Theoritical Study Of Optical Properties Of Gold Nanoring Structures And Electronic Properties Of Transition Metal Binuclear Complexes

The extinction spectra and electric field distribution of gold nanoring structures(the single nanoring with circular and rectangular cross section, the horizontal and vertical arrangement dimer and trimer gold nanoring structures, the concentric gold nanoring and nanoplate structures) and the gold nanoplate structure have been calculated by using the discrete dipole approximation method. It is found that the plasmon resonance peaks can be red-shift or blue-shift with the changes of the radius size, separation gaps, arrangement modes, and the shape of the nanorings. The plasmon resonance extinction peak of gold nanoring is decision to ratio between diameter and thickness. At the main plasmon peak, the nanoring with circular cross section has much stronger electric fields and larger electric field distribution than the nanoring with rectangular cross section and the nanoplate; It shows that the greater separation gap with the weaker local electric fields distribution; there is significant local electric field enhancement by plasmon coupling in the horizontal arrangement dimer and trimer gold nanoring structures and the concentric gold nanoring and nanoplate structures; It demonstrate that the horizontal arrangement trimer gold nanoring structures has stronger enhancement of local electric fields than that of dimer, It shows that the concentric gold nanostructures engender more stronger electric field than those aroused by single gold nanoring or nanoplate. The binuclear complexes (CioH8)2M2(M=Ti, V, Cr, Mn, Fe, Co, and Ni) and C10H8Mn2(CO)n (n=6,5,4,3,2) are predicted by employing density functional theory (DFT) methods(B3LYP and BP86), This structures are found by density functional theory to be the lowest energy and metal-metal bonding and Wiberg bond indices (WBIs) of binuclear complexes (C10H8)2M2(M=Ti, V, Cr, Mn. Fe, Co and Ni) and C10H8Mn2(CCO)n (n=6,5,4,3,2) structures. This study of binuclear complexes.provide examples of four types of azulene ligands in the low energy structures.In the first chapter, we introduce the background and significance of the binuclear complexes and metallic nanomaterial, the auther gives a briefly introduction of the foundation of plasma and plasma physics, nanomaterial, and local surface plasmon resonance optical of metal nanoparticles, also, has introduced the foundation and progress in surface-enhanced Raman spectroscopy and enhancement mechanism of surface-enhanced Raman, also, expatiate the research aim, development of status quo. and explain the study content for the thesis. In chapter2, the auther gives a brief introduction of and the enhancement mechanism of research method of surface enhancement Raman scattering--iscrete dipole approximation, also, has introduced the foundation and progress of density functional theory (DFT).In the chapter3, the extinction spectra and electric field distribution of gold nanoring, the gold nanoplate, the horizontal and vertical arrangement dimer and trimer gold nanoring, and concentric gold nanoring and nanoplate structures have been calculated by using the discrete dipole approximation method.In the chapter4, the binuclear complexes (C10H8Mn2(CO)n(n=6,5,4,3,2) and (C10H8)2M2(M=Ti, V, Cr, Mn, Fe, Co, and Ni) are predicted by employing density functional theory (DFT) methods(B3LYP and BP86). This cis and trans geometries structures are found by density functional theory to be the lowest energy and metal-metal bonding and Wiberg bond indices (WBIs) of binuclear complexes (C10H8Mn2(CO)N(n=6,5,4,3,2) and (C10H8)2M2(M=Ti, V, Cr, Mn, Fe, Co, and Ni) structures. This study of binuclear complexes provide examples of four types of azulene ligands in the low energy structures.The final chapter gives the conclusion and prospect of the paper.