Structural Chemistry & Crystallography Communication

Unusual molecular movements in the solid state

International Conference on Applied Crystallography
October 16-17, 2017 | Chicago, USA

Vittal Jagadese J

National University of Singapore, Singapore

Posters & Accepted Abstracts: Struct Chem Crystallogr Commun

DOI: 10.21767/2470-9905-C1-003

Abstract

Crystallization is a kinetic process and the experimental conditions like solvents, concentration, pH, temperature and time have greater control on the nature of products in the synthesis of coordination network structures. During crystallization, the ligands bind to the metal ions reversibly and hence, the least soluble polymer will crystallize first, independent of the metal-ligand ratio used in the crystallization. In the kinetic products, quite often the solvents are bonded to the metal ions. The removal of these coordinated solvents is likely to transform the kinetically formed coordination polymers (CPs) into thermodynamically stable products. Such structural transformations have been demonstrated in many coordination polymeric network structures, if the solid state structure of the products can be determined unequivocally. If the structural transformation to thermodynamic product is accompanied by the parallel alignment of double bonds, then the photochemical reactivity could be tested through the formation of cyclobutane rings from [2+2] cycloaddition reactions. Such techniques have been successfully used to predict the structural transformation of linear CPs to photoreactive ladder structures due to desolvation. In his laboratory the speaker has encountered a number of such molecular movements in the solid state which will be highlighted in this talk.