Theoretical Study On Halogen Bond Of Cyclic ?IX?_n?X=F,OH,NH₂;n=3-5? And M?IX?₄(M=Li⁺,Na⁺,Be²⁺,Mg²⁺;X=SH,F,OH,NH₂)

One of the most important intermolecular weak interactions is the halogen bond.Halogen bond plays great role in the fields of chemistry,material and bioscience.Attracted the attention of many theoretical chemists and experimental chemists,the research on halogen-bonded clusters has not only theoretical value,but also practical significance.In the first chapter,the definition and nature of halogen bond were elaborated systemically based on the physical feature of the molecular surface electrostatic potential.The nature of cooperative effect and development of halogen-bondde compounds are introduced.The second chapter introduces the application of the theoretical methods,including density functional theory,molecular electrostatic potential?MEP?,atoms in molecules?AIM?theories,natural bond orbital?NBO?and basis set superposition error?BSSE?.The computer software contained multifunctional wavefunction analyzer and Gaussian09 are introduced.In the third chapter,using MP2,density functional PBEPBE and M06-2X methods,with standard Pople-style 6-311++G?d,p?basis set for X and lanl2 dz for Iodine,the geometry,energies,AIM analyses,NBO analyses and vibrational frequency shifts of?IX?n?X=F,OH,NH2;n=3-5?are studied.The results reported in this study show that cooperatively effect which acts through the system of the halogen-bonded clusters.In the fourth chapter,using the density functional PBEPBE and M06-2X method,with standard Pople-style 6-311++G?d,p?basis set for X and lanl2 dz for Iodine,the geometry,energies,AIM analyses,NBO analyses and vibrational frequency shifts of M?IX?4(M=Li+,Na+,Be²⁺,Mg²⁺;X=SH,F,OH,NH₂)are studied.