%0 Journal Article
%T 内嵌水二聚体富勒烯(H2O)2@C84的基态性质与光谱特性<br>Ground state properties and spectral properties of endohedral water dimer fullerene (H2O)2@C84
%A 杨月菊
%A 蔡绍洪
%A 沈虎峻
%A 隆正文
%J 原子与分子物理学报
%D 2018
%X 采用密度泛函B3LYP方法以6-31G为基组研究了富勒烯D2d(23)―C84和内嵌水二聚体富勒烯(H2O)2@D2d(23)―C84的中性、阴离子及阳离子基态几何结构、稳定性、电荷分布、能量、电偶极矩、能隙、红外及拉曼光谱特性; 用含时的TD-B3LYP方法研究了富勒烯C84和内嵌水二聚体富勒烯(H2O)2@C84的紫外-可见吸收光谱. 研究结果表明: 水二聚体的加入导致了富勒烯分子的对称性降低、偶极矩增加, 体系能隙减小, 同时水二聚体的氢键键长减小. 另外, 水二聚体的加入改变了富勒烯分子的红外和拉曼光谱特征, 如谐振频率的移动以及红外和拉曼峰的增强或减弱. 研究结果显示水二聚体的加入致使富勒烯分子的最大激发波长发生红移, 对其它激发波长的位置以及振子强度也产生影响, 如光学活性（振子强度不为0）的激发态成为光学非活性（振子强度为0）的激发态或者光学非活性的激发态成为光学活性的激发态; 同时研究发现C84存在能量简并的激发态, 而(H2O)2@C84并没有能量简并的激发态; 虽然水二聚体的加入影响富勒烯分子的激发特性, 但计算结果显示C84和(H2O)2@C84经展宽后的紫外-可见光谱轮廓基本一致. 该研究可以为将来的实验光谱测量提供理论依据, 也可以为内嵌水二聚体富勒烯的合成和应用提供理论指导.<br>In this work, density functional theoretical method (B3LYP) with 6-31G basis set has been used to study the equilibrium structures, total energy, the highest occupied molecular orbital (HOMO) energy levels, the lowest unoccupied molecular orbital (LUMO) energy levels, energy gaps, dipole moments, atomic charge distribution, infrared spectra and Raman spectra of fullerene D2d(23)―C84 and endohedral water dimer fullerene (H2O)2@D2d(23)―C84. The UV-Vis absorption spectra (the first 18 excited states containing excited energies, excited wavelengths and oscillator strengths) of fullerene C84 and endohedral water dimer fullerene (H2O)2@C84 are calculated by the time-dependent density functional theory method (TD-B3LYP) with the 6-31G basis set. The results show that water dimer can be stably encapsulated inside the C84 cage. Meanwhile, the addition of water dimer results in lower symmetry (C1) and changes the electronic state. Moreover, the calculated results show that the addition of water dimer can increase electric dipole moment, and decrease energy gap. The addition of water dimer can modify the infrared and Raman spectra, such as shift of vibrational frequencies and weakening of infrared and Raman peaks. Furthermore, the calculated results indicate that the addition of water dimer has effects on the excited states of fullerene C84. It can lead to the redshift of first excited wavelength. With the addition of water dimer, the optically active (with the oscillator strength of nonzero) excited state can become optically inactive (with the oscillator strength of zero) excited state and vice versa. Meanwhile, the weak excited state can become the strongest excited state. However, after the broadening of UV-Vis absorption spectra, UV-Vis absorption spectra of fullerene C84 are basically consistent with those of endohedral water dimer fullerene (H2O)2@C84. Our work can provide theoretical guidance for the application of endohedral water dimer fullerene (H2O)2@C84 in the future.
%K C84 (H2O)2@C84 密度泛函理论 光谱特性&lt
%K br&gt
%K C84 (H2O)2@C84 density functional theory spectral properties
%U http://jamp.ijournals.cn/jamp/ch/reader/view_abstract.aspx?file_no=17153&flag=1