In the two stable conformations of the diazabicyclanol 3, 7-dimethyl-3, 7-diazabicyclo[3. 3. 1]nonan-9-ol,chair-chair(Va) andchair-boat(Vb), the infrared spectra (200–4000 cm−1) were recorded, compared and their vibrations analysed. Using the AMI senlempirical method, the geometry was fully optimized in both forms, and the theoretical Infrared spectra were calculated and compared. In the (Vb) conformation, the IR spectra were recorded in CCl3D, CCl4and S2C solvents. Some correlations were established.