the compound itself, never previously observed for an organometallic under FAB conditions. The MS pattern suggests the synthesis of the new carbene-methanide derivative 2, [{(p-MeC6H4NH)-(EtO)C}{(p-MeC6H 4N=)(EtO)C}Au], observed under FAB-MS conditions as the most stable ion. An independent synthesis was successful
An Investigation on Various Bis (N-substituted-imino)(alkoxy)methyl platinum(II) Derivatives as Ligands Towards Group IIB Halides and Rhodium Dicarbonyl Chloride
No full textThe adducts A.ZaBr2, B.2nBr2, A.CdI2, A.CdBr2, C.CdI2, B.CdI2, C.HgCI2, C.2HgCl2, D.HgCI2, A.Rh(CO)2Cl were prepared from the corresponding halide and the ligand A, (Ph3P)(ArNC)Pt-[c(OMe)=NAr]2 B, (DFE)Pt{c(OMe)=NAr]2, C, (DPE)Pt-[c(OMe)=NMe]2or D, (DPE)Pt-|c(OMe)=NCgH112(Ar= p-tolyl, DPE= 1,2-bis(diphenylphosphino) ethane). These platinum(II) bidentate ligands are basic since they can be proton at ed at the two imino nitrogens, which are likely to be the donor sites in the adducts
AN IR-193 AND AU-197 MOSSBAUER INVESTIGATION OF IRIDIUM(I), IRIDIUM(III) AND IRIDIUM(I) GOLD(I) COMPLEXES
No full textComparison of the Ir-193 and Au-197 Mossbauer spectra of the series trans-(Ph3P)2Ir(CO)X, trans,cis-(Ph3P)2(H)2Ir(CO)(X) (X = Cl or pz-N; pzH = 3,5-dimethyl-, 3,5-dimethyl-4-nitro-, 3,5-bis(trifluoromethyl)pyrazole) and trans-(Ph3P)2(CO)Ir[mu-(3,5-dimethylpyrazolato-N,N')]AuX' (X' = Cl, Br) shows that even the substituents on the heterocycle influence the electron density at the iridium nucleus and that the bridging pyrazolato ligand transmits electronic effects from gold to iridium through three bonds. The Mossbauer parameters are sensitive to the ligand X but not to the presence of conformers
NMR-STUDY OF THE CHEMICAL-EXCHANGE OF THE HYDRIDO LIGANDS IN THE BIS(BIS(DIPHENYLPHOSPHINO)ETHANE)TRIHYDRIDODIPLATINUM(II) CATION BY T1, T2, AND HD ISOTOPIC PERTURBATION
No full textProton longitudinal and transverse relaxation rates of hydrido resonances of different isotopomers in [H3Pt2(Dpe)2][BF4] [Dpe = bis(diphenylphosphino)ethane] show significant differences in the satellite peaks with respect to the central ones that can be used to evaluate the activation energy of the intramolecular exchange process and the chemical shift separation between bridging and terminal sites. An alternative route to get an estimation of the chemical shift values of the bridging and terminal hydrides in this derivative has been pursued by considering the isotopic shift of the three H-3, H2D, and HD2 isotopomers at different temperatures
Multinuclear (1H, 31P, and 195Pt) NMR study and dynamical analysis of binuclear μ-hydrido μ-carbonyl Pt(I) cations with chelating diphosphines
Full text linkThe dynamic behaviour of the binuclear μ-hydrido μ-carbonyl cations with chelating diphosphines, [Pt2(P–P)2-(μ-H)(μ-CO)]+ [P–P = dppe, 1, dppp, 2, and dppb, 3] have been investigated by multinuclear (1H, 31P and 195Pt)variable temperature NMR spectroscopy. The 195Pt and 1H results are consistent with intramolecular mutual exchange of the P atoms with respect to the bridging ligands in all of the complexes 1–3. A detailed dynamical
analysis carried out on complexes 2 and 3 shows that the dynamical process exchanges the P atoms within a single diphosphino ligand, and excludes the simultaneous P atom exchange in both ligands. The bite of the diphosphino ligands affects the rate of this process in the order 3 > 2 > 1. The process follows an activation law with ΔH‡ = 67
and 60 kJ mol^(-1) for 2 and 3, respectively, so that P–Pt bond breaking should not be involved. The positive activation entropy (17–19 J K^(-1) mol^(-1) hints at a mechanism where the intermediate(s) have a less ordered structure than that of the stable complex. In accordance with the NMR results, two reactivity experiments provided further evidence of the intramolecular nature of the observed dynamics and exclude any equilibration path via Pt–P and/or Pt–Pt bond breaking. On these grounds, a mechanism involving rotation about a Pt–Pt bond could be proposed
Platinum(I) dinuclear hydrides
No full textThe novel complexes [(dpe)2Pt2(CO)(H)][X] and [(dpe)2Pt2(CNR)(H)][X] (X = BF′4, I;dpe = 1,2-bis(diphenylphosphino)ethane; R = p-tolyl, methyl and t-butyl) were obtained by reaction of [(dpe)2Pt2H3][X] with CO or isocyanides. © 1979
- …
