Computational Study of the Interactions of Transition Metal Complexes with Biomolecules Using Quantum Chemical Methods.

It has been proven that platinum complexes are active in anticancer treatment as well as several other transition metals. There is an effort in recent medicine to replace cisplatin complexes by drugs with smaller side effects. This work focuses on the reaction of 5'-dGMP (2'-deoxyguanosine- 5'˗monophosphate) with a platinum complex PtIV (dach)Cl4 (dach=diaminocyclohexane) forming PtIV (dach)Cl3(N7-cGMP) complex. The explored reaction can be divided into two (independent) steps: cyclization of phosphate and substitution reaction where a new complex with coordinate- covalent bond between platinum atom and nitrogen N7 of guanine is formed releasing chloride particle. Here I studied geometry parameters which are important in the above mentioned reaction. The reaction course is observed from the thermodynamic point of view. The structures were optimized at the DFT level with B3LYP functional in basis set 6-31G* and PCM/UA0 solvation model. The energy parameters and electron density distribution were computed at the B3LYP/6˗311++G(2df,2pd) level in the D˗PCM/sUAKS solvation model