Physico-chemical study of complexation of silver ion (Ag+) by macrocyclic molecules (hexa-Helicenes) based on statistical physics theory: new description of a cancer drug

Abstract

In recent papers, it is found that the silver-[6]Helicene complex can be used as a cancer drug but the interaction silver-hexaHelicene has not yet proven. the idea of this paper is to investigate the complexation process of the [6]Helicene by the silver metal (Ag +) using three types of adsorbates. Indeed, the adsorption of silver chloride, silver nitrate and silver sulfide into the sensor films deposited on the QCM electrode are measured at three temperatures (293-333 K). Films of the [6]Helicene were deposited on the QcM resonators using spin coating method in order to obtain uniform and homogenous sensor surface. Experimental results indicated that the [6]Helicene can form a stable complex with the silver ion and that the Agcl is the appropriate adsorbate for the complexation achievement. Actually, an advanced modeling analysis by means of statistical physics adsorption models is applied to explore the new vision of the complextion system. the values of the models parameters are deduced from fitting the experimental data with the developed models. They result in confirming the experimental findings by comparing the complexation energies of the three examined systems. in particular, for the silver nitrate, the Van-der-Waals parameters explained the isotherms drop at high concentration through the lateral interactions between the adsorbates. the adsorption energies analysis showed the highest interaction AgCl-[6]Helicene. Density functional theory (DFT) simulations showed that chemical bonds take place during the adsorption of silver chloride on hexaHelicene which confirms that the [6]Helicene can function as a chiral molecular tweezer of the univalent cationic silver.

Calculation of adsorption isotherms by statistical physics models: a review

“…Van der Waals parameters are integrated into advanced statistical physics models to take into account the lateral interactions between particles of adsorbate when they are treated as a real gas (Yahia and Manel 2020a). These parameters can give a good explanation for the decrease in the adsorbed amount after saturation (Yahia and Manel 2020b). Increasing the value of cohesion pressure "a" signifies that the adsorbate-adsorbate interaction increases, which minimizes the attractive forces between the adsorption sites and the adsorbate species.…”

“…Ben Yahia et al (2020b) studied the interaction between the silver ion (Ag + ) under three forms, silver chloride, silver nitrate and silver sulfide, with hexahelicene at three temperature through the adsorption isotherms determined using the quartz crystal microbalance (QCM). The isotherms obtained for the three adsorbates showed different behaviors, indicating that the isotherm profile was influenced by the nature of the adsorbate in contact with the surface of the hexahelicene.…”

Study of interaction of metal ions with methylthymol blue by chemometrics and quantum chemical calculations

“…Methods originated from the quantum chemical such as density functional theory (DFT) and its time-dependent form (TD-DFT) have appeared as reliable methodologies in computational chemistry 27 , 28 . The DFT approaches have widely been used to study different aspects of chemical studies, such as investigating electronic structures and reaction mechanisms of some small molecules 29 , 30 , adsorption properties of surface reactions 31 and reaction mechanism of complicated enzymatic systems 32 . In addition, there is a large number of previous studies that used TD-DFT calculations to predict electronic transitions and to establish a correlation between the experimental and computed wavelengths 33 – 38 .…”

Ab initio adiabatic study of the AgH system

“…The silver hydride AgH molecule has been the subject of several experimental 5 – 11 and theoretical 4 , 12 – 25 works. There is four experimental studies have been examined by Le Roy et al 5 , Seto et al 6 , Rolf-Dieter et al 7 and Helmut et al 8 .…”