Interaction of methyltin(IV) compounds with carboxylate ligands. Part 2: formation thermodynamic parameters, predictive relationships and sequestering ability

Abstract

Thermodynamic data of mono-, di-and tri-methyltin(IV)-carboxylate complexes (acetate, malonate, succinate, oxydiacetate, diethylenetrioxydiacetate, malate, citrate, 1,2,3-tricarballylate, 1,2,3,4-butanetetracarboxylate, 1,2,3,4,5,6-benzenehexacarboxylate) in aqueous solution are reported at t = 25• C and I = 0 mol l −1 . Thermodynamic parameters obtained were analysed to formulate empirical predictive relationships as a function of different parameters, such as the number of carboxylate groups of the ligand and the charge of the alkyltin(IV) cation. Sequestration diagrams of citrate and 1,2,3-tricarballylate towards alkyltin(IV) cations at different pH values are also reported and discussed.

Sequestration of Alkyltin(IV) Compounds in Aqueous Solution: Formation, Stability, and Empirical Relationships for the Binding of Dimethyltin(IV) Cation by N‐ and O‐Donor Ligands

“…From the analysis of Tables 2 and 3 , some systematic differences and regularities emerged in the stability of various dmt /amine and dmt /aminoacid species, suggesting the opportunity to find some useful relationships for the modeling of their behavior. This possibility is also supported by previous studies on the stability of various organotin/ligand systems, where several empirical relationships were found and used with predictive purposes (see, e.g., [ 16 , 18 , 19 ]). For example, the stability of some diethyltin(IV)/ligand species can be expressed as a function of the number of amino- and/or carboxylic groups in the ligand(s) involved in the formation reaction of these species [ 16 ].…”

“…This is particularly relevant in the study of organotin(IV) speciation in natural and waste waters and biological fluids, where other metals and various organic (carboxylic and aminic in particular) and inorganic ligands could be simultaneously present in different concentrations (see, e.g., in [8, 14–18]). In fact, it is well known that organotin(IV) compounds show different biological and environmental activity depending on their speciation: the formation of different species plays an important role in organotin(IV) toxicity and exposure to living organisms and influences their availability, their accumulation, biomodification, and their transport inside the organisms and within and between various environmental compartments [8, 9, 11, 15, 18, 19]. …”

“…For example, in some of our previous papers we derived some empirical relationships for the modeling of the stability of diethyltin(IV) complexes with O- and N-donor ligands [ 16 ], whilst in others we modeled that of mono-, di-, and trialkyltin(IV) complexes with various carboxylic ligands as a function of simple ligand and metal structural parameters (e.g., the charge of the alkyltin(IV) cation, the number and nature of binding sites, etc.) [ 19 ].…”

COORDINATION COMPOUNDS Sn (IV) WITH HYDROXYCARBOXYLIC ACIDS

“…Потенциометрически исследовано взаимодействие монометилтрихлорида олова с лимонной кислотой [32] В результате авторам [35,36] удалось получить сравнительную характеристику стабильности координационных оловоорганических соединений с карбоксилатными лигандами в зависимости от числа протонированных и депротонированных карбоксильных групп, гидроксогрупп, присутствующих в молекулах лигандов, а также от заряда катиона алкилолова (IV).…”

“…1).Авторы[35] продолжили исследования в данном направлении. Свою следующую статью[36] они посвятили калориметрическому определению термодинамических параметров (∆G o , ∆H o и T∆S) исследованных систем, в частности CH 3 SnCl 3 , (CH 3 ) 2 SnCl 2 , (CH 3 ) 3 SnCl -яблочная(лимонная) кислоты -вода. Были предложены равновесия, существующие в этих системах, и проведена их оценка с использованием специальных компьютерных программ.…”