过渡金属表面α-吡啶基的振动光谱学判据  

Vibrational Spectroscopy Criteria to Determine α-Pyridyl Adsorbed on Transition Metal Surfaces

作　　者：苏抒[1] 黄荣[1] 赵刘斌[1] 吴德印[1] 田中群[1] 

机构地区：[1]固体表面物理化学国家重点实验室厦门大学化学化工学院化学系,福建厦门361005

出　　处：《物理化学学报》2011年第4期781-792,共12页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20973143,91027009);国家重点基础研究发展规划(973)(2007CB815303,2009CB930703);厦门大学(2010121020);国家科学人才培养基金(J1030415)资助项目~~

摘　　要：基于簇模型采用密度泛函理论在B3LYP/6-311+G**/LANL2DZ(metal)基组水平上计算了吡啶及α-吡啶基吸附于Pt、Pd、Rh、Ni四种金属表面的红外和拉曼光谱.通过详细地分析和比较计算结果与文献报道的实验谱图,提出了以N端吸附的吡啶分子和α-吡啶基这两种表面物种各自存在的谱学判据.计算结果表明在以上四种金属表面,α-吡啶基的拉曼活性比吡啶的小,而特征谱峰的红外强度与吡啶相当.该结果表明红外光谱是检测金属表面α-吡啶基的有效手段,也解释了采用表面增强拉曼光谱和红外光谱研究吡啶吸附在金属表面得出不同结构的原因.Density functional theory calculations at the B3LYP/6-311＋G＊＊/LANL2DZ（metal） level were used to predict the infrared （IR） and Raman spectra for pyridine and α-pyridyl upon interaction with platinum （Pt）, palladium （Pd）, rhodium （Rh）, and nickel （Ni） clusters. After carefully comparing the simulated IR and Raman spectra with the corresponding experimental spectra from literature, the characteristic frequencies for the metal surface adsorbed pyridine and α-pyridyl were determined. Our results show that on these metal surfaces α-pyridyl has a far lower Raman activity compared with pyridine, but their characteristic frequencies have comparable IR intensities. This is the reason why different adsorption configurations are proposed for the IR and the surface-enhanced Raman spectra （SERS）. Our results indicate that IR spectroscopy is an effective tool to detect α-pyridyl adsorbed on metal surface.

关 键 词：红外光谱 表面增强拉曼光谱 吡啶 α-吡啶基 

分 类 号：O626.32[理学—有机化学]