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Updated: Jun 27, 2025
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Molecular structure and selective theophylline complexation by conformational change of diethyl
Juan Saulo González-González1, Alfonso Martínez-Santos1, María José Emparán-Legaspi2
1Instituto de Farmacobiología, Universidad de la Cañada, Carretera Teotitlán-San Antonio Nanahuatipán, km 1.7 s/n, Teotitlán de Flores Magón, Oaxaca 68540, Mexico.
Abstract:
The receptor ability of diethyl N,N'-(1,3-phenylene)dicarbamate (1) to form host-guest complexes with theophylline (TEO) and caffeine (CAF) by mechanochemistry was evaluated. The formation of the 1-TEO complex (C12H16N2O4·C7H8N4O2) was preferred and involves the conformational change of one of the ethyl carbamate groups of 1 from the endo conformation to the exo conformation to allow the formation of intermolecular interactions. The formation of an N-H...O=C hydrogen bond between 1 and TEO triggers the conformational change of 1. CAF molecules are unable to form an N-H...O=C hydrogen bond with 1, making the conformational change and, therefore, the formation of the complex impossible. Conformational change and selective binding were monitored by IR spectroscopy, solid-state 13C nuclear magnetic resonance and single-crystal X-ray diffraction. The 1-TEO complex was characterized by IR spectroscopy, solid-state 13C nuclear magnetic resonance, powder X-ray diffraction and single-crystal X-ray diffraction.
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