Infrared Spectra of 2,9-Dimethyl-1,10-phenanthroline, Its Hydrates and Acid Perchlorate

Abstract

Infrared absorption spectra of 2,9-dimethyl-1,10-phenanthroline (dmp), dmp 0.5H₂O, dmp 2H₂O, and dmp HClO₄ have been obtained over the range 4000-650 cm^-1. Bands between 1610 and 1545 cm^-1 are attributed to stretching vibrations within the phenanthroline ring system. The in-phase out-of-plane motion of the ring hydrogen atoms is associated with intense absorption at 845 cm^-1. A strong band is observed at 728 cm^-1 which cannot be accounted for in terms of an out-of-plane CH deformation. The perchlorate is characterized by shifts of the strongest absorption bands observed in the spectra of dmp and the hydrates.