15604-36-1Relevant articles and documents
In Vitro Anticancer Activity of Nanoformulated Mono- and Di-nuclear Pt Compounds
Wang, Pan,Wang, Jian-Wei,Zhang, Wen-Hua,Bai, Hongzhen,Tang, Guping,Young, David J.
, p. 2993 - 3000 (2021/08/23)
Nanoformulations of mononuclear Pt complexes cis-PtCl2(PPh3)2 (1), [Pt(PPh3)2(L?Cys)] ? H2O (3, L?Cys=L-cysteinate), trans-PtCl2(PPh2PhNMe2)2 (4;
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.
, (2021/07/13)
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.
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.
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 (2020/11/02)
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.
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 (2016/01/15)
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.
An investigation of the mixed-bridge dinuclear complex [Pt 2(μ-S)(μ-NH2)(PPh3)4] +
Henderson, William,Oliver, Allen G.
, p. 49 - 56 (2014/05/06)
The product formed by reaction of cis-[PtCl2(PPh 3)2], NH3 and Na2S in ethanol, previously reported as [Pt2(μ-S)(PPh3)4], has been reinvestigated by electrospray ionisation mass spectrometry (ESI MS) and found to consist of the ethanol solvate of the well-known metalloligand [Pt2(μ-S)2(PPh3)4] together with the novel mixed-ligand complex [Pt2(μ-S)(μ-NH 2)(PPh3)4]+. Upon prolonged ageing in air, a mixture of this complex with [Pt2(μ-S)(μ-O)(PPh 3)4 + H]+ is observed by ESI MS. [Pt 2(μ-S)(μ-NH2)(PPh3)4] + can be prepared from cis-[PtCl2(PPh3) 2] and aqueous NH3 using a stoichiometric quantity of sodium sulfide, or by reaction of [Pt2(μ-S)2(PPh 3)4] with 2-chloro-1-methylpyridinium tetraphenylborate and ammonia; the complex was structurally characterised as its tetraphenylborate salt. This novel desulfurisation reaction was serendipitously discovered during investigations on the reactivity of [Pt2(μ-S) 2(PPh3)4] towards 2-chloro-1-methylpyridinium iodide giving the known iodo complex [Pt2(μ-S)(μ-I)(PPh 3)4]+, isolated as either the PF 6- or I- salts.
Trans-cis isomerization of [(C6H5)3P]2PtCl2 complex in dimethylformamide solutions
Jacewicz, Dagmara,Pranczk, Joanna,Wyrzykowski, Dariusz,?amoj?, Krzysztof,Chmurzyński, Lech
, p. 620 - 624 (2015/02/19)
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.
Isomerization of platinum-coordinated iminoethers induced by spectator ligands: Stabilization of the Z anti configuration
Giardina-Papa, Daniela,Intini, Francesco P.,Pacifico, Concetta,Natile, Giovanni
, p. 13058 - 13067 (2013/12/04)
Iminoether derivatives of the formula trans-[PtCl2{HN=C(R) OR′}2] proved to be endowed with remarkable antitumor activity in vivo. Moreover, these trans compounds were more cytotoxic than their cis congeners, a trend opposite to that generally observed for corresponding platinum complexes with ammines. The imino ligands can have either E or Z configuration about the C=N double bond, and in the case of R = R′ = Me, the E configuration is by far thermodynamically preferred. However, substitution of chloride anions with neutral ligands (L) alters the relative stability of the E and Z isomers. Upon investigation of the derivatives with L = PPh 3, AsPh3, Me2S=O, and (H2N) 2C=S, it has been concluded that an electrostatic interaction between the oxygen lone pair of the iminoether and the platinum center, fostered by the net positive charge of the complex and the low dielectric constant around the metal core provided by the hydrophobic L ligands, stabilizes the Z configuration. The same factors can favor iminoether isomerization. These conclusions are fully supported by X-ray crystal data. In the case of a reaction with thiourea, an aminic group of thiourea can substitute the methoxy group of a cis-iminoether, leading to the formation of a cyclic compound in a process reminiscent of the McLafferty rearrangement. Such a rearrangement could play a role in the interaction of the platinum-iminoether compounds with target DNA and proteins.
Diplatinum complexes: Chemoselective reactions of the μ-orthometalated, metal-metal bonded complex
Archambault, Christine,Bender, Robert,Dusausoy, Yves,Welter, Richard,Braunstein, Pierre
, p. 545 - 552 (2013/06/26)
In order to investigate further the chemoselectivity of reactions involving the μ-orthometalated, metal-metal bonded dinuclear Pt(I) complex [Pt 2(μ-o-C6H4PPh2)(μ-PPh 2)(PPh3)2](Pt-Pt) (1), it was reacted with HCl and HI using various stoichiometries. The first step was the breaking of the metal-carbon bond and the formation of C-H and Pt-X bonds. When a 1:1 ratio was used, the complexes [Pt2X(μ-PPh2)(PPh3) 3](Pt-Pt) (2, X = Cl; 3, X = I) have been obtained but the use of a 2:1 ratio resulted instead in the formation of the complexes [Pt 2(μ-H)(μ-PPh2)X2(PPh3) 2](Pt-Pt) (4, X = Cl; 6, X = I). The latter transformed into [Pt 2(μ-X)(μ-PPh2)X2(PPh3) 2] (5, X = Cl; 7, X = I) in the presence of an additional equivalent of HX. The cis,cis- and cis,trans-isomers of 7 were also obtained by oxidation of 3 with one equivalent of iodine. Whereas compounds 4, cis,cis-5, and cis,trans-7 have been characterized in solution, the complexes 2·1/2C7H8, 3, 6 and cis,cis-7 have been isolated and structurally characterized by X-ray diffraction.
Diverse C-C bond-forming reactions of bis(carbene)platinum(II) complexes
Klet, Rachel C.,Labinger, Jay A.,Bercaw, John E.
, p. 6652 - 6657 (2012/11/07)
The platinum(0) complex Pt(PPh3)4 catalyzes coupling of the carbene ligands of (CO)5Cr{C(OMe)(p-MeOC6H 4)} (1). The stable bis(carbene)platinum(II) complexes Cl 2Pt{C(OMe)(Me)}2
