************OWARI COMPLEX SEMINAR LXVI*************

Title：Supercritical carbon dioxide as an alternative solvent for Green Chemistry: key questions and issues regarding solubility.

Speaker：Manuel F. Ruiz-Lopez

Affiliation：Universite de Lorraine

Date：Tue. Jan 12th, 1:30 pm (Almost one hour)

Place：4th Lecture Room (1F)
Graduate School of Information Science

Abstract： In pharmaceutical and other industrial applications, the most commonly employed solvents are volatile organic compounds, which display important atmospheric, environmental and health issues. In the last decades, however, great efforts have been made to provide alternative “green” solvents and to develop new chemical routes using them. In this context, the technology of supercritical fluids has appeared as one of the most appealing choices. Supercritical fluids are such to provide intermediate densities between liquids and gases as well as smooth variations of physical properties with density changes.

Among the most used supercritical solvents, carbon dioxide (scCO2) plays an eminent role. It is naturally abundant and cheap, nontoxic, relatively inert and the supercritical conditions are easy to achieve (Tc = 31.1°C, Pc = 7.4 MPa). Unfortunately, due to the low polarity of this medium, compounds such as polar organic and organometallic molecules and high molecular mass systems are poorly soluble. This fact has motivated a strong interest in developing tools for increasing the solubility power of scCO2 and extensive work has been reported following two main research directions: the use of co-solvents and the development of  “solubilizers”, which can be seen as CO2-soluble surfactants with emulsifying or dispersion properties that transport insoluble substances into the solvent.

In this seminar, I will present our recent research in this field, which includes: 1) the understanding of the CO2-philic concept based on the use of computational models and the analysis of electronic structure calculations, and 2) the study of cyclodextrin solubilizers and the driving forces that control supramolecular encapsulation in this medium through a combined experimental and theoretical approach.

**************************************************