Configurations of benzene and pyridine molecules adsorbed on graphitic surface of microporous carbon

The possible configurations of benzene and pyridine molecules adsorbed in m icroporous carbon were analyzed by synchrotron radiation-excited soft X-ray emission spectroscopy and by analyzing its spectral features using DV-XQ m olecular orbital calculations. The distances between the adsorbed molecules and the graphitic surface were estimated to be approximately 0.33 nm in bo th benzene- and pyridine-adsorbed systems. Both molecular orientations were also estimated to be almost parallel to the graphitic surface of microporo us carbon. The electronic states of benzene and pyridine molecules adsorbed on the graphitic surface were similar to those of individual nonadsorbed f ree molecules. Therefore, the adsorption of benzene and pyridine molecules in the microporous carbon can be confirmed to be physisorption, and there i s little charge-transfer between the adsorbed molecules and the graphitic s urface.