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Platinum Complexes (platinum + complex)

Distribution by Scientific Domains

Chemistry	81%
Polymers and Materials Science	8%
2 Other Domains	11%

Distribution within Chemistry

General & Introductory Chemistry	35%
Organic Chemistry	16%

Selected Abstracts

Site-Selective Ser-Hydrolase Labelling with a Luminescent Organometallic NCN,Platinum Complex

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2010
Birgit Wieczorek
Abstract The synthesis, spectroscopic properties and protein-binding studies of a novel luminescent organometallic NCN,platinum complex are described. The luminescent organometallic complex was linked to a serine hydrolase reactive phosphonate group by means of click chemistry, and was exploited in serine hydrolase specific-binding studies using gel electrophoresis. The NCN,platinum protein label was found to be a robust dye with absorbance and emission maxima between 374,380 and 482,493 nm, respectively, and quantum yields between 0.04 and 0.15. [source]

Uncommon Solvent Effect in Oxidative Addition of MeI to a New Dinuclear Platinum Complex Containing a Platina(II)cyclopentane Moiety

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 32 2008
S. Jafar Hoseini
Abstract The reaction of the known complex cis,cis -[Me2Pta(,-dppm)(,-SMe2)Ptb,CH2(CH2)2CcH2(Ptb,Cc)] [dppm = bis(diphenylphosphanyl)methane] with phthalazine (NN) proceeded by replacement of the labile bridging SMe2 ligand with the bidentate N-donor ligand NN to give cis,cis -[Me2Pta(,-dppm)(,-NN)Ptb,CH2(CH2)2CcH2(Ptb,Cc)] (1) as a pale red solid in good yield. The complex was fully characterized by multinuclear (1H, 31P, 195Pt) NMR spectroscopy. The subsequent reaction of complex 1 with excess MeI gave the colorless diplatinum(IV) complex [Me3Pta(,-dppm)(,-I)2Ptb{CH2(CH2)2CcH2(Ptb,Cc)}Me], in which the bridging NN ligand is replaced by bridging iodido ligands. The reddish color of complex 1, which is due to a metal-to-ligand charge transfer (MLCT) band in the visible region, was used to monitor its reaction with MeI in the solvents acetone, CH2Cl2, and benzene. The kinetic data revealed that the reactions in nonpolar benzene or slightly polar CH2Cl2 proceeded in two steps, each following a common SN2 mechanism. In the first step, MeI attacked the platina(II)cyclopentane center rather than the dimethylplatinum(II) center, because the first center is more electron-rich than the second center. In the more polar acetone, the reaction proceeded similarly, with the exception that each step was accompanied by a solvolytic reaction, which was suggested to be responsible for the unusually slower reaction rate in acetone than in benzene or CH2Cl2. Consistently, the reaction rate in the highly polar solvent CH3CN was too slow for any meaningful measurement.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Innentitelbild: Synthesis of [8]Cycloparaphenylene from a Square-Shaped Tetranuclear Platinum Complex (Angew. Chem.

ANGEWANDTE CHEMIE, Issue 4 2010
4/2010)
Vom Quadrat zur Schlaufe:In ihrer Zuschrift auf S.,769,ff. beschreiben S. Yamago et,al. die erste Synthese von [8]Cycloparaphenylen, das in drei Stufen und mit einer Gesamtausbeute von 25,% aus 4,4,-Bis(trimethylstannyl)biphenyl und [PtCl2(cod)] (cod=1,5-Cyclooctadien) über ein quadratisches Platin-Biphenyl-Intermediat entstand. [8]Cycloparaphenylen zeigt eine intensive gelbgrüne Fluoreszenz bei etwa 540,nm. [source]

Synthesis of [8]Cycloparaphenylene from a Square-Shaped Tetranuclear Platinum Complex,

ANGEWANDTE CHEMIE, Issue 4 2010
Shigeru Yamago Prof.
Vom Quadrat zum Kreis: Die selektive Synthese von [8]Cycloparaphenylen unter milden und neutralen Reaktionsbedingungen gelang in wenigen Stufen und hoher Ausbeute über das quadratförmige Biphenylplatin-Intermediat 1 (siehe Schema). 1 ist das kleinste bisher hergestellte Cycloparaphenylen. [source]

A Photoactivated trans -Diammine Platinum Complex as Cytotoxic as Cisplatin

CHEMISTRY - A EUROPEAN JOURNAL, Issue 11 2006
Fiona S. Mackay
Abstract The synthesis and X-ray structure (as the tetrahydrate) of the platinum(IV) complex trans,trans,trans -[Pt(N3)2(OH)2(NH3)2] 3 are described and its photochemistry and photobiology are compared with those of the cis isomer cis,trans,cis -[Pt(N3)2(OH)2(NH3)2] 4. Complexes 4 and 3 are potential precursors of the anticancer drug cisplatin and its inactive trans isomer transplatin, respectively. The trans complex 3 is octahedral, contains almost linear azide ligands, and adopts a layer structure with extensive intermolecular hydrogen bonding. The intense azide-to-platinum(IV) charge-transfer band of complex 3 (285 nm; ,=19,500,M,1,cm,1) is more intense and bathochromically shifted relative to that of the cis isomer 4. In contrast to transplatin, complex 3 rapidly formed a platinum(II) bis(5,-guanosine monophosphate) (5,-GMP) adduct when irradiated with UVA light, and did not react in the dark. Complexes 3 and 4 were non-toxic to human skin cells (keratinocytes) in the dark, but were as cytotoxic as cisplatin on irradiation for a short time (50 min). Damage to the DNA of these cells was detected by using the "comet" assay. Both trans- and cis -diammine platinum(IV) diazide complexes therefore have potential as photochemotherapeutic agents. [source]

Platinum Complexes of Aromatic Selenolates

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2010
Amy L. Fuller
Abstract Several synthetic methods are used to prepare naphthalene-based aromatic 1,2-diselenoles. A new one-pot synthesis starting from naphthalene is used to produce theknown compound naphtho[1,8- c,d][1,2]diselenole (Se2naph).Friedel,Crafts alkylation is used on Se2naph to substitute either one tert -butyl group to form 2- tert -butylnaphtho[1,8- c,d][1,2]diselenole (mt-Se2naph) or two tert -butyl groups to form 2,7-di- tert -butylnaphtho[1,8- c,d][1,2]diselenole (dt-Se2naph). Bromination of mt-Se2naph results in dibromination of the naphthalene ring, rather than reaction at selenium, to give 4,7-dibromo-2- tert -butylnaphtho[1,8- c,d][1,2]diselenole (mt-Se2naphBr2). Reduction of the Se,Se bond in Se2naph, mt-Se2naph, dibenzo[c,e][1,2]diselenine (dibenzSe2), or diphenyl diselenide (Se2Ph2) with LiBEt3 H, followed by in-situ addition of [PtCl2{P(OPh)3}2] yields the four-coordinate mono- and dinuclear platinum(II) bis(phosphite) complexes [Pt(Se2naph){P(OPh)3}2] (1), [Pt(mt-Se2naph){P(OPh)3}2] (2), [Pt2(dibenzSe2)2{P(OPh)3}2] (3), cis -[Pt(SePh)2{P(OPh)3}2] (4), and trans -[Pt2(SePh)4{P(OPh)3}2] (5). [source]

Copper, Cobalt and Platinum Complexes with Dithiothiophene-Based Ligands

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 16 2005
Dulce Belo
Abstract The preparation and characterisation of new thiophenedithiolate complexes of Cu, Co and Pt with the ligands ,-tpdt and tpdt (,-tpdt = 2,3-thiophenedithiolate, tpdt = 3,4-thiophenedithiolate) is reported. The Co and Pt complexes present regular square-planar coordination geometry and low oxidation potentials when compared with complexes with simpler ligands, but their monoanionic state is found to be rather unstable. The Co(tpdt)2 complex can be isolated both in the monoanionic and dianionic states as a stable compound but the Co(,-tpdt)2 and the Pt complexes can be obtained only in the dianionic state, while their monoanionic state is unstable. The Co and Pt complexes can, however, be easily oxidised to the neutral state, giving a fine-powdered microcrystalline material without high electrical conductivity. With Cu only a less frequent geometry based on a tetrametallic CuI cluster and three ligands is observed as [Cu4(,-tpdt)3]2, and [Cu4(tpdt)3]2,. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Synthesis of Novel gluco - and galacto -Functionalized Platinum Complexes,

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 28 2009
Janina Möker
Abstract Cisplatin, carboplatin, oxaliplatin and further derivatives are worldwide established cytostatics for the treatment of a vast range of tumours. These drugs showed extraordinary success; however, side effects and primary or developed secondary resistance of tumour cells represent severe problems, which prompt the development of novel functionalized platinum complexes. Selectively protected monohydroxy derivatives of glucose and galactose could be etherified by ,-halo ethers. Further, Finkelstein reaction and malonate synthesis gave precursor glycoconjugates which were easily transformed into their (diammine)platinum complexes. First tests with different tumour cell lines show biological activity of the gluco -functionalized platinum complex.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

NMR Spectra of Terminal Oxo Gold and Platinum Complexes: Relativistic DFT Predictions,

ANGEWANDTE CHEMIE, Issue 6 2010
Alessandro Bagno Prof.
NMR-Orakel: Relativistische Dichtefunktionalverfahren bilden eine zuverlässige Grundlage für Vorhersagen über die 195Pt-, 183W- und 17O-NMR-Spektren von Pt- und Au-Komplexen mit terminalen Oxoliganden (siehe Bild: [P2W20O70Au(O)(OH2)3]9,: Au,gelb, W,blau, P,orange, O,rot, N,blau, H,weiß). Die Komplexe verfügen über sehr kleine HOMO-LUMO-Abstände, und beide Orbitale sind je an einem MO-Fragment lokalisiert. [source]

ChemInform Abstract: Photogeneration of Nitrosyl Linkage Isomers in Octahedrally Coordinated Platinum Complexes in the Red Spectral Range.

CHEMINFORM, Issue 20 2010
Dominik Schaniel
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Platinum Complexes of Dibenzo[1,2]Dithiin, Dibenzo[1,2]Dithiin Oxides and Related Polyaromatic Hydrocarbon Ligands

CHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2006
Stephen M. Aucott Dr.
Abstract The synthesis of platinum bisphosphine complexes of biphenyl- 2,2,-dichalcogenates and the oxides of dibenzo[1,2]dithiin and related ligand systems by oxidative addition to [Pt(PPh3)4] is reported. We also describe the synthesis of a new compound, dibenzothiophen-4-yldiselenide and its simple platinum complex (obtained by oxidative addition). All complexes have been fully characterised, principally by using multinuclear NMR spectroscopy and in six cases by means of single-crystal X-ray diffraction studies. The majority are simple S/S or Se/Se complexes, however the addition of dibenzo[1,2]dithiin trioxide to [Pt(PPh3)4] gives a bimetallic system, [Pt{2-[S(O)],2,-[S(O)2]-biphen}(PPh3)]2, containing a central Pt2S2O2 core in which the ligand behaves as a tridentate S,S,O donor. [source]

Platinum Complexes of Naphthalene-1,8-dichalcogen and Related Polyaromatic Hydrocarbon Ligands

CHEMISTRY - A EUROPEAN JOURNAL, Issue 7 2004
Stephen M. Aucott Dr.
Abstract Platinum bisphosphine complexes bearing dichalcogen-derivatised naphthalene, acenaphthene or phenanthrene ligands have been prepared by either oxidative addition to zero-valent platinum species or from [PtCl2(PPhR2)] (R=Ph or Me) and the disodium or dilithium salts of the parent disulfur, diselenide or mixed S/Se species. The parent naphthalene, acenaphthene and phenanthrene chalcogen compounds were treated with either [Pt(PPh3)4] or [Pt(C2H4)(PMe3)2] (prepared in situ from [PtCl2(PMe3)2], ethene and sodium naphthalide or super hydride [LiBEt3H]) to give the appropriate platinum(II) species. The dilithium salts of 1,8-E2 -naphthalene (E=S or Se) prepared in situ by reduction of the EE bond with [LiBEt3H] were treated with [PtCl2(PPh3)2] to give [Pt(1,8-E2 -nap)(PPh3)2]. The tetraoxides [Pt(1,8-(S(O)2)2 -nap)(PR3)2] (PR3=PPh3 or PMe2Ph) were prepared in a similar metathetical manner from the appropriate [PtCl2(PR3)] complexes and the disodium salt of naphthalene 1,8-disulfinic acid (1,8-(S(O)ONa)2 -nap). The X-ray structures of selected examples reveal bidentate coordination with the naphthalene-E2 unit hinged (111,137°) with respect to the coordination plane. The naphthalene ring suffers significant distortion from planarity. [source]

Synthesis and Properties of para -Substituted NCN-Pincer Palladium and Platinum Complexes

CHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2004
Martijn Q. Slagt Dr.
Abstract A variety of para -substituted NCN-pincer palladium(II) and platinum(II) complexes [MX(NCN-Z)] (M=PdII, PtII; X=Cl, Br, I; NCN-Z=[2,6-(CH2NMe2)2C6H2 -4-Z],; Z=NO2, COOH, SO3H, PO(OEt)2, PO(OH)(OEt), PO(OH)2, CH2OH, SMe, NH2) were synthesised by routes involving substitution reactions, either prior to or, notably, after metalation of the ligand. The solubility of the pincer complexes is dominated by the nature of the para substituent Z, which renders several complexes water-soluble. The influence of the para substituent on the electronic properties of the metal centre was studied by 195Pt NMR spectroscopy and DFT calculations. Both the 195Pt chemical shift and the calculated natural population charge on platinum correlate linearly with the ,p Hammett substituent constants, and thus the electronic properties of predesigned pincer complexes can be predicted. The ,p value for the para -PtI group itself was determined to be ,1.18 in methanol and ,0.72 in water/methanol (1/1). Complexes substituted with protic functional groups (CH2OH, COOH) exist as dimers in the solid state due to intermolecular hydrogen-bonding interactions. Een verscheidenheid aan para-gesubstitueerde NCN-pincer-palladium(II) en -platina(II) complexen [MX(NCN-Z)] (M=PdII, PtII; X=Cl, Br, I; NCN-Z=[2,6-(CH2NMe2)C6H2 -4-Z],; Z=NO2, COOH, SO3H, PO(OEt)2, PO(OH)(OEt), PO(OH)2, CH2OH, SMe, NH2) is gesynthetiseerd via substitutiereacties zowel voor, en hoogst opmerkelijk, ook na de metallering van het ligand. De oplosbaarheid van de pincer-complexen wordt gedomineerd door de aard van de para -substituent Z, waardoor enkele van de complexen wateroplosbaar zijn. De invloed van de para -substituent op de elektronische eigenschappen van het metaalcentrum is bestudeerd met behulp van195Pt-NMR en DFT-berekeningen. Zowel de chemische verschuiving van de195Pt-kern, als de berekende ,natural population, lading op platina vertonen een lineaire correlatie met de ,pHammett-substituentconstante, hetgeen het voorspellen van de elektronische eigenschappen van nieuwe pincercomplexen mogelijk maakt. De ,p -waarde van de para-PtI eenheid blijkt respectievelijk ,1.18 in methanol en ,0.72 in waterige methanol (1/1, v/v) te zijn. Door de aanwezigheid van intermoleculaire waterstofbruggen komen de complexen met protische functionele groepen (CH2OH, COOH) in de vaste stof voor als dimeren. [source]

Synthesis, Structures, and Electronic Spectroscopy of Luminescent Acetylene- and (Buta-1,3-diyne)platinum Complexes

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2007
Ke Zhang
Abstract The electronic absorption and emission spectroscopy of a series of diphenylaceylene- and (buta-1,3-diyne)-Pt0 complexes (L)Pt[(1,2-,2)-R,(C,C)n,R] and [(dppp)Pt]2[,-(1,2-,2):(3,4-,2)-R,(C,C)2,R] {R = Ph or CH3, L = dppp or(PPh3)2, n = 1 or 2} was investigated. The structures of(dppp)Pt[(1,2-,2)-Ph,C,C,Ph], (dppp)Pt[(1,2-,2)-PhC4Ph] and [(dppp)Pt]2[,-(1,2-,2):(3,4-,2)-Ph,(C,C)2,Ph] were characterized by X-ray diffraction. The complexes all display intense absorptions that were attributed to Pt,P(d,*) and Pt,acetylene(,x*) transitions. Except for the CH3C4CH3 complexes, the complexes all exhibit two emissions at 380,550 nm and 500,800 nm. The higher energy emission could arise from the 3[P(d,*),Pt] transition, and the lower energy emission, which has a longer lifetime than the higher energy one, was attributed to the 3[acetylene(,x*),Pt] transition. The energy of the MLCT absorption and emission was affected by the electronic properties of the acetylenes and the ancillary phosphanes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

Formation of (,-Alkenyl)- and (,-Vinylidene)palladium and -platinum Complexes by Oxidative Addition of 4,4-Dichloro-1,1-diphenyl-2-azabuta-1,3-diene , The Molecular Structure of an Unusual Asymmetric (,-Vinylidene)Pd,Pd Complex

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2003
Michael Knorr
Abstract 4,4-Dichloro-1,1-diphenyl-2-azabuta-1,3-diene (1) oxidatively adds to [Pd(PPh3)4] and [Pt(C2H4)(PPh3)2] giving rise to the ,-alkenyl complexes trans -[MCl{[C(Cl)=C(H),N=CPh2]}(PPh3)2] (2a: M = Pd; 2b: M = Pt). When 1 is treated with [Pd(PPh3)4] in a 1:2 ratio in refluxing toluene, the dimetallic ,-vinylidene complex [(PPh3)ClPd{,-[C=C(H),N=CPh2]}PdCl(PPh3)2] (3) is formed. In this fluxional compound, a PPh3 ligands migrates in a reversible manner between the two Pd centers. Substitution of the PPh3 ligands of 3 by 2 equiv. of Ph2PCH2PPh2 affords the A-frame complex [ClPd(,-dppm)2{,-[C=C(H),N=CPh2]}PdCl] (4). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Site-Selective Ser-Hydrolase Labelling with a Luminescent Organometallic NCN,Platinum Complex

New Coordination Modes of L -Ascorbic Acid and Dehydro- L -ascorbic Acid as Dianionic Chelating Ligand for Platinum

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2008
Paola Bergamini
Abstract A variety of coordination modes of L -ascorbic acid as an anionic bidentate ligand has been exploited to prepare platinum(II) complexes 1,7 that contain phosphanes or R,R -dach (1R,2R -diaminocyclohexane) as neutral ligands in which O2, O3, O5, O6 and C2 act as anionic donating functionalities. An alternative synthetic route to known O2,O3 complexes is proposed, and their solubility in water has been enhanced by introducing PTA (1,3,5-triaza-7-phosphaadamantane) as a neutral ligand. A new coordination mode of ascorbic acid (O2 and O3 protected) as an O5,O6-diolate chelating ligand has been characterised in solution by NMR spectroscopy and in the solid state by X-ray crystallography. The first example of a platinum complex that contains dehydroascorbic acid, 7, has also been prepared and its X-ray crystal structure has been determined. The antiproliferative activity in vitro of complexes 1,7 has been tested, and the best values were obtained for the DHA complex 7, which was found to be more active than cisplatin on both a cisplatin-sensitive and a cisplatin-resistant cell line.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Catalytic behaviors of silica-supported methylcellulose- L -phenyl alanine,platinum complexes in asymmetric hydrogenation of diacetone alcohol

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3-4 2002
Kai Huang
Abstract A new chiral natural bio-polymer,metal complexe, silica-supported methylcellulose- L -phenyl alanine,platinum complex (SiO2 -MC- L -Phe,Pt) has been prepared by a very simple method, and the Pt complex has been found to be able to catalyze the asymmetric hydrogenation of diacetone alcohol to give (R)-(,)-2-methyl-2,4-pentandiol at room temperature and under atmospheric hydrogen pressure. The product and optical yields of 2-methyl-2,4-pentandiol amounted to 67.0 and 92.7%, respectively. The product and optical yields were remarkably affected by the Pt content in the complex, the kind of solvent and the reaction temperature. This catalyst was very stable and could be reused several times without any remarkable change in optical catalytic activity. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Intra-hepatic arterial administration with miriplatin suspended in an oily lymphographic agent inhibits the growth of human hepatoma cells orthotopically implanted in nude rats

CANCER SCIENCE, Issue 1 2009
Mitsuharu Hanada
Miriplatin is a lipophilic platinum complex which contains myristates as leaving groups and diaminocyclohexane as a carrier ligand. In order to examine in vivo the antitumor activities of miriplatin suspended in an oily lymphographic agent (Lipiodol Ultra-Fluide®, LPD) against human hepatocellular carcinoma (HCC) after the intra-hepatic arterial administration, we have developed a novel orthotopic model of HCC in which the human hepatoma cell line Li-7 was successively implanted and maintained in the liver of nude rats. Li-7 tumors established in nude rat livers displayed a trabecular structure similar to their original morphology, and were exclusively supplied by the hepatic artery, suggesting that they exhibited in part the conditions of human HCC. Miriplatin suspended in LPD (miriplatin/LPD) administered into the hepatic artery of this model dose-dependently inhibited the growth of Li-7 tumors without markedly enhancing body weight loss and caused a significant reduction in the growth rate at a dose of 400 µg/head compared to LPD alone. In addition, at the therapeutic dose, miriplatin/LPD as well as cisplatin suspended in LPD (400 µg/head) was shown to be more active than zinostatin stimalamer suspended in LPD (20 µg/head) against Li-7 tumors after a single intra-hepatic arterial administration. These results suggest miriplatin to be a suitable candidate for use in transarterial chemoembolization (Cancer Sci 2009; 100: 189,194) [source]

Preparation of Pt,Ru Alloyed Thin Films Using a Single-Source CVD Precursor,

CHEMICAL VAPOR DEPOSITION, Issue 3 2003
S.-F. Huang
Abstract Treatment of (dimethylaminomethyl)ruthenocene with cis -Pt(DMSO)2Cl2 led to the formation of a ruthenocenyl platinum complex [CpRu(,5 -C5H3CH2NMe2)Pt(DMSO)Cl] (1); subsequent treatment of 1 with [Na(hfac)] afforded an air-stable Pt,Ru complex [CpRu(,5 -C5H3CH2NMe2)Pt(hfac)] (2). Its volatility and other physical data relevant to CVD experiments were assessed by thermogravimetric analysis (TGA). The Pt,Ru thin films were then deposited at two deposition temperatures, 300,°C and 400,°C, using O2 as the reactive carrier gas. The as-deposited thin films were characterized using energy dispersive X-ray (EDX), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Results indicated the formation of a homogeneous Pt,Ru solid solution at the lower deposition temperature. However, upon raising the temperature to 400,°C, phase separation between Pt and Ru occurred, which then induced the growth of RuO2 grains at the substrate surface and caused depletion of the alloy in ruthenium. The electrocatalytic activities of the films, in respect of methanol oxidation, were investigated, in half-cell experiments, by cyclic voltammetry. [source]

Platinum Complexes of Dibenzo[1,2]Dithiin, Dibenzo[1,2]Dithiin Oxides and Related Polyaromatic Hydrocarbon Ligands

Metal Effects on the Asymmetric Synthesis of a New Heterobidentate As/P=S Ligand

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2010
Mengtao Ma
Abstract The cycloaddition reaction between 3,4-dimethyl-1-phenylarsole and diphenylvinylphosphane sulfide was promoted by chiral palladium and platinum complexes containingortho -metalated (S)-[1-(dimethylamino)ethyl]naphthalene. They exhibited similar stereoselectivity; the palladium cycloadducts could not be separated via column chromatography and fractional crystallization, however, the corresponding platinum complexes could be successfully converted into their enantiomerically pure counterpart. A formal arsanylidene elimination reaction was observed on the liberated free As/P=S bidentate ligand. [source]

Click Chelators for Platinum-Based Anticancer Drugs

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2008
Aurélie Maisonial
Abstract Triazoles from "click chemistry" are convenient ligands for the formation of platinum complexes bearing combined triazole,amine or triazole,carboxylate moieties. Striking differences in the chelation modes are observed between the two series. One of the triazole,amine platinum complexes exhibits selective cytotoxicity against breast cancer cells lines. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Application of Gel-Phase 195Pt NMR Spectroscopy in a Novel Solid-Phase Synthesis of a Primary Amine Dichloroplatinum(II) Complex

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2003
Marc S. Robillard
Abstract Gel-phase 195Pt NMR spectroscopy of dichloroplatinum peptide complexes attached to a solid support is described. The observed 195Pt chemical shifts of the support-bound platinum complexes are in good agreement with the solution-state 195Pt NMR spectra of the soluble and deprotected analogs. This non-destructive analytical method for on-resin-compound analysis was applied in the optimization of the solid-phase synthesis of the primary amine dichloroplatinum complex 6, which represents a new class of platinum complexes now available via solid-phase synthetic chemistry. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Synthesis of Novel gluco - and galacto -Functionalized Platinum Complexes,

A new family of platinum(II) complexes incorporating five- and six-membered cyclic phosphine ligands

HETEROATOM CHEMISTRY, Issue 2 2010
Andrea Kerényi
New platinum complexes of the type cis -Pt(L)2Cl2 have been synthesized from five- and six-membered cyclic phosphines, which were prepared after deoxygenating a series of phosphine oxides (3-phospholene oxides, phospholane oxides, a 1,4-dihydrophosphinine oxide, and a 1,2,3,6-tetrahydrophosphinine oxide). The complexes were characterized by NMR and mass spectral data, and their stereostructures were elucidated by B3LYP/6-31G(d)-LANL2DZ ECP calculations. The phosphine intermediates were characterized as the corresponding phosphine-boranes. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:63,70, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20579 [source]

Synthesis and reactivity of sulfonamides containing boronate esters

HETEROATOM CHEMISTRY, Issue 5 2004
Xiao-Feng He
Sulfonamides containing pinacol protected boronate ester groups have been prepared by the addition of H2NC6H4Bpin (pin = O2C2Me4) to sulfonyl chlorides p -RC6H4SO2Cl (R = CH3, NO2). Hydrogenation of the nitro derivatives afford the corresponding sulfanilamides without compromising the aryl-Bpin bond. The sulfanilamides were further functionalized to afford novel platinum complexes containing boranosulfonamides. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:369,375, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20025 [source]

Trafficking and localization of platinum complexes in cisplatin-resistant cell lines monitored by fluorescence-labeled platinum,

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2005
Xing-Jie Liang
Cisplatin is a chemotherapeutic agent commonly used in the treatment of a wide variety of malignant tumors. Resistance to cisplatin represents a major obstacle to effective cancer therapy because clinically significant levels of resistance quickly emerge after treatment. Based on previous studies indicating abnormal plasma membrane protein trafficking in cisplatin-resistant (CP-r) cells, Fluorescence (Alexa Fluor)-labeled cisplatin was used to determine whether this defect altered the trafficking and localization of cisplatin by comparing drug sensitive KB-3-1 and KB-CP-r cells. Alexa Fluor,cisplatin was readily internalized and localized throughout the KB-3-1 cells, but overall fluorescence decreased in KB-CP-r cells, as detected by flow cytometry (FACS) and confocal microscopy. Only punctate cytoplasmic staining was observed in KB-CP-r cells with less fluorescence observed in the nucleus. Colocalization experiments with a Golgi-selective stain indicate the involvement of Golgi-like vesicles in initial intracellular processing of Alexa Fluor conjugated cisplatin complexes. As detected using an antibody to Alexa Fluor,cisplatin, cisplatin complex-binding proteins (CCBPs) were reduced in membrane fractions of single-step cisplatin-resistant KB-CP.5 cells, and increased in the cytoplasm of KB-CP.5 cells compared to KB-3-1 cells. CCBPs localized to lower density fractions in KB-CP.5 cells than in KB-3-1 cells as determined by iodixanol gradient centrifugation. In summary, inappropriate trafficking of CCBPs might explain resistance to cisplatin in cultured cancer cells, presumably because membrane binding proteins for cisplatin are not properly located on the cell surface in these cells, but are instead trapped in low density vesicles within the cytoplasm. © 2004 Wiley-Liss, Inc. [source]

Catalytic behaviors of silica-supported methylcellulose- L -phenyl alanine,platinum complexes in asymmetric hydrogenation of diacetone alcohol

Comparison of collision- versus electron-induced dissociation of Pt(II) ternary complexes of histidine- and methionine-containing peptides,

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 19 2009
Linda Feketeová
Incubation of the histidine-containing peptides (GH, HG, GGH, GHG, HGG) and methionine-containing peptides (GM, MG, GGM, GMG, MGG) with the platinum complexes [Pt(terpy)Cl]+ (A) and [Pt(dien)Cl]+ (B) followed by electrospray ionisation (ESI) led to a number of singly and doubly charged ternary platinum peptide complexes, including [Pt(L)M]2+ and [Pt(L)M,H]+ (where L,=,the ligand terpy or dien; M is a peptide). Each of the [Pt(L)M]2+ complexes was subjected to electron capture dissociation (ECD), collision-induced dissociation (CID) and electron-induced dissociation (EID), while each of the [Pt(L)M,H]+ complexes was subjected to CID and EID. Results from ECD suggest that the free electron is captured by the metal ion thus weakening the bonds to its ligands. In the case of the ligand terpy, which binds more strongly than dien, this weakening leads to the loss of the peptide. The minor products in the ECD spectra of [Pt(terpy)M]2+ complexes do show fragmentation along the peptide backbone, but the ions observed are of the a-, b-, and y-type. For the complexes with methionine-containing peptides, a marker ion, [Pt(L)SCH3]+, was found which is indicative of binding of Pt to the methionine side chain. For the histidine-containing peptides, an ion containing platinum, the auxiliary ligand, and the histidine imine was observed in many instances, thus indicating the binding of the histidine side chain to the metal, but other modes of Pt coordination (N-terminus) were also found to be competitive. These findings are consistent with a recent finding (Sze et al. J. Biol. Inorg. Chem. 2009; 14: 163) that Pt occupies the methionine-rich copper(I)-binding site rather than histidine-rich copper(II)-binding site in the CopC protein. Copyright © 2009 John Wiley & Sons, Ltd. [source]