磷酸二甲酯阴离子(DMP-)与一价、二价金属离子相互作用的理论研究

在B3LYP、HF和MP2水平上运用全电子从头算(AE)和相对论有效实势(RECP)及6-311+G**和LanL2DZ基组计算Ⅰa、Ⅰb、Ⅱa和Ⅱb族金属离子与磷酸二甲酯阴离子(DMP-)的相互作用。 RECP用于除Li+、Be2+外所有的金属离子。 对Na+、K+、Cu+、Mg2+、Ca2+、Zn2+用AE和RECP 2种方法处理。 结果表明:RECP能可靠地用于重金属离子络合物; 二价金属离子络合物(DMP-—M2+)比一价金属离子络合物 (DMP-—M+)稳定;二价金属离子(M2+)可能比一价金属离子(M+)更易使多核苷酸折叠。

Theoretical Study on the Interaction Between DMP-and Bivalent and Monovalent cations

The interaction of dimethyl phosphate anion(DMP) with metal cations in groups Ia (Li+,Na+,K+,Rb+,Cs+), Ib (Cu+,Ag+,Au+), Ⅱa (Be2+,Mg2+,Ca2+,Sr2+ ,Ba2+) andⅡb (Zn2+,Cd2+,Hg2+ ) were studied at the levels of density functional theory(DFT), Hartree-Fock and Mφller-Plesset second-order perturbation theory(MP2) employing all electron(AE) and pseudopotential treatments. Relativistic effective core potentials(RECP) were used for all the ions ,with the exception of Li+、Be2+. AE and RECP treatments were tested for the Na+,K+,Cu+,Mg2+,Ca2+ and Zn2+ complexes; good agreement between the results of AE and RECP suggests that pseudopotentials can also be used with confidence for heavy metal cations. The stabilization energies of complexes with bivalent ions are larger than those with monovalent ones . Therefore, the interaction between bivalent ions and DMP is stronger than that between monovalent ions and DMP . In the same group they decrease with the increasing atomic number of the metal ions,and the only exceptions are the Hg+and Au+ complexes. ∠OPO and ∠COP of the complexes with bivalent ions are larger than those with monovalent ions , so it may be easier for bivalent ions then monovalent ones bivalent ions to make polynucleotides folded and winded. The amount of charge transfer (CT) between DMP and bivalent ions is larger than that between DMP and monovalent ions, excepti Cu+ complexe only.The results indicate that the interaction between DMP and bivalent ions is stronger than that between DMP and monovalent ions