We present a detailed analysis of the structure and infrared spectra of 2,2'-biquinoline. The vibrational frequencies of the 2,2'-biquinoline molecule have been analyzed using standard quantum chemical techniques. Frequencies have been calculated with HF, and DFT (BLYP, B3LYP and B3PW91) theory, using the standard 6-311G* as the basis set. The assignments of the observed bands corresponding to 2,2'-biquinoline were made on the basis of such calculations and the comparison with related molecules. (c) 2006 Elsevier B.V. All rights reserved.