理论预测Al^3+与一种萘酚衍生物荧光探针分子形成配合物的结构

Theoretical prediction of structure for complex between Al^3+and a fluorescent probe based on naphthol

用量子化学方法研究了实验上合成的一种基于萘酚的Al^3+荧光探针分子L的性质.筛选出了L与Al^3+可能形成的配合物的几何结构,并通过电子吸收光谱和荧光光谱进行了验证.在该配合物中,L与Al^3+的络合比为2∶2;Al^3+采用六配位的结构;与萘环相连的氧原子形成氧桥,将两个Al^3+连接起来.最后研究了L与Al^3+生成不同配比化合物的反应焓变和吉布斯自由能变.结果表明,L与Al^3+的络合比为2∶2时反应焓变和吉布斯自由能变最负,反应最可能发生.这一工作加深了人们对这一识别过程的理解.

The properties of an Al^3+fluorescent probe synthesized experimentally based on naphthol were investigated by quantum chemical approach.The possible geometry of L-Al^3+complex was obtained and was confirmed by electronic absorption spectrum and fluorescent spectrum.In the formation of 2∶2 complex,Al^3+adopts six coordination structure.The oxygen atom connected with naphthalene ring forms oxygen bridge,connecting two Al^3+.At last,the changes of enthalpy and Gibbs free energy for the reactions between L and Al^3+with different ratios were calculated.It was found that when the ratio was 2∶2,the changes of enthalpy and Gibbs free energy were the most negative,and the corresponding reaction was most likely to occur.This work deepens the understanding of the sensing process.