β-D-核糖(RI)与一价、二价金属离子相互作用的理论研究

Theoretical Study on the Interaction between β-D-ribose(RI) and Bivalent and Monovalent Cations

在HF和MP2水平用全电子(AE)和相对论有效芯势(RECP)方法研究了Ⅰa、Ⅰb、Ⅱa和Ⅱb族金属离子与β-D-核糖(RI)的相互作用.结果表明,RECP能可靠地用于重金属离子;二价金属离子(M2+)比一价金属离子(M+)更易使β-D-核糖(RI)变形;二价金属离子络合物(RI-M2+)比一价金属离子络合物(RI-M+)稳定.电荷布居分析的结果支持上述结论.

The interactions of β D ribose(RI) with metal cations in groups Ia(Li+、Na+、K+、Rb+、Cs+)、Ib(Cu+、Ag+、Au+)、Ⅱa (Mg2+、Ca2+ 、Sr2+ 、Ba2+) and Ⅱb (Zn2+ 、Cd2+ 、Hg2+ ) were studied at the Hartree Fock and MP2 levels employing all electron(AE) and pseudopotential treatments. Relativistic effective core potentials (RECP) were used for all the ions, with the exception of Li+. 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 be used with confidence also for heavy metal cations. However, in order to ensure the precision of computation,EDEF and EBSSE must be taken into account. The deformation of β D ribose caused by bivalent ions are more serious than those caused by monovalent ions. Stabilization energies(ΔE) and interaction Gibbs energies(ΔG) of complexes with bivalent ions are smaller than those with monovalent ions. Therefore, the interaction between bivalent ions and β D ribose is stronger than that between monovalent ions and β D ribose. And in the same group the stability of complexes decreases with increasing atomic number of the metal ions(except the Au+ RI complex), because ΔE and ΔG added with increasing atomic number of the metal ions.