- Synthesis of mono- and polynuclear perhalophenyl palladium-platinum acetylide complexes. Molecular structure of (NBu4)2CPh)4>*4CH2Cl2
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The reaction between CR)>n (R = tBu, Ph) and the appropriate mononuclear palladium or platinum substrate affords mononuclear derivatives of the type CR)L2> (M = Pd, Pt; R = tBu, Ph; L = PPh3, dppe).Polynuclear (NBu4)2CPh)4> (X = F, Cl; R = Ph, tBu) complexes are obtained by reaction between (NBu4)2 (X' = Cl, X = F; X' = I, X = Cl) and CR)>n (Pt:Ag ratio 1:2).Similar heterometallic derivatives Q2CR)4> (Q = PMePh3, NBu4; M = Ag, Cu; R = Ph, tBu) can be prepared by reaction of Q2CR)2> with AgCl or CuCl (Pt:M ratio 1:1).The structure of (NBu4)2CPh)4>*4CH2Cl2 has been determined by X-ray diffraction.
- Espinet, Pablo,Fornies, Juan,Martinez, Francisco,Sotes, Milagros,Lalinde, Elena,et al.
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- Oxidative addition reactions of nicotinamide based organoselenium compounds on [M(PPh3)4] (M = Pd or Pt): An insight study for the formation of several isolable products
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Oxidative addition reactions of [2-NC5H3(3-COR)Se] 2 (R = NH2, NHPh, or NHpym (pym = pyrimidine)) with [M(PPh3)4] (M = Pd, Pt) in benzene afforded complexes of the type, [M{η2-SeC5H3(3-COR)N}{SeC 5H3(3-COR)N}(PPh3)] (1) (M = Pt, Pd; R = NH2, NHPh, or NHpym). A similar reaction with [2-NC5H 3(3-COOH)Se]2 gave an insoluble product which after extraction with dichloromethane gave [M(Cl){SeC5H3(3-COOH) N}(PPh3)2] (2). Compound 2, in methanolic solution is transformed into a dimeric ionic complex, but on prolonged standing in CH 2Cl2 or CHCl3 is converted into [M(Cl){η2-SeC5H3(3-COOH)N}(PPh 3)]. Treatment of [M(PPh3)4] with [2-NC 5H3(3-CONHPh)SeI] initially yielded the expected oxidative addition product [M(I){SeC5H3(3-CONHPh)N}(PPh 3)2] (4) which loses a molecule of PPh3 to give [M(I){η2-SeC5H3(3-CONHPh)N}(PPh 3)] (5). Both 4 and 5 on prolonged standing in dichloromethane gave several products such as [M(I)(Ph)(PPh3)2] (6), [2-NC 5H3(3-CO)SeNH] (9). All the complexes were characterized by elemental analyses and NMR spectroscopy. The molecular structures of [Pt{η2-SeC5H3(3-CONH2)N} {SeC5H3(3-CONH2)N}(PPh3)] (1a), [Pd{η2-SeC5H3(3-CONHPh)N}{SeC 5H3(3-CONHPh)N}(PPh3)] (1d), [Pt(I)(Ph)(PPh3)2] (6) and [Pt(Cl0.5I 0.5){C5H3(3-CONHPh)N}(PPh3) 2]·HCl (7) were established by single crystal X-ray diffraction analyses.
- Chauhan, Rohit Singh,Prabhu, C. Parashiva,Phadnis, Prasad P.,Kedarnath,Golen, James A.,Rheingold, Arnold L.,Jain, Vimal K.
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p. 163 - 170
(2013/03/13)
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- σ-bond metathesis between M-X and RC(O)X′ (M = Pt, Pd; X, X′ = Cl, Br, I): Facile determination of the relative Δ G values of the oxidative additions of RC(O)X to an M(0) complex, evidence by density functional theory calculations, and synthetic applications
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The novel utility of the ligand exchange reaction between M-X and RC(O)X′ (X, X′ = halogen; R = aryl, alkyl) is described. The relative ΔGs (ΔΔGs) of the oxidative additions of acid halides RC(O)X to M(PPh3)2Ln (M = Pt, Pd) were determined using the halogen-exchange reactions between X of trans-M(X)[C(O)R](PPh3)2 and X′ of RC(O)X′. Experimental thermodynamics data are reasonably consistent with those obtained by density functional theory (DFT) calculations. Activation parameters obtained by experiments as well as a systematic DFT study supported the fact that reactions occurred through slightly distorted quadrangular pentacoordinated σ-bond metatheses, in which the Cl atom underwent a more indirect course than the Br atom. Moreover, exchange reactions were employed as the accessible prototype for the conversion of halogen ligands of nickel triad complexes into heavier halogen ligands.
- Kuniyasu, Hitoshi,Sanagawa, Atsushi,Nakane, Daisuke,Iwasaki, Takanori,Kambe, Nobuaki,Bobuatong, Karan,Lu, Yunpeng,Ehara, Masahiro
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supporting information
p. 2026 - 2032
(2013/05/09)
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- Coulombic inter-ligand repulsion effects on the Pt(ii) coordination chemistry of oligocationic, ammonium-functionalized triarylphosphines
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The Pt(ii) coordination chemistry of oligocationic ammoniomethyl- and neutral aminomethyl-substituted triarylphosphines (L) is described. Complexes of the type PtX2(L)2 (X = Cl, I) have been isolated and characterized. For the hexa-meta-ammoniomethyl-substituted ligands [1] 6+ and [2]6+, two ligands always occupy a trans-configuration with respect to each other in complexes of the type PtX 2(L)2, while for the tri-para-ammoniomethyl-substituted ligand [7]3+, the trans/cis ratio is dependent on the ionic strength of the solution. This behaviour was not observed for the neutral aminomethyl-substituted ligands. In the crystal structure of trans-[PtI 2(1)2]I12, the geometrical parameters of the phosphine ligand [1]6+ are very similar to those found in the analogous complex of the benchmark ligand PPh3, i.e. trans-PtI 2(PPh3)2, indicating that no significant increase in the steric congestion is present in the complex. Instead, the coordination chemistry of this class of phosphine ligands is dominated by repulsive Coulombic inter-ligand interactions.
- Snelders, Dennis J. M.,Siegler, Maxime A.,Von Chrzanowski, Lars S.,Spek, Anthony L.,Van Koten, Gerard,Gebbink, Robertus J. M. Klein
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p. 2588 - 2600
(2011/05/04)
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- Cooperation between cis and trans influences in cis-Pt II(PPh3)2 complexes: Structural, spectroscopic, and computational studies
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The relevance of cis and trans influences of some anionic ligands X and Y in cis-[PtX2(PPh3)2] and cis-[PtXY(PPh 3)2] complexes have been studied by the X-ray crystal structures of several derivatives (X2 = (AcO)2 (3), (NO3)2 (5), Br2 (7), I2 (11); and XY = Cl(AcO) (2), Cl(NO3) (4), and Cl(NO2) (13)), density functional theory (DFT) calculations, and one bond Pt-P coupling constants, JPtp. The latter have allowed an evaluation of the relative magnitude of both influences. It is concluded that such influences act in a cooperative way and that the cis influence is not irrelevant when rationalizing the 1 JPtp values, as well as the experimental Pt-P bond distances. On the contrary, in the optimized geometries, evaluated through B3LYP/def2-SVP calculations, the cis influence was not observed, except for compounds CIPh (21), Ph2 (22), and, to a lesser extent, Cl(NO2) (13) and (NO2) 2(14). A natural bond order analysis on the optimized structures, however, has shown how the cis influence can be related to the s-character of the Pt hybrid orbital involved in the Pt-P bonds and the net atomic charge on Pt. We have also found that in the X-ray structures of cis-[PtX 2(PPh3)2] complexes the two Pt-X and the two Pt-P bond lengths are different each other and are related to the conformation of the phosphine groups, rather than to the crystal packing, since this feature is observed also in the optimized geometries.
- Rigamonti, Luca,Forni, Alessandra,Manassero, Mario,Manassero, Carlo,Pasini, Alessandro
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p. 123 - 135
(2010/03/04)
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- Activation of metal-bound η5-C5Me5 groups to Diels-Alder addition of 3O2 and other dienophiles
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Pt(η5-C5Me5)(PR3)I (PR 3 = PPh3, PPhCy2, PPhMetBu) reacts with 3O2 to form the metal-bound endoperoxide Pt(η1,η2-C5/s
- Boag, Neil M.,Rao, K. Mohan
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p. 1499 - 1501
(2009/09/05)
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- Cis Influence in trans-Pt(PPh3)2 complexes
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The cis influence of a series of anionic ligands X and Y has been evaluated through the magnitude of the Pt-P coupling constants for compounds of formula trans-[PtXY(PPh3)2]. The order of decreasing cis influence was found to be I > Cl > SePh ~ SPh ~ SEt > NO3 > AcO ~ NO2 > H > Me > Ph > mtc (mtc = N,N-dimethylmonothiocarbamato-S); moreover, the cis influences of the various ligands was found to be additive. The X-ray structures of three representative compounds (t-4: X = Cl, Y = NO3; t-5: X = Cl, Y = AcO and t-12: X = Y = NO2) have also been determined. The Royal Society of Chemistry 2009.
- Rigamonti, Luca,Manassero, Carlo,Rusconi, Michele,Manassero, Mario,Pasini, Alessandro
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p. 1206 - 1213
(2009/06/17)
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- Group 8 and 10 hyponitrite and dinitrosyl complexes
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cis-Hyponitrite complexes LnM(N2O2) (M = Ni, Pt; Ln = PPh3, PPh2Me, dppe, and dppf) of divalent group 10 metals have been previously shown to be readily prepared by treating the corresponding LnMCl2 derivatives with sodium-(Z)-1-{4-(2,6-di-tert-butyl-4-methoxycyclohexadienonyl)}diazen-1-ium-1,2-diolate. These complexes adopt a diamagnetic square planar geometry with oxygen bound chelating planar cis-hyponitrite ligands. They are readily prepared at room temperature but thermally decompose above 90 °C with release of nitrous oxide. Electrophiles such as iodine, methyltriflate, and hydrochloric acid also react rapidly with the cis-hyponitrite complexes to give nitrous oxide. The structure of one of these previously prepared complexes, (PPh3)2Pt(N2O2), has been redetermined at -100 °C as a dichloromethane solvate with improved precision. The related tetrahedral group 8 dinitrosyl complexes, (PPh3)2M(NO)2 (M = Ru, Os; Ln = PPh3, dppe, and dppf) have been reexamined and new derivatives with chelating phosphines have been prepared by ligand substitution on the corresponding (PPh3)2M(NO)2. The structures of Ru(dppf)(NO)2 and Os(dppe)(NO)2 have been determined. These two analogous families of cis-hyponitrite and dinitrosyl complexes illustrate the balance of metal dn electron count and nitrosyl redox state with one having linear nitrosyls bound to low valent metal centers, and the former having coupled N2 O22 - ligands bound to a higher oxidation state metal center.
- Arulsamy, Navamoney,Bohle, D. Scott,Imonigie, Jerome A.,Moore, Raecca C.
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p. 4737 - 4745
(2008/10/09)
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- Synthesis and characterization of benzylselenolate complexes of palladium(II) and platinum(II)
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Reactions of sodium benzylselenolate with several palladium(II) and platinum(II) complexes were carried out and a variety of products isolated and characterized. Reactions of Na2PdCl4 or K2PtCl4 with NaSeBz gave [M(SeBz)2]n (M=Pd or Pt; Bz=CH2Ph) which when treated with tertiary phosphines yielded [M(SeBz)2(L-L)]. The latter can also be prepared by the reaction of MCl2(L-L) (L-L=dppm, dppe or 2PPh3) with NaSeBz. Treatment of [M2X2(μ-Cl)2(PR3)2] with NaSeBz in 1:2 molar ratio afforded complexes of the type [M2X2(μ-SeBz)2(PR3)2] (M=Pd or Pt; X=Cl or Me; PR3=PEt3, PPrn3, PBun3, PMe2Ph, PMePh2 or PPh3) which existed predominantly as a cis isomer. Reaction of [M2Cl2(μ-Cl)2(PR3)2] with [M2Cl2(μ-SeBz)2(PR3)2] gave heterobridged complexes [M2Cl2(μ-Cl)(μ-SeBz)(PR3)2], the bridging chloride in the latter can be substituted with SBut or pz. All the complexes were characterized by elemental analysis and NMR (1H, 31P, 77Se, 195Pt) spectral data. Stereochemistry of these complexes has been discussed on the basis of NMR data. The crystal structure of [Pt2Cl2(μ-SeBz)2(PPrn3)2] has established a cis configuration with a bent four-membered Pt2Se2 ring. The complex [Pd(SeBz)2]n on thermolysis at 630°C yields Pd17Se15.
- Dey, Sandip,Jain, Vimal K.,Varghese, Babu
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- Synthesis and electrospray mass spectrometry of platinum(II) complexes of 5,5-diethylbarbituric acid (Hdebarb); crystal structure of cis-[PtCl(debarb)(PPh3)2]·CH2Cl 2
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The reactions of 5,5-diethylbarbituric acid (Hdebarb; 1H,3H,5H-5,5-diethylpyrimidine-2,4,6-trione), either as the monosodium salt or free acid in the presence of ancillary base (silver oxide or triethylamine), with platinum(II) halide complexes yielded mono(barbiturato) complexes cis-[PtX(debarb)L2] [X = Cl, Br or I; L = PPh3; L2 = 1,2-bis(diphenylphosphino)ethane (dppe) or 1,1′-bis(diphenylphosphino)ferrocene (dppf)]. A single-crystal structure determination of cis-[PtCl(debarb)(PPh3)2]·CH2Cl 2 showed that the plane of the N-bonded barbiturate ligand is approximately perpendicular to the platinum co-ordination square plane, rendering the two ethyl substituents inequivalent. Electrospray mass spectrometry has also been used to study these complexes, with the major ions for cis-[PtX(debarb)L2] being [Pt(debarb)L2]+ and [Pt(debarb)(NCMe)L2]+, though molecular ions [M + H]+ are also observed for all complexes. A number of cationic derivatives of the type [Pt(debarb)L2L′]+ (L = PPh3 or L2 = dppe; L′ = pyridine or PPh3) are also reported.
- Fawcett, John,Henderson, William,Kemmitt, Raymond D. W.,Russell, David R.,Upreti, Amrapali
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p. 1897 - 1903
(2007/10/03)
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- PREPARATION AND REACTIONS OF trans- (R = Me, Ph or C6H4Me-p)
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Formation of trans- (R=Me, Ph or C6H4Me-p) has been achieved by the oxidative addition of ClCH2SR to (PPh3)4Pt in refluxing PhH.The reaction of ClCH2SMe with (PMe2Ph)4Pt led to cis-.The reaction of trans-(PPh3)2Pt(CH2S
- McPherson, Helen,Wardell, James L.
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p. 261 - 266
(2007/10/02)
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- Chemical and 31P NMR spectroscopic investigations of (Ph3P)3(CO)Pt2(μ-S), a molecule with a robust Pt2S core. Applications of selective population transfer to isotopomer identification
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The 31P{1H} NMR spectra of (Ph3P)3(OC)Pt2(μ-S) and five derivatives have been analyzed. The utility of selective population transfer experiments in identifying resonances in the spectrum due to a single isotopomer and, consequently, in facilitating spectral analysis has been demonstrated. Substitution reactions of (Ph3P)3(OC)Pt2(μ-S) yield (Ph3P)2(Ph2PCH2PPh 2)Pt2(μ-S) and (Ph3P)2(CH3NC)2Pt 2(μ-S). The Pt-Pt bonds of these compounds are inert to insertion reactions by carbon monoxide, methyl isocyanide, and acetylenes. Methyl iodide alkylates these complexes to produce (Ph3P)3(OC)Pt2(μ-SCH3) + and (Ph3P)2(Ph2PCH2PPh 2)Pt2(μ-SCH3)+. (Ph3P)3(OC)Pt2(μ-S) reacts with carbon disulfide to form (Ph3P)2PtS2CS.
- Hunt, Catherine T.,Matson, Gerald B.,Balch, Alan L.
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p. 2270 - 2276
(2008/10/08)
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