2-吡嗪腈的激发态结构动力学研究  

Study on Structural Dynamics of 2-Cyanopyrazine in Excited State

作　　者：邱朦朦 薛佳丹[1] 王惠钢[1] 

机构地区：[1]浙江理工大学理学院,杭州310018

出　　处：《浙江理工大学学报（自然科学版）》2014年第4期474-480,共7页Journal of Zhejiang Sci-Tech University(Natural Sciences)

摘　　要：采用密度泛函理论计算获得了2-吡嗪腈(2-CP)在气相中的电子吸收光谱,通过实验获得了2-CP在水、甲醇、乙腈和环己烷中的紫外吸收光谱和共振拉曼光谱。在B3LYP/6-311+G(d,p)计算水平上,发现A-带和B-带的电子跃迁主体为π→π*。A-带共振拉曼光谱指认为6个基频的振动模式及其泛频和组合频,其中υ16(N1/N4面内弯曲振动),υ14(吡嗪环呼吸振动),υ10(C2C7伸缩振动+C3H9面内弯曲振动)的基频、泛频和组合频对拉曼光谱强度的贡献最大。在B-带,2-CP的结构反应动力学主要沿着υ5(C2C3/C5C6对称伸缩振动)和υ14(吡嗪环呼吸振动)反应坐标展开。A-带与B-带的主要贡献振动模的强度不同,结果表明,A-带与B-带的激发态反应动力学的结构存在差异。The electronic absorption spectrum of 2-cyanopyrazine（2-CP）in gaseous phase was gained through Density Functional Theory.The UV absorption spectrum and resonance Raman spectrum of 2-CP were obtained experimentally in water,methanol,acetonitrile and cyclohexane solvent respectively.Based on B3LYP/6-311＋G（d,p）calculation,it is found that electronic transition subject of Band A and Band B isπ→π^＊.Resonance Raman spectrum of Band A could be identified as vibration modes of 6fundamental frequencies as well as their overtones and combined frequencies,where fundamental frequencies,overtones and combined frequencies ofυ16（N1/N4in-plane bending vibration）,υ14（pyrazine ring breathing vibration）andυ10（C2C7stretching vibration＋ C3H9in-plane bending vibration）contribute mostly to Raman spectrum intensity.In Band B,structural reaction dynamics of 2-CP mainly spreads along reaction coordinates ofυ5（C2C3/C5C6symmetrical stretching vibration）andυ14（pyrazine ring breathing vibration）.The intensity of the main vibration models of Band A and Band B is different.The result shows that,the structures of reaction dynamics of Band A and Band B in excited state are different.

关 键 词：2-吡嗪腈 紫外光谱 电子跃迁 共振拉曼光谱 密度泛函理论 光诱导反应动力学 

分 类 号：O643.12[理学—物理化学]