IR VIBRATIONAL SPECTRA OF H-BONDED COMPLEXES OF ADENINE, 2- AMINOPURINE AND 2-AMINOPURINE~+ WITH CYTOSINE AND THYIVI INE: QUANTUM-CHEMICAL STUDY

摘要

Using theoretical study on the B3LYp/6-31 1++G(d, p) level of theory, we have compared vibrational spectra of 2-aminopurine (as neutral or protonated at NI atom species) with adenine and H-bonded complexes of 2-aminopurine (as neutral or protoned at N1 atom species) paired with cytosine or thymine with adenine·cytosine and adenine·thymine base pairs. The nature of the base pairing between adenine, 2aminopurine, 2-aminopurine+ and cytosine or thymine have been investigated by means of quantum-mechanical calculations. The main differences in the vibrational spectra as for bases so for base pairs have been observed in the high-frequency region. We have investigated the effect of the hydrogen bonds formation on the vibrational spectra of the investigated base pairs.