Hydrogen bonding-mediated self-assembly of rigid and planar metallocyclophanes and their recognition for mono- and disaccharides

A hydrogen bonding approach has been developed to facilitate the self-assembly of a new series of rigid and planar metallocyclophanes. Two new anthranilamide derivatives 1 and 2, which are incorporated with two acetylene units, respectively, have been synthesized and characterized. X-ray analysis (for 1), 1D and 2D H-1 NMR and IR experiments reveal that, due to the formation of intramolecular three-centered hydrogen bonding, both compounds adopt rigid and planar conformations with the two acetylene units located at the same side of the anthranilamide skeleton. Two new metallocyclophanes 17 and 18 have been constructed in moderate yields from the reaction of 1 and 2 with trans-Pt(PEt3)(2)Cl-2, respectively, in dichloromethane in the presence of diethylamine and cupric chloride. Fluorescent and H-1 NMR investigations reveal that both 17 and 18 can efficiently complex mono- and disaccharide derivatives in chloroform, with a binding selectivity for disaccharides, which is driven by intermolecular hydrogen bonding. (C) 2004 Elsevier Ltd. All rights reserved.