Ben Ahmed A, Feki H, Abid Y
Laboratory of Applied Physics, University of Sciences of Sfax, 3018, BP 802 Tunisia.
Laboratory of Applied Physics, University of Sciences of Sfax, 3018, BP 802 Tunisia.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Dec 10;133:357-64. doi: 10.1016/j.saa.2014.05.073. Epub 2014 Jun 10.
A new organic-inorganic hybrid material, [((CH3)2NH2)(+)]6·[(BiBr6)(3-)]2, has been synthesized and characterized by X-ray diffraction, FT-IR, Raman spectroscopy and UV-Visible absorption. The studied compound crystallizes in the triclinic system, space group P1¯ with the following parameters: a=8.4749(6)(Å), b=17.1392(12)(Å), c=17.1392(12)(Å), α=117.339(0)°, β=99.487(0)°, γ=99.487(0)° and Z=2. The crystal lattice is composed of a two discrete (BiBr6)(3-) anions surrounded by six ((CH3)2NH2)(+) cations. Complex hydrogen bonding interactions between (BiBr6)(3-) and organic cations from a three-dimensional network. Theoretical calculations were performed using density functional theory (DFT) for studying the molecular structure, vibrational spectra and optical properties of the investigated molecule in the ground state. The full geometry optimization of designed system is performed using DFT method at B3LYP/LanL2DZ level of theory using the Gaussian03. The optimized geometrical parameters obtained by DFT calculations are in good agreement with single crystal XRD data. The vibrational spectral data obtained from FT-IR and Raman spectra are assigned based on the results of the theoretical calculations. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) results complements with the experimental findings. The simulated spectra satisfactorily coincide with the experimental UV-Visible spectrum. The results show good consistent with the experiment and confirm the contribution of metal orbital to the HOMO-LUMO boundary.
一种新型有机-无机杂化材料[((CH3)2NH2)(+)]6·[(BiBr6)(3-)]2已通过X射线衍射、傅里叶变换红外光谱、拉曼光谱和紫外-可见吸收光谱进行了合成与表征。所研究的化合物结晶于三斜晶系，空间群为P1¯，具有以下参数：a = 8.4749(6)(Å)，b = 17.1392(12)(Å)，c = 17.1392(12)(Å)，α = 117.339(0)°，β = 99.487(0)°，γ = 99.487(0)°且Z = 2。晶格由两个离散的(BiBr6)(3-)阴离子组成，周围环绕着六个((CH3)2NH2)(+)阳离子。(BiBr6)(3-)与有机阳离子之间的复杂氢键相互作用形成了三维网络。使用密度泛函理论(DFT)进行理论计算，以研究基态下所研究分子的分子结构、振动光谱和光学性质。采用高斯03程序，在B3LYP/LanL2DZ理论水平上使用DFT方法对设计体系进行了全几何优化。DFT计算得到的优化几何参数与单晶XRD数据吻合良好。基于理论计算结果对傅里叶变换红外光谱和拉曼光谱获得的振动光谱数据进行了归属。含时密度泛函理论(TD-DFT)计算得到的能量和振子强度结果与实验结果相互补充。模拟光谱与实验紫外-可见光谱令人满意地吻合。结果表明与实验具有良好的一致性，并证实了金属轨道对HOMO-LUMO边界的贡献。
