三明治型酞菁稀土配合物M(Pc)_2电子吸收光谱的离子半径效应

Effect of Ionic Size on Electronic Absorption Spectra of Bis(phthalocyaninato) Rare Earth Complexes MⅢ(Pc)_2

系统研究了对称三明治型二层酞菁稀土配合物M(Pc)2在300～800am范围内的电子吸收光谱,首次采用导数光谱对光谱区域内的叠加谱带及肩带进行了分离,并求算了相应吸收的摩尔吸光系数.结果表明,该系列酞菁稀土配合物的Soret带都分裂两个吸收峰,配合物的吸收谱带除位于Soret带低能一侧和酞菁π阴离子自由基吸收高能一侧的吸收以外均随镧系收缩发生蓝移,但Soret带蓝移程度较小,其余谱带吸收波长与稀土离子半径呈现线性关系;配合物电子吸收光谱中,叠加谱带相邻两吸收峰的强度比随镧系收缩发生规律性变化,与稀土离子半径也存在良好的线性关系,表现出明显的离子半径效应.

The electronic absorption spectra in the region of 300~800 nm for a series of homoleptic unsubstituted bis(phthalocyaninato) rare earth complexes M(Pc)2 have been investigated. The shoulder and overlapped bands in this region have been separated with the second derivative method. The molar absorbance coefficients for all of the absorption bands were calculated. For this series of rare earth complexes, the Soret bands split into two bands. All of the absorption bands, except the Soret absorption at the lower energy side and the ones for Pc·- at ca. 460 and 480 nm, are dependent on the size of the central rare earth, shifting to higher energy along with lanthanide contraction. The relative intensities of the neighboring bands in the overlapped bands are also metal-sensitive.