H.S. Randhawa

Thermal Studies of Metal Complexes Formed in Ag(I)-, Cd(II)-, UO2(II)-, VO(II), Co(II)- and Hg(II)-sulphamethoxazole Systems

The mechanism of thermal decomposition of the metal complexes of sulphamethoxazole (SMZ) viz: [Ag(SMZ)H2O], [Cd(SMZ)2(H2O)2], [VO(SMZ)2(H2O)2], [UO2(SMZ)2]H 2O, [Hg(SMZ)2(H2O)2] and [Co(SMZ)2(H2O)2]H2O has been accomplished on the basis of TG, DTG and DTA studies. The mechanism of thermal decomposition of these complexes conforms to the stoichiometry of the complexes based on elemental analysis.

Energetics of n-π* and π-π* charge-transfer complexes formed between amine donors and chloranil as π-electron acceptor

The heats of formation ofn-π* andπ-π* charge-transfer interactions have been computed from the charge-transfer spectra of molecular complexes formed in the pyridinechloranil and aniline-chloranil systems.ZusammenfassungAnhand der Charge-Transfer-Spektren von Molekülkomplexen aus Pyridin-Chloranil und Anilin-Chloranil wurde die Wärme für die Bildung vonn-π* und π-π* Charge-Transfer-Wechselwirkungen berechnet.

Stoicmometry, thermodynamic functions and stability of some charge transfer complexes

Abstract The stoichiometry of charge transfer complexes formed between Schiff base donors and aromatic hydrocarbon acceptors was established by solid-liquid phase equilibrium diagram studies. The thermodynamic functions of some stable charge transfer complexes were determined by differential scanning calorimetry and the area under the curve of the congruent compound is fixed as the criterion to predict the relative strength of charge transfer complexes on the basis of thermodynamic parameters.

Stoichiometry and stability of some solid state charge transfer complexes formed in imidazole-hydrocarbon systems

Abstract The compositions of charge transfer complexes of imidazole with some aromatic hydrocarbons (naphthalene, anthracene, phenanthrene and biphenyl) were established through phase diagram studies. The enthalpies and entropies of fusion of these complexes were estimated by differential scanning calorimetry. The relative stabilities of the solid state charge transfer complexes in the donor-acceptor systems studied could not be predicted from the areas under the curves of the congruent compounds in the phase diagrams.

On the compositions and strengths of charge-transfer complexes

The compositions of charge-transfer complexes of urea and thiourea with some aromatic hydrocarbons (naphthalene, anthracene, phenanthrene and biphenyl) have been established through phase diagram studies. The enthalpies and entropies of fusion of these complexes have been estimated by differential scanning calorimetry. It is observed that the relative stabilities of the solid-state charge-transfer complexes in the donor-acceptor systems studied cannot be predicted from the areas under the curves of the congruent compounds in the phase diagrams.ZusammenfassungDie Zusammensetzung von Donator-Akzeptor-Komplexen von Harnstoff und Thioharnstoff mit einigen aromatischen Kohlenwasserstoffen, nämlich Naphthalin, Anthracen, Phenanthren und Biphenyl, wurde durch Phasendiagrammuntersuchungen ermittelt. Schmelzenthalpie und -entropie dieser Komplexe wurden mittels DSC bestimmt. Es wurde festgestellt, daß die relative Stabilität der festen Donator-Akzeptor-Komplexe nicht aus der Fläche unter der Kurve im Phasendiagramm der kongruenten Verbindungen vorausgesagt werden kann.РезюмеНа основе фазовых диа грамм установлен сос тав комплексов с перенос ом заряда (КПЗ) мочевины и тиомоч евины с такими аромат ическими углеводородами, как н афталин, антрацен, фенантрен и бифенил. С помощью ДСК установлена энтальп ия и энтропия плавлен ия этих комплексов. Пока зано, что относительн ая устойчивость твердо тельных КПЗ в изученн ых донороно-акцепторны х системах не может бы ть установлена, исходя и з площади под кривой н а фазовой диаграмме ко нгруэнтных соединен ий.