【作者】 陈昌国； 张代钧； 鲜晓红；

【Author】 Chen Changguo,Zhan Daijun~*,and Xian Xiaohong (Department of Applied Chemistry,* Department of Mining Engineering, Chongqing University,Chongqin 630044)

【机构】 重庆大学化学化工学院； 重庆大学资源与环境工程学院；

【摘要】 <正>煤的电子光谱与煤的颜色、电子能级、稠环芳香结构单元的大小有关,UV-Vis光谱和量子化学计算是研究电子光谱的主要方法。众所周知,煤是黑色的,并随煤化程度的不同或带棕色(褐煤),或带灰色(无烟煤),这就给煤的UV-Vis光谱研究带来了许多困难,故此仅在50～60年代有少量报道。Friedel和Queiser用超薄切片(10±0.5μm)和KBr压片技术得到煤的UV-Vis吸收光谱。由于煤中缩合芳环大小不一,实际上是各种稠环芳香结构单元的更多还原

【Abstract】 The electronic spectra of coal were studied by ultraviolet-visible（UV-Vis） diffuse reflection spectroscopy（DRS） and quantum chemical discrete variation（DV） X_∞method.The UV-Vis-DRS of bituminous coal and anthracite shows a broadening absorption band at 540,850nm respectively,which indicated that the condensed aromatic ring in bituminous coal is small than in anthracite.DV-Xcc calculation result of electronic spectrum of benzene molecular is consistent with the expriment. The model molecular of coal is propsoed,which is C₄₂H₁₈ with 13 benzene rings and D_6h symmetry.DV-Xcc calculation shows that the model molecular has a maximum absorption wavelengthλ_max=537 nm from HOMO→LUMO transition, which is much less than the absorption wavelength limit 760nm of black color substance, such as coal,graphite,etc.Hence,the condensed aromatic structure unit of coal should have more than 13 benzene rings.更多还原