与DNA形成电子激发态复合物的水溶铜卟啉Cu（NEAE）的共振拉曼研究

RESONANCE RAMAN SPECTROSCOPIC STUDIES OF ELECTRONICALLY EXCITED WATER-SOLUBLE COPPER-PORPHYRIN Cu(NEAE)TO DNA

本文用４００ｕｍ和４４５ｕｍ脉冲激光激发测量了不同功率条件下的水溶铜卟啉ＣＵ（ＮＥＡＥ）（４－Ｎ－乙酸乙酯基－吡啶基铜卟啉）及其与小牛胸腺脱氧核糖核酸（ＤＮＡ）复合物的共振拉曼光谱。结果表明，ＣＵ（ＮＥＡＥ）与ＤＮＡ形成了电子激发态复合物。首次观察到激发态铜卟啉除拉曼谱带Ⅵ（～１３７０ｃｍ－１）和Ⅷ（～１５７０ｃｍ－１）外Ⅶ带（～１４７０ｃｍ－１）也出现了代表激发态复合物形成的额外峰。激发态复合物形成时卟啉π电子与ＤＮＡ碱基π电子间产生了比基态时强得多的相互作用而使卟啉骨架发生较大畸变，而对吡啶基团的影响则较小。

The resonance Raman spectra of water-soluble copper-porphyrin Cu(NEAE)[Cutetrakis(4-N-ethylacetatepyridyl) porphine] and its complex with calf thymus DNA were measured with 400 and 445urn pulse laser excitation.The analysis indicates that Cu(NEAE) forms electronic exciplex with DNA.It is first observed that porphyrin Ramanband Ⅶ (near 1470cm-1) also shows extra band which symbolizes the formation of exciplex besides bands Ⅵ(near 1370cm-1) and Ⅷ(near 1570cmml).The porphyrin skeleton in exciplex is distorted considerably and the pyridyl rings were not. The interaction between x-electron of porphyrin core of Cu(NEAE) and π-electron of DNA is stronger in exciplex than in ground state.