Performance of Different DFT/ECP Combinations in the Study of Platinum Anticancer Drugs

摘要

In the present study the performance of several combinations of ab initio molecular orbital methods was evaluated, aiming at a thorough conformational analysis of the well-known anticancer agent cisplatin (cis-diamminedichloroplatinum (II), cDDP). Different DFT/ECP approaches were tested, coupling the relativistic ECP's CEP-4G/CEP-31G and LANL2MB/LANL2DZ to the DFT approximations B3LYP and mPW1PW. From an energetic point of view, the results obtained were compared with the ones yielded by the AE basis sets 6-31G~* and 6-311G~(**) (at both the HF and MP2 levels). The type of ECP considered and inclusion of an f-polarisation function at the Pt valence shell were found to be determinant for an accurate reproduction of the AE results for this Pt(II) chelate, while the effect of the DFT protocol used proved to be of little significance.