不对称取代方酸内盐衍生物电子结构和光谱的理论研究

THEORETICAL STUDIES ON THE STRUCTURES AND SPECTRA FOR UNSYMMETRICAL SQUARYLIUM DERIVATIVES

采用ＰＭ３ 系列方法对新合成的１０ 个不对称取代方酸内钅翁盐进行了系统研究．计算得到它们的优化几何构型、电荷分布、ＩＲ谱及ＵＶ谱，并对光谱进行了理论确认．考察了组态数对理论ＵＶ谱的影响．结果表明它们都具有刚性平面结构：方酸环为缺电子中心：对前线轨道的能量分析说明这１０ 个衍生物的一价负离子可以稳定存在，随着组态数目的增加，理论ＵＶ谱与实验结果的误差呈减小趋势．所有的光谱理论值和实验值的误差在１０％ 左右．

The PM3 series methods were used to study ten newly synthesized unsymmetrical squarylium derivatives.Their optimized structure,charge distribution,IR and UV spectra were calculated.It is indicated that the configurations of them are rigid planar and they contain a highly polar and electron withdrawing central squaraine(C 4O 2).The energy analysis of frontier orbital show their anion may be stable.With the increase of the configuration numbers,the error between theoretical and experimental UV spectra decreases gradually.All calculated IR and UV spectra reproduced the experimental value with error in 10%.