Abstract
Triamterene (TM) is an important diuretic medication used to treat edema caused by various conditions, including liver and heart disease. Triamterene is a good donating drug containing seven nitrogen atoms, out of which three are found as -NH2 terminal groups and the other four atoms are involved in aromatic rings as 6-phenylpteridine moiety. This study focused on the spectroscopic investigation of electron transfer associated with the reaction between TM pure drug and two different types of electron acceptors, namely iodine, a sigma-acceptor, and 7,7,8,8-tetracyanoquinodimethane (TCNQ), a pi-acceptor. The morphological features of the associated charge-transfer (CT) complexes were examined using scanning and transmission electron microscopy. The spectroscopic characteristics of the CT complexes in both solid and solution states were examined using UV-visible (UV/Vis), Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (H-1-NMR) spectroscopy and elemental analyses. FTIR bands were interpreted and confirmed that the interaction between TM and iodine or TCNQ acceptors occurs through the electron lone pair on the nitrogen atom of the -NH2 group and the benzene ring of the donor to the acceptor molecule with donor: acceptor molar ratio of 1:2.