Structural and vibrational studies of some medically important molecules by using AB initio and DFT method

This work, consists of the accounts of vibrational frequencies (Infared and Raman) thanks to 2,2?-bipyridine, 2,3?-bipyridine, 2,4?-bipyridine, 2,5?-bipyridine, 2,6?- bipyridine, 3,3? bipyridine -, 3,4?- bipyridine, 3,5?- bipyridine, 3,6?-, bipyridine, 4,4?- bipyridine molecules with the help of the program Gaussian 03W and B3LYP/ 6-311+g(d,p), MPW1PW91/dgdzvp, MPW1PW91/6-311+g(d,p) , HF/ dgdzvp, HF/6-311+g(d,p) with the methods and gen [by optimizing the structural parameters of those determined molecules ( at the lowest energy level) ( the length of the connections, connection angle). Theoretically, the structural parameters and frequencies that we gain are compared with the experimental structural parameters and frequencies.