量子化学法研究苯并芘分子的结构和性质

结合HF、B3LYP、B3PW91、MP2等不同经典量子化学方法,在6-311++G(d,p)水平上计算苯并芘的分子结构和电子结构,并对苯并芘分子的几何构型、Wiberg键级、光谱、静电荷布居等进行分析,结合前线轨道理论探讨分子的稳定性和反应活性.结果表明:苯并芘分子呈环状平面型,其中碳原子的活性不同,C(8)的反应活性最高,最容易接受亲电试剂的进攻.前线轨道分析表明:苯并芘分子以接受电子为主,计算得出ΔE L-H=3.048 eV,表明该分子具有适合的能带宽度,可作为有机发光材料的原料.同时计算其在不同温度下的热力学性质.MP2方法在能量计算方面体现出较精确的优势.

Structures and properties of Benzoapyrene by quantum chemistry method

The molecular structure and electronic structures of benzopyrene were studied by the four quantum chemistry methods of HF, B3LYP, B3PW91 and MP2 on 6-311＋＋G（d, p） basis set. By analysis of the geometric structure, Wiberg bond order, spectrum and atomic charge population, which was consistent with the frontier molecular orbital theory knowledge, the stability and the reactivity of benzoapyrene were explored. The results showed that benzoapyrene molecular was annular planar type, where the activity of the carbon atoms was different, and the reactivity of the C（8） was the highest and most easily accepted electrophilic reagent. Frontier orbital analysis showed that benzaopyrene molecule mainly accepted electrons. AEL_H = 3.048 eV showed that the molecule had a suitable energy band width, which can be used as a raw material of the organic light emitting material. Some different methods were used to research the thermodynamic properties of benzopyrene, and some thermodynamics property parameters at different temperatures were found. Furthermore, MP2 method showed more accurate advantage in energy calculation.