97101-54-7Relevant academic research and scientific papers
A kinetic and mechanistic study of analogous bifunctional dialkylamine platinum(ii) complexes
Olusegun, Moses Ariyo,Reddy, Desigan,Jaganyi, Deogratius
, p. 5138 - 5146 (2020)
This study was aimed at investigating the comparative substitution behaviour of analogous cis/trans-Pt(ii) complexes with inert dialkylamine ligands. The rate of substitution of the aqua ligands by three nucleophiles, viz. thiourea (TU), 1,3-dimethylthiourea (DMTU) and 1,1,3,3-tetramethylthiourea (TMTU), for the complexes: [cis-Pt(OH2)2(NH3)2](ClO4)2 (cPt), [cis-Pt(OH2)2(NH2CH3)2](ClO4)2 (cPtM), [cis-Pt(OH2)2{NH2CH(CH3)2}2](ClO4)2 (cPtR), [trans-Pt(OH2)2(NH3)2](ClO4)2 (tPt), [trans-Pt(OH2)2(NH2CH3)2](ClO4)2 (tPtM) and [trans-Pt(OH2)2{NH2CH(CH3)2}2](ClO4)2 (tPtR) was investigated under pseudo first-order conditions as a function of concentration and temperature by stopped-flow and UV/visible spectrophotometry. The reactions of the cis-complexes proceed in two concerted steps whereas those of the trans-complexes followed a stepwise mechanism involving rate determining substitution of the first chloride followed by a fast second substitution step, with no intermediates being detected. The pseudo first-order rate constants, kobs obeyed the rate law: kobs = k2[nucleophile]. The trans-complexes were observed to be approximately 103 times more reactive than their corresponding cis-analogues. The electronic and the steric hindrance due to the geometries of the complexes controlled the overall reaction pattern. The order of reactivity of the complexes is tPt > tPtM > tPtR > cPt > cPtM > cPtR. The reactivity of the nucleophiles with the complexes decreases with an increase in steric demand in the order: TU > DMTU > TMTU. The trans-dialkylamine complexes formed distinctly different kinetic products relative to their cis-analogues. 195Pt NMR spectroscopic results confirmed the final kinetic products of each of the cis- and trans-complexes. The negative entropy of activation (ΔS≠) values in all the complexes investigated assert an associative substitution mechanism, with the mechanism being more pronounced in the cis-complexes than in their trans-analogues.
Versatile Route to trans-Platinum(II) Complexes via Manipulation of a Coordinated 3-(Pyridin-3-yl)propanoic Acid Ligand
Cabrera, Silvia,Navas, Francisco,Matesanz, Ana I.,Maroto, Marta,Riedel, Tina,Dyson, Paul J.,Quiroga, Adoracion G.
, p. 7200 - 7208 (2019/05/01)
We describe the direct coupling of alcohols and amines to a 3-(pyridin-3-yl)propanoic acid ligand coordinated to a Pt(II) to afford ester and amide derivatives. Using this approach, a family of trans-Pt(II) compounds with amine ligands bearing long perfluorinated chains was prepared, as these chains potentially endow the complexes with thermoactivatable properties. Related compounds with alkyl chains in place of the perfluorinated chains were also prepared as controls using the same direct coupling method. The stability of the complexes in solution, their reactivity with DNA and proteins, and their antiproliferative activity evaluated in tumorigenic (A2780 and A2780cisR) and nontumorigenic (HEK293) cells at 37 °C and following exposure to elevated temperatures (that mimic the temperatures employed in thermotherapy) were also studied to assess their utility as putative (thermoactivated) anticancer agents.
Molecular interaction fields vs. quantum-mechanical-based descriptors in the modelling of lipophilicity of platinum(iv) complexes
Ermondi, Giuseppe,Caron, Giulia,Ravera, Mauro,Gabano, Elisabetta,Bianco, Sabrina,Platts, James A.,Osella, Domenico
supporting information, p. 3482 - 3489 (2013/03/28)
We report QSAR calculations using VolSurf descriptors to model the lipophilicity of 53 Pt(iv) complexes with a diverse range of axial and equatorial ligands. Lipophilicity is measured using an efficient HPLC method. Previous models based on a subset of these data are shown to be inadequate, due to incompatibility of whole molecule descriptors between carboxylato and hydroxido ligands. Instead, the interaction surfaces of complexes with various probes are used as independent descriptors. Partial least squares modelling using three latent variables results in an accurate (R2 = 0.92) and robust model (Q2 = 0.87) of lipophilicity, that moreover highlights the importance of size and hydrophobicity terms and the modest relevance of hydrogen bonding.
A long-lived ascorbate radical in the platinum(II) catalysed reductions of platinum(IV) antitumor drugs
Bose, Rathinda N.,Weaver, Evelyne L.
, p. 1797 - 1800 (2007/10/03)
A ling-lived ascorbate radical was characterized during the reduction of a series of platinum(IV) drugs; ascorbate reductions proceed through a platinum(IV)-ascorbate intermediate, the formation of which is catalysed by platinum(II).
SYNTHESIS OF (GLYCOLATO-O,O')DIAMMINEPLATINUM(II) AND ITS RELATED COMPLEXES
Totani, Tetsushi,Aono, Katsutoshi,Komura, Michihiro,Adachi, Yasuko
, p. 429 - 432 (2007/10/02)
Glycolatoplatinum(II) complexes, , having a novel five-membered ring structure were obtained by adding an equimolar quantity of glycolic acid to cis- (L: NH3, amines) in water followed by heating.These complexes have also been obtained by reaction of cis- with sodium glycolate in neutral aqueous solution.These complexes have been characterized by SIMS, IR, and NMR spectroscopy.
Kinetics of the Displacement of Chloroacetate Ion from cis-Bis(chloroacetato)-bis(isopropylamine)platinum(II) and the (Chloroacetato)(1,5-diamino-3-azapentane)platinum(II) Cation
Canovese, Luciano,Tobe, Martin L.,Annibale, Giuliano,Cattalini, lucio
, p. 1107 - 1114 (2007/10/02)
The displacement of ClCH2CO2- from cis-iNH2)2(ClCH2CO2)2> and + (dien=1,5-diamino-3-azapentane) by solvent, Cl-, Br-, and SCN- has been studied in aqueous solution at 25.0 deg C.The reactions are catalysed by acid by way of a pre-equilibrium protonation of the carboxylate ligand.In the absence of added acid the cationic monocarboxylato complex exhibits a normal nucleophilic discrimination power, comparable to that of the corresponding chloro complex and the nucleophile-independent pathway makes only a small contribution to the consumption of the substrate.In the uncatalysed reactions of the bis(carboxylato) complex, the nucleophile-independent pathway dominates the substitution by the weak nucleophile, Cl-, and a relatively strong nucleophile, such as SCN-, is required to make the direct substitution pathway important.The unusually large contribution from the nucleophile-independent pathway is discussed.
Effects of Geometric Configuration and Steric Hindrance on Rates and Mechanisms of Oxidation of Diaminedichloroplatinum(II) Complexes by Tetrachloroaurate(III) Ions
Peloso, Arnaldo
, p. 1285 - 1290 (2007/10/02)
The oxidation reactions of trans- and/or cis- by - in the presence of Cl have been kinetically investigated in acetonitrile (R=H,Me,Et,Prn,Pri,Bun,Bui,Bus,But,CH2But,CH2Ph, or cyclo-C6H11).The rate law for the oxidation of the trans complexes consists mainly of a third-order rate term, kc->->, whereas an additiona rate term, ka->->/(1+kb->), operates in the case of the cis complexes.A reaction scheme is proposed.The oxidation rates of both cis and trans complexes appear to be reduced by increasing the steric hindrance of the amine, cis complexes being more sensitive towards changes of steric hindrance than trans analogues.Approximate linear relationships correlate the reactivities (log k) of both cis and trans complexes with an amine steric hindrance parameter.
