97101-54-7Relevant articles and documents
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.
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.
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.
