The behavior of the ground and the first two excited states ofrnthe compound 4-(N,N-dimethylamino)-benzonitrile (4DMABN) have beenrnstudied using both experimental and theoretical methods. Forrncomparison purpose the ground and the first two excited states of therncompounds 3-(N,N-dimethyl amino)-benzonitrile (3DMABN) and 2,3,6,7-rntetrahydro-1H,5H-pyridol[3,2,1-ij]quinoline-9-carbonitrile (TMABN) havernbeen studied theoretically. The experimentally achieved absorptionrnspectrum of 4DMABN has shown two distinct bands. And the emissionrnspectrum has also two distinct bands, the behavior of which isrndependent on the wavelength of the exciting light. This is attributed tornthe presence of two stable conformers of the compound in the groundrnstate. Excited state calculations using TDDFT method have shown thatrnthe first two excited states of the compound 4DMABN have differentrnproperties in the gaseous and the solvated system. This is in agreementrnwith the experimental result that the compound shows two emissionrnbands in the solvent acetonitrile and one band in the gaseous state. Thernsame theoretical calculation has shown higher excitation energy to the S2rnstate at the perpendicular conformation of the compound 3DMABN. Thisrnagrees with the absence of a CT band in experiment. For the compoundrnTMABN the same calculation has shown for the existence of only onernemitting excited electronic state at a considerably twisted conformation.rnThis is in agreement with the experimentally found single CT band.