利用泛密度函數對多硝基芳香族化合物之分子結構及能量之研究

Density Functional Theory Investigation Molecular Structure and Energy of Some Multi-nitro Aromatic compound

揭由志(Y.C. Chieh) ； 陳培中(P.C. Chen)

《化學》 60卷1期 (2002/03) Pp. 51-62

https://doi.org/10.6623/chem.2002006

摘要

由於取代基與苯環間不同之效應，對芳香族硝基化合物之分子結構及能量，會產生不同程度之影響。本研究利用Gaussian 98套裝軟體，以泛密度函數理論中之B3LYP16-311G**方法，對六硝基苯(hexanitrobenzene)，1,3,5-三羥基-2,4,6-三硝基苯(1,3,5-trihydroxy-2,4,6-trinitrobenzene)，及1,3,5-三胺基-2,4,6三硝基苯(1,3,5-triamino-2,4,6-trinitrobenzene)三個多硝基芳香族化合物，以幾何優選，取代基與苯環共平面，及相互垂直等狀態，來探討其分子幾何結構及作能量之比較。結果顯示此三個化合物，以幾何優選所得到之結構，為最穩定之結構。取代基與苯環間之共軛，共振及氫鍵等效應，是造成分子結構及能量產生不同變化之主要原因，而立體效應則是造成取代基與苯環間產生扭轉之重要因素。另外，三個化合物 幾何優選與其它垂直或平面結構的能差，也隨取代基不同而有明顯差異。

關鍵字

泛密度函數 ； 六硝基苯 ； 1.3,5-三羥基-2,4,6-三硝基苯 ； 1,3,5-三胺基-2,4,6-三硝基苯 ； 立體效應

並列摘要

The molecular structure and relative energy of different distortion type of the substituted groups for three fully substituted aromatic nitro compounds such as hexanitrobenzene, 1,3,5-trihydroxy-2,4,6-trintrobenzene, 1,3,5-triamino-2,4,6-trinitrobenzene were calculated by the B3LYP/6-311G** method, considering different molecular geometries. The most favorite molecular structure can be determined by the calculated energies. Calculations indicate that the conjugation, resonance and hydrogen bonding effects play important roles to determine the molecule geometries and energies. Moreover, the steric effect also plays an important role to determine the deformation of the phenyl ring and the distortion of nitro and other substituted groups. The relative energies of different distortion type of the substituted groups are related to the substituted groups.

並列關鍵字

Density functional theory ； hexanitrobenzene ； 1,3,5-trihydroxy-2,4,6-trintrobenzene ； 1,3,5-triamino-2,4,6-trinitrobenzene ； steric effect