摘要
为从微观上说明荧光物质与溶剂分子间的相互作用,采用荧光光谱研究了不同溶剂极性及质子溶剂对羟乙基纤维素(HEC)/Eu(Ⅲ)、甲基纤维素(MC)/Eu(Ⅲ)、羧甲基纤维素(CMC)/Eu(Ⅲ)配合物溶液荧光性能的影响.结果表明:随着H2O/CH3OH溶剂体系极性的增大,HEC/Eu(Ⅲ)配合物的激发态荧光体偶极矩发生较大的改变,导致荧光光谱波长向长波方向位移,其荧光强度变化则与更多因素有关;而质子溶剂H2O/HAc中质子浓度的增大使得MC/Eu(Ⅲ)配合物周围的溶剂笼产生重组,溶剂驰豫使其荧光光谱波长的Stokes位移增大;H2O/CH3COCH3溶剂体系极性的增强对CMC/Eu(Ⅲ)配合物Stokes位移的影响不明显,但会破坏该配合物分子内和分子间氢键的平衡,导致发光体结构的改变,从而使其荧光光谱的强度发生变化.
The effects of solvent polarity and protonic solvent on the fluorescent properties of hydroxyethyl cellulose （HEC）/Eu（ Ⅲ ） , methyl cellulose （MC）/Eu（ Ⅲ ） and earboxymethyl cellulose （CMC）/Eu（Ⅲ ） complexes were investigated by fluorescent spectroscopy to reveal the interaction between the fluorescent substance and the solvent on the microcosmic level. The results show that （ 1 ） the dipole moment of HEC/Eu （Ⅲ） complex in the excited state greatly changes with the increase in the polarity of HEO/CH3OH solvent, which makes the fluorescent spectrum of HEC/Eu （Ⅲ ） complex, whose intensity depends on various factors, shifts to the long-wavelength side ; （2） the increase in the H ＋ concentration of H2O/HAc solvent results in a reorientation of the solvent cages around MC/ Eu （Ⅲ ） complex as well as a great Stokes shift of the fluorescent spectrum due to the solvent relaxation ; and （3） the increase in the polarity of HEO/CH3COCH3 solvent has no obvious effect on the Stokes shift of CMC/Eu（ Ⅲ） complex, but it may break the equilibrium between intra- and inter-molecular hydrogen bonds in the complexes, thus changing the structure of the fluorescent substance and the intensities of the fluorescent spectra .
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第8期75-78,共4页
Journal of South China University of Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(50573025
20436020)
