Polymer-surfactant mixed systems have attracted much attention due to their importance from the academic as well as applied point of view. Therefore, to evaluate the thermodynamic properties of polymer-surfactant self-assembled system, the critical micelle concentration (CMC) of CTAB and CTAB/PEO mixture was determined at different CTAB/PEO ratios and various molecular masses of PEO by employing surface tensiometric, conductometric, and light scattering techniques. The CMC of CTAB was increased as the concentration and molecular mass of the polymer increased. Using surface tensiometry, the thermodynamics of adsorption, surface excess concentration and the minimum area occupied by surfactant molecules for different surfactant-polymer mixtures were also evaluated. CMC, area per molecule, free energy of micellization and degree of counter ion binding were also determined. It was found that most of these parameters increased as the concentration of polymer increased, whereas the surface excess concentration was found to decrease by increasing the polymer ration in the mixed system. The hydrodynamic radius (Rh) of the micelle particles calculated from dynamic light scattering technique showed a similar trend. Most of the results from different techniques support each others.

Seis novos ésteres diorganoestanho(IV) com composição geral R2SnL2 (onde R: Me(1), Et(2), Pr(3), Bu(4), Ph(5), Bz(6) e L(7): ácido p-N-maleimidobenzóico) foram sintetizados neste trabalho. Espectros de absorção no infravermelho e de Mössbauer de 119mSn no estado sólido revelaram o comportamento bidentado de L em relação ao centro diorganoestanho(IV) nos complexos octaédricos distorcidos. Espectros de RMN de ¹H, 13C e 119Sn, em CDCl3, indicaram hexacoordenação em 1-4, pentacoordenação de 5 em geometria trapezoidal distorcida, e ausência de hipercoordenação no arranjo tetraédrico em 6. Dados de análise elementar comprovaram a estequiometria dos compostos organoestanho(IV). Foram realizados testes in vitro contra cinco espécies de Leishmania: L. major, L. tropica, L. infantum, L. mex. mex. e L. donovani. Resultados promissores foram observados e, com base nos dados obtidos nesses ensaios, tentou-se estabelecer relações estrutura-atividade. O aumento no tamanho dos grupos R em {R2SnIV}2+ aumentou a lipofilicidade dos complexos organoestanho(IV), acentuando assim a atividade antileishmania.

Six new diorganotin(IV) esters with the general composition R2SnL2 (where R: Me(1), Et(2), Pr(3), Bu(4), Ph(5), Bz(6) and L(7): p-N-maleimido-benzoic acid) have been synthesized. Solid state FTIR and 119mSn Mössbauer spectra revealed bidentate behavior of L towards the diorganotin(IV) centre in the distorted octahedral products. ¹H, 13C and 119Sn NMR spectra in CDCl3 indicated hexacoordination in 1-4, penta-coordination of 5 in skew-trapezoidal geometry, and absence of hypercoordination in tetrahedral 6. Elemental analyses data have been found to corroborate the stoichiometry of the title organotin(IV) compounds. In vitro anti-leishmanial screenings have been conducted on five leishmanial strains of L. major, L. tropica, L. infantum, L. mex. mex. and L. donovani. Promising results have been observed and, on the basis of the data obtained during these assays, a structure-activity relationship has been suggested. The increasing size of the R groups in the {R2SnIV}2+ moieties increased the lipophilicity of organotin(IV) complexes, which thereby enhanced the anti-leishmanial activity.

Uma série de complexos di- e tri-organoestanho(IV) de metilglutarato foram sintetizados e caracterizados por espectroscopia de RMN de ¹H, 13C e 119Sn, no infravermelho e Mössbauer de 119Sn. Baseado nestas técnicas propõe-se que o ligante se encontra ligado ao estanho através do oxigênio da carbonila. Os dados revelam também que os complexos diorganoestanho(IV) são hexacoordenados, com geometria octaedrica, enquanto que os complexos triorganoestanho(IV) são pentacoordenados e possuem geometria bipiramidal trigonal. A avaliação biológica contra vários microorganismos indica que os complexos diorganoestanho(IV) são menos ativos que os triorganoestanho(IV).

A series of di and triorganotin(IV) complexes of monomethyl glutarate have been synthesized and characterized through ¹H 13C 119Sn NMR, FT-IR and 119Sn Mössbauer spectroscopy. On the basis of these techniques, it is proposed that the ligand molecule is bound to the tin atom through the carbonyl oxygen. The data reveal that diorganotin(IV) complexes exhibit hexa-coordination with octahedral geometry, while triorganotin(IV) complexes have penta-coordination with trigonal bipyramidal geometry. Biological evaluation against various microorganisms indicate that diorganotin(IV) complexes are less active than the triorganotin(IV) complexes.