Characterization of charge-transfer complex formation between 3, 6-diamino-9<i>H</i>-carbazole and 3,6-dinitro-9<i>H</i>-carbazole

271-276Electron donor-acceptor (EDA) interaction between 3,6-diamino-9H-carbazole (DAC) as the donor, and 3,6-dinitro-9H-carbazole (DNC) as the acceptor, has been characterized from IR spectral, differential scanning calorimetric (DSC), and X-ray diffraction analyses, in addition to UV-vis spectral studies. Benesi-Hildebrand plots of the DAC-DNC system in acetonitrile at 300 K in the wavelength range of 620-660 nm indicate a strong EDA interaction with both the thermodynamic formation constant K. and the molar absorptivity ελ. of the order of two. IR spectral, DSC, and XRD data also clearly indicate a strong EDA interaction even in their 1:1 molar mixture in solid state