Betha-Cyclodextrin and Azobencene Complexes Evaluated by NMR. Towards Photomodulable Biomimetic Systems

ZULMA QUIROLO; JOSE MARTINS; VERONICA DODERO

Bahia Blanca

Congreso; - IV Congreso Argentino de Materia Blanda - (mab IV ); 2012

Universidad Nacional del Sur

BETHA CYCLODEXTRIN AND AZOBENZENE COMPLEXES EVALUATED BY NMR. TOWARDS PHOTOMODULABLE BIOMIMETIC SYSTEMS Z.B. QUIROLO (1), J.C. MARTINS (1) and V.D. DODERO (1) (1) INQUISUR- (UNS. - CONICET) - Bahía Blanca - Argentine. (2) Organic Chemistry Department - Ghent University - Ghent - Belgium. zulma.quirolo@uns.edu.ar A molecular machine is defined as an assembly of a distinct number of molecular components designed to perform machine-like movements in response to an appropriate external stimulus (Harada, A. 2001). In biological systems, there are many molecular and/or supramolecular machines, such as enzymes, antibodies, and viruses. In this context, we are interested in the design of a two point switches capable of photoswitch the transcriptional process (Alberts et al., 1994) in a non-covalent fashion. As host-guest couple we have chosen Cyclodextrins (CyD) and different azobenzene molecules (Fig.1 and 2) Cyclodextrins are cyclic oligosaccharides composed of 6, 7 or 8, alfa-1,4-linked glucose residues and characterized by a truncated cone shape. In their cavity, the cyclodextrins can accommodate a wide class of organic molecules leading to inclusion complexes with various stoichiometries. (Dodziuk, H. 2006). Various methods have been used for host-guest complex study, such UV, IR, HPLC, DSC, NMR, etc. NMR spectroscopy is one of the most important and remarkable methods for chemical structures and has been widely used. Chemical shift changes in the H1 NMR spectra have been used to monitor de complex formation process and especially three-dimensional geometry information. Herein we present the complex formation of a series of azo molecules with different functionalities as ligands for the beta-Cyclodextrin (beta-CyD) by NMR.