摘要
研究了四苯基卟啉金属配合物（ＭＴＰＰ，Ｍ＝Ａｇ，Ｍｇ，Ｃｕ，Ｐｄ）在ＡｇＩ胶体上的表面增强拉曼光谱（ＳＥＲＳ）。结果显示ＭｇＴＰＰ与基底发生金属交换生成ＡｇＴＰＰ，而在ＰｄＴＰＰ和ＣｕＴＰＰ上则未发现金属交换。除卟啉环的振动外，一些苯环振动带也被显著增强。在 １４００～ １６００ｃｍ－１范围，ＰｄＴＰＰ和ＣｕＴＰＰ的ＳＥＲＳ与ＡｇＴＰＰ有很大差别，可能反映了吸附分子在次甲基桥碳原子Ｃｍ附近立体构型的差异。
Surface-enhanced Raman Spectra (SERS) of four metallotetraphenylporphyrins (MTPP, M=Ag, Mg, Cu, Pd) adsorbed on AgI colloid were studied using 632.8nm excitation. It was shown that MgTPP on AgI colloid undergoes a metal exchange reaction with the substrate to form AgTPP, evidenced by appearing characteristic Raman bands of AgTPP in the SERS of MgTPP. In contrary, metal exchange reaction was not observed for CuTPP and PdTPP molecules adsorbed on AgI colloids. In addition to the porphyrin-ring related bands, several monosubstituted benzene bands are also enhanced in the SERS spectra of MTPP. The SERS enhancement patterns of PdTPP and CuTPP in the region of 1400 -1600 cm-1 are very different from that of AgTPP, which can be attributed to the different stereochemistry of the adsorbents around Cm atoms. The present study demonstrates that semiconductors such as AgI can be suitable SERS substrates to study the structure and chemical reactions of adsorbed molecules.
基金
国家自然科学基金资助项目!(NO.29873043)
