Theoretical Study Of Structures And Stability Of Molecules Or Ions Containing Ge Or Ng(Ng=Ar, Kr And Xe), And Spectra Of Cu-containing Polynuclear Complex

Generally, noble gas (Ng) atoms have stable electronic configuration, thus the problem about their chemical bonding has attracted the considerable attention of both chemists and physicists. Small molecules containing Ng have wide and valuable applications in spectroscopy, synthetic chemistry, catalytic chemistry and excimer lasers. When study the macroscopic and microscopic properties of the noble gas compounds, quantum chemical theory method is a necessary means. The small molecules of C, N, Si, P or Ge(ion and radical) have received attention in many fields. Si, P and Ge are important components of microelectronics device materials. One of an important reasons is that some species which contain Si, P or Ge, e.g. CP, CSi and C₄Si have been detected in interstellar space, and the discovery of interstellar molecular has a significance in interstellar chemistry.Luminescence materials have extensive application, and it is of significance to study the emitting mechanism theoretically. The theoretical calculation method will not only clarify emitting mechanism of luminescent materials, but also will help us to design and explore new luminescent materials.In this thesis, we theoretically explored the structures, stabilities and spectroscopies of the small species containing Ng and Ge. At the same time, we also calculated the absorption and emission spectra of polynuclear complex containing Cu. The calculated results can be summerized as followings:1. Using the scheme which combined with electronegative atom (fluorine) and electron-deficient atom (boron) to construct BNgF(Ng=Ar, Kr, and Xe) species. The structures, stabilities, charge redistribution, bonding nature, and harmonic vibrational frequencies of BNgF species have been investigated using ab initio quantum chemical methods. It is shown that BXeF specie is of large kinetic stability.2. Using the scheme which combines with electronegative atom (fluorine) and electron-deficient atom (boron) to construct [Ng, B, 2F]⁺(Ng=Ar, Kr, and Xe) cations. The structures of isomer and related transition states, stabilities, charge redistribution, bonding nature, and harmonic vibrational frequencies of [Ng, B, 2F]⁺ species have been investigated using ab initio quantum chemical methods. It is shown that, NgBF₂⁺(C_2v) isomers are of large thermodynamic and kinetic stability and FNgBF⁺ isomers are just kinetically stable.3. After the theoretical study on structures and stability of GeSiN and GeCP radicals, it is shown that GeNSi 1,GeCP 1 and cGeCP 2 are of large thermodynamic and kinetic stability on the potential-energy surfaces (PES) of GeSiN and GeCP.4. The complexes [Cu6L3] (L=p-xylylene-bis(3,5-di-methyl)pyrazol-4-yl) has been investigated using ab initio quantum chemical methods. We identified both the absorption and emission spectrum, found the the existence of copper-copper interaction, and interperated the reason of large Stokes'shift.