【摘要】 研究了四苯基卟啉 (H2 TPP)及其金属配合物 (AgTPP和MgTPP)在AgBr胶体上的表面增强喇曼光谱 (SERS)。SERS光谱表明 ,吸附在AgBr胶体粒子表面的MgTPP和H2 TPP分子分别发生银离子交换和银配位反应生成AgTPP ,这种表面反应可能与激光照射有关。AgTPP分子在胶体粒子表面的吸附导致卟啉大环的非平面化 ,使ν8振动 (M -N键伸缩振动 )向高波数方向移动近10cm- 1。 632 .8nm激发下的表面喇曼谱以化学增强为主 ,而 4 88.0nm激发下表面喇曼谱除化学增强效应外 ,还存在共振增强效应。更多还原

【Abstract】 SurfaceEnhanced Raman Spectra (SERS) of freebase tetraphenylporphyrin (H 2TPP) and its Ag, Mgchelates (AgTPP and MgTPP) adsorbed on AgBr colloid were studied by 632.8 and 488.0nm excitation. The SERS results show that the adsorbed MgTPP (or H 2TPP) molecules undergo silverexchange (or silverincorporation) reaction to form AgTPP. The chavge transfer mechanism is believed to be the major origin of Raman enhancement for both 632.8 and 488.0nm excitation lines. For 488.0nm excitation, additional mechanism of electronic preresonance effect also contributes to the Raman enhancement, resulting in a slightly different SERS spectra compared with 632.8nm excitation.更多还原