10199-34-5Relevant articles and documents
Eaborn, Colin,Pidcock, Alan,Steele, Barry H.
, (1976)
DEPROTONATION REACTIONS BY TRANSITION-METAL PEROXO-COMPLEXES. SYNTHESIS OF AROYLHYDRAZIDO- AND AROYLHYDROXYLAMIDO-COMPLEXES OF PALLADIUM AND PLATINUM AND THE CRYSTAL AND MOLECULAR STRUCTURES OF AND
Bellon, Pier Luigi,Cenini, Sergio,Demartin, Francesco,Manaserro, Mario,Pizzotti, Maddalena,Porta, Francesca
, p. 2060 - 2067 (1980)
By treating (M = Pd or Pt) with C6H5C(O)NHOH, C6H5(NH)NHOH, and p-RC6H4C(O)NHNH2 in ethanol, the complexes , , and (R = H, CH3, or NO2) respectively have been obtained.The reactions of with RNHNH2 (R = H or C6H5) lead only to the zerovalent complex, , while by treating with C6H5NHOH the known complex is obtained.Reactions of the aroylhydrazidoplatinum complexes with molecular oxygen and mineral acids are also reported.The structure of the two title complexes has been determined by X-ray diffraction.The compound is orthorhombic and crystallizes in space group Pna21 with a = 17.365(6), b = 11.218(7), and c = 18.431(8) Angstroem, whereas the disordered is monoclinic and crystallizes in space group P2n1/m with a = 15.829(6), b = 12.269(5), c = 11.833(5) Angstroem, and β = 93.51(3) deg.Both structures have been solved by Patterson and Fourier methods, and refined to R 0.031 and 0.062 for 2057 and 2119 independent reflections, respectively.Both compounds, in the solid state, are essentially square-planar complexes of PtII.The differences between the two structures, which display different packing efficiency, are mainly due to the conformations of the phosphine groups, which are imposed by the chelating ligands.
Trans-cis isomerization of [(C6H5)3P]2PtCl2 complex in dimethylformamide solutions
Jacewicz, Dagmara,Pranczk, Joanna,Wyrzykowski, Dariusz,?amoj?, Krzysztof,Chmurzyński, Lech
, p. 620 - 624 (2014)
The kinetics of the trans-cis isomerization reactions of the [(C6H5)3P]2PtCl2 neutral complex catalyzed by four different metal ions: Be2+, Mg2+, Ca2+ and Sr2+ has been studied. The isomerization reactions were investigated in dimethylformamide (DMF) solutions at five temperatures in the range of 278-298 K keeping a constant concentration of metal ions c = 0.5 M. The rates of the isomerization reactions were determined spectrophotometrically by monitoring the absorbance changes at the 277 nm wavelength. The spectral measurements were carried out in the UV-Vis region using the Perkin-Elmer Lambda 650 instrument with the scan accuracy of 1 nm and 1 nm slit width at the 120 scanning rate. The observable rate constants were computed using the Glint program based on the global analysis. The activation energies were determined using the Arrhenius equation. The differences in the structures of the obtained cis and trans geometric isomers were confirmed on the basis of their IR spectra.
From NHC to Imidazolyl Ligand: Synthesis of Platinum and Palladium Complexes d10-[M(NHC)2] (M = Pd, Pt) of the NHC 1,3-Diisopropylimidazolin-2-ylidene
Hering, Florian,Radius, Udo
, p. 3236 - 3245 (2015)
The widely held belief that N-heterocyclic carbenes (NHCs) act only as innocent spectator ligands is not always accurate, even in the context of well-explored reactions. Ligand exchange in the conversion of [Pt(PPh3)2(I2-C2H4)] (3) to [Pt(iPr2Im)2] (2) depends critically on the particular reaction conditions employed, with slight changes leading to vastly different outcomes. In addition to [Pt(iPr2Im)2] (2), complexes [Pt(iPr2Im)(PPh3)(I2-C2H4)] (5) and trans-[Pt(iPr2Im)2(iPr-Im)(H)] (6) were isolated and in the case of 6 fully characterized. Complex 5 represents the first mixed-olefin complex in transition metal chemistry containing both an NHC and a phosphine ligand. Chemical degradation of the NHC was shown to yield the new imidazole-2-yl iPr-Im? in 6. Therefore, the synthesis of [Pt(iPr2Im)2] (2) via metallic reduction of the ionic precursor [Pt(iPr2Im)3(Cl)]+Cl- (9) is favorable, a procedure adaptable to analogous palladium compounds. While [Pd(iPr2Im)3(Cl)]+Cl- (8) is the only product obtained from the reaction of iPr2Im and PdCl2, neutral [Pt(iPr2Im)2(Cl)2] (10), formed as a mixture of its two stereoisomers cis-10 and trans-10, is available through precise control of the stoichiometry in the reaction of PtCl2 and exactly 2 equiv of iPr2Im.
Synthesis and reactivity of cis-dichloro(enamine)(amine)platinum(II) complexes
Doran, Sheryl L.,Brown, David B.,Allen, Christopher W.
, p. 111 - 118 (1988)
The reaction of Zeise's dimer, trans-μ-dichlorobis(ethylene)platinum(II) chloride, with a variety of alkyl-substituted enamines led to complexes of the type cis-, where the enamine ligand is coordinated to the platinum(II) center through its nucleophilic carbon atom (C(2)) and the amine ligand is derived from the parent enamine.Analogous palladium complexes were prepared.The complexes were characterized by elemental analysis, NMR (1H, 13C), and IR spectroscopy.Addition of 1 equiv.Ph3P to cis- resulted in substitution of the enamine ligand by Ph3P.When 2 equiv.Ph3P were added, both the enamine and amine ligands were replaced.Hydrolysis of cis- in dilute acetic acid resulted in formation of cis-, through enamine hydrolysis.Possible mechanisms for these reactions and for the formation of the complexes are discussed.
5-Aminoorotic acid, a versatile ligand with the ability to exhibit differing co-ordination and hydrogen-bonding modes: Synthesis and crystal structures of platinum(II) complexes
Burrows, Andrew D.,Mingos, D. Michael P.,White, Andrew J. P.,Williams, David J.
, p. 3805 - 3812 (1996)
The complex [Pt(cod)Cl2] (cod = cycloocta-1,5-diene, C8H12) reacted with 2 equivalents of PPh3 and an excess of 5-aminoorotic acid (5-amino-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H4L) in the presence of silver(I) oxide to give two isomers of [Pt(PPh3)2(H2L)] 1 and 2. Complexes 1 and 2 can be separated by fractional crystallisation but, in CDCl3 solution, each slowly converts into an equilibrium mixture of the two. Crystal structure determinations have shown that in both 1 and 2 the 5-aminoorotate ligand coordinates to the platinum atom as a dianion. In 1 this is achieved via deprotonation of the carboxylic acid and the loss of an amino NH2 proton, leading to a six-membered chelate ring, whereas in 2 it is by deprotonation of the carboxylic acid and loss of the amido proton, leading to a five-membered chelate ring. This difference in co-ordination mode leads to a difference in the orientation of the hydrogen-bond donors and acceptors remaining on the ligand which, in turn, leads to different supramolecular structures, dimers for 1 and tetramers for 2, with the latter structurally similar to guanine tetrads. These naturally occurring units are stabilised by alkali-metal ions, but reaction of 2 with a compound such as NaBF4 in a two-phase dichloromethane-water system led to [Pt2(PPh3)4(HL)][BF4] as the only platinum-containing product. A crystal structure determination showed that in this complex the ligand is trianionic, deprotonated at the carboxylic acid and both the amido and amino nitrogen atoms, co-ordinating to two platinum atoms via five- and six-membered chelate rings. When dppe [1,2-bis(diphenylphosphino)ethane] was used instead of PPh3 only one isomer of [M(dppe)(H2L)] (M = Pt 3 or Pd 4) was observed for both platinum and palladium, containing the five-membered chelate ring.
OXIDATION VON DICHLORMETHAN ZU EINEM CARBONAT-LIGANDEN
Scherer, O. J.,Jungmann, H.,Huessong, K.
, p. C1 - C4 (1983)
The reaction of CH2Cl2 with (Ph3P)2PtO2 affords cis-(Ph3P)2PtCl2, (Ph3P)2Pt(CO3), Ph3PO and H2O. 31P NMR studies of this oxidation of CH2Cl2 to a carbonato ligand give evidence for the intermediates (Ph3P)2Pt(OOCH2Cl)Cl and .With formic acid (Ph3P)2PtO2 yields the formate complex cis.
Addition of tetrachloromethane to alkenes, catalyzed by Pt(II) complexes
Zazybin,Khusnutdinova,Osipova,Solomonov
, p. 734 - 738 (2005)
Platinum(II) complexes [dichlorobis(triphenylphosphine)platinum(II), dichlorobis(tri-m-tolylphosphine)platinum(II), dichloro(2,9-dimethyl-1,10-N, N′-phenanthroline)platinum(II), etc.] showed catalytic activity in addition of tetrachloromethane across the double bond in 1-hexene, 1-heptene, 1-octene, 1-decene, and cyclohexene. The stability of the platinum catalysts was evaluated by GLC, gas chromatography-mass spectrometry, and 31P NMR and IR spectroscopy; the kinetic relationships of the addition reactions were determined. A reaction mechanism involving formation of trichloromethyl radical was suggested. A correlation was revealed for the first time between the catalytic activity of platinum, palladium, and rhodium complexes and the capability of these complexes to generate hexachloroethane. 2005 Pleiades Publishing, Inc.
Supramolecular bidentate phosphorus ligands based on bis-zinc(ii) and bis-tin(iv) porphyrin building blocks
Slagt, Vincent F.,Van Leeuwen, Piet W. N. M.,Reek, Joost N. H.
, p. 2302 - 2310 (2007)
Selective metal-ligand interactions have been used to prepare supramolecular bidentate ligands by mixing monodentate ligands with a suitable template. For these assemblies pyridine phosphorus ligands and a zinc(II) porphyrin dimer were used. In the rhodium-catalysed hydroformylation of 1-octene and styrene improved selectivities have been obtained for some of the assembled bidentate ligand systems. In the palladium catalysed asymmetric allylic alkylation similar effects were observed; the enantioselectivity increased by using a bisporphyrin template. The preparation of supramolecular catalyst systems was also explored using tin-oxygen interactions. Dihydroxotin(iv) porphyrin and carboxylic phosphorus ligands assemble into supramolecular ligands and the phosphorus donor atom coordinates to transition metals. The stronger oxygen-tin bond, compared to pyridine-zinc does not result in a better performance of the catalyst. The Royal Society of Chemistry.
Suzuki, Keinosuke,Yamamoto, Hisashi
, p. 225 - 230 (1993)
Synthesis, structure and reactivity of N,O-metallacyclic (dicarbonyldiazene) platinum complexes
Chan, Danny,Cronin, Leroy,Duckett, Simon B.,Hupfield, Peter,Perutz, Robin N.
, p. 511 - 516 (1998)
Reaction of cis-Pt(PR13)2Cl2 (R1 = Me, Ph) with diacyl hydrazine R2OCNHNHCOR2 (R2 = Me, Ph) in refluxing ethanol and NaHCO3 afforded platinum diazene diacyl complexes Pt(PR13)2(R2OCNNCOR2) (1, R1 = R2 = Ph; 3, R1 = Me, R2 = Ph; 4, R1 = R2 = Me). Reaction of Pt(PPh3)2(C2H4) with diazene dicarboxylates R2OCNNCOR2 (R2 = OEt, OPri) resulted in the formation of Pt(PPh3)2(R2OCNNCOR2) (2, R2 = OEt; 5, R2 = OPri). Multinuclear NMR spectroscopy on 1-5 revealed that the dicarbonyl-substituted diazene ligand is coordinated asymmetrically, consistent with a five membered Pt-N-N-C-O ring. Compound 5 crystallises from THF-benzene as the solvate Pt(PPh3)2(PriO2CNNCO 2Pri)·(C6H6)2; its X-ray crystal structure shows that the coordination sphere of platinum is essentially square planar and coplanar with the five membered Pt1-O1-C5-N2-N1 ring. The Pt1-O1 distance is 2.027(4) A and the Pt1-N1 distance is 2.050(5) A. The N1-N2 distance is 1.421(6) A while the N2-C5 and C5-O1 distances are 1.273(7) and 1.314(7) A, respectively. Complexes 1-5 show sensitivity towards chlorinated solvents (CH2Cl2, CHCl3) under photolysis conditions, forming the corresponding cis-platinum bis(phosphine) dichloride complexes; the same products are formed in a slower thermal reaction with 2 and 5. Complexes 2 and 5 react photochemically with ethylene in [2H8]THF yielding Pt(PPh3)2(C2H4) but 1, 3 and 4 are inert. Addition of an excess of dppe ligand to 2 and 5 resulted in the displacement of PPh3 and the formation of Pt(dppe)(EtO2CNNCO2Et) and Pt(dppe)(PriO2CNNCO2Pri) [dppe = 1,2-bis(diphenylphosphino)ethane].
Further Approaches in the Design of Antitumor Agents with Response to Cell Resistance: Looking toward Aza Crown Ether-dtc Complexes
Arenaza-Corona, Antonino,Barba, Victor,Couce-Fortúnez, M. Delfina,De Blas, Andrés,H?pfl, Herbert,Morales-Morales, David,Rodríguez-Blas, Teresa,Santillan, Rosa
, p. 15120 - 15134 (2020)
The dianionic aza crown ether-dtc N,N′-bis(dithiocarbamate)-1,10-diaza-18-crown-6 (L2-) is a versatile ligand capable of yielding binuclear complexes with group 10 elements, also known as Ni-triade, [μ-(κ2-S,-S′-L)M2(PPh3)4]Cl2 (M = Pd (1), Pt (2)), [μ-(κ2-S,-S′-L)M2(PPh3)4](BPh4)2 (M = Pd (3), Pt (4)), and μ-(κ-S,-S′-L)Ni2(PPh3)2Cl2 (5), and has proven to be an excellent option to the design of metal-based drugs able to provide multiple response to cell resistance. Palladium and platinum complexes, 1 and 2, were tested for cytotoxicity in the human cervix carcinoma cell line HeLa-229, the human ovarian carcinoma cell line A2780, and the cisplatin-resistant mutant A2780cis, finding significant activity toward all three cancer cell lines, with low micromolar IC50 values, comparable to cisplatin. Markedly, against the cisplatin resistant cell line A2780cis, compound 2 exhibits better cytotoxic activity than the clinical drug (IC50 = 2.3 ± 0.2 μM for 2 versus 3.6 ± 0.5 μM for cisplatin). Moreover, an enhancement of the antitumor response is achieved when adding an equimolar amount of alkali metal chloride (NaCl or KCl) to the medium, for instance, testing compound 1 against the cisplatin-resistant A2780cis cells, the IC50 decreases from 9.3 ± 0.4 to 7.4 ± 0.3 and 5.4 ± 0.1 μM, respectively, after addition of the salt solution. For the platinum derivative 2, the IC50 improves by ca. 40% reaching 1.3 ± 0.1 μM when potassium chloride is added. Likewise, the resistant factor found for 2 (RF = 1) confirms that this complex circumvents cisplatin-resistance in A2780cis and is improved with the addition of potassium chloride (RF = 0.65). The presence of the aza crown ether moiety as linker in the systems studied herein is a key point since, in addition to allowing and facilitating interaction with alkali metal ions, this unit is flexible enough to adapt to a variety of environments, as confirmed by the X-ray crystal structures described, where different conformations and ways to fold in are found. In order to gain insight into the electronic and structural facts involved in the interaction of complex 2 with the alkali metal ions, a DFT study was performed, and the description of the molecular electrostatic potentials (MEPs) is also presented.
The coordination chemistry of sulfonyl-substituted thioureas towards the d8 metal centres platinum(II), palladium(II), nickel(II) and gold(III)
Henderson, William,Risi, Matthew C.,Saunders, Graham C.
, (2021)
Reactions of the complexes cis-[PtCl2(PPh3)2], [PtCl2(dppp)] (dppp = Ph2P(CH2)3PPh2), [MCl2(dppe)] (dppe = Ph2P(CH2)2PPh2, M = Ni, Pd), [PdCl2(bipy)] (bipy = 2,2′-bipyridine) and [AuCl2(bp)] (bp = cyclometallated 2-benzylpyridine) with p-TolSO2NHC(S)NHPh and Et3N in refluxing methanol gave a series of new thiourea complexes containing the ligand bound as a dianion through the S and the NPh groups. The related thioureas RSO2NHC(S)NHPh (R = Me, Et) and p-TolSO2NHC(S)NHCH2CH=CH2 were also reacted with cis-[PtCl2(PPh3)2] to form the corresponding complexes [Pt{RSO2NC(S)NPh}(PPh3)2] and [Pt{TolSO2NC(S)NCH2CH=CH2}(PPh3)2] respectively. X-ray structure determinations were carried out on the thiourea MeSO2NHC(S)NHPh and its platinum complex [Pt{MeSO2NC(S)NPh}(PPh3)2], as well as [Pt{TolSO2NC(S)NPh}(PPh3)2]. Both complexes form the distal isomer with a remote NSO2R group, and no evidence was observed for isomerisation of these platinum complexes in solution. The palladium complexes [Pd{TolSO2NC(S)NPh}L2] [L2 = Ph2PCH2CH2PPh2 (dppe), or 2,2′-bipyridine (bipy)] undergo decomposition in solution to form the sulfide-bridged aggregates [Pd3S2(L2)3]2+, identified by ESI MS and 31P NMR.
Al-Ahmad, S.,Hudali, H.,Zaghal, M. H.
, p. 1 - 2 (1988)
Pyrrole thioamide complexes of the d8 metals platinum(II), palladium(II) and gold(III)
Tang, Haiming,Saunders, Graham C.,Ma, Xiaochuan,Henderson, William
, (2019/12/09)
Reactions of the cycloaurated gold(III) complexes [AuCl2(2-benzylpyridyl)] and [AuCl2(C6H4CH2NMe2)] with a set of pyrrole-2-thioamide ligands, containing various substituents on the pyrrole ring, gave a series of new gold(III) pyrrole thioamide complexes. X-ray crystal structures on two complexes indicate that the pyrrole thioamide ligand is coordinated through the deprotonated pyrrole nitrogen, as well as the sulfur atom of the deprotonated thioamide group, forming five-membered chelate ring complexes. In both complexes, the two highest trans-influence donor atoms (C and S) are mutually cis. Related sets of platinum(II) and palladium(II) pyrrole thioamide complexes were similarly prepared by reactions of cis-[PtCl2(PPh3)2] and [PdCl2(dppe)] (dppe = Ph2PCH2CH2PPh2)] respectively. The complexes were characterised by NMR and IR spectroscopies, and ESI mass spectrometry. A preliminary investigation of the activity of a selection of compounds towards A549 (adenocarcinomic human alveolar basal epithelial) cells was also carried out.
