六元卟啉Hexaphyrin(1.1.1.1.1.1)的Pd(Ⅱ)金属配合物光电性质的理论研究

Theoretical investingation on electronic transition of Pd(Ⅱ) complexes of hexaphyrin(1.1.1.1.1.1)

通过密度泛函和含时密度泛函方法对六元卟啉的钯金属配合物进行了系统的研究,探讨了几种金属配合物光学性质的变化.对于具有26π电子体系3个单金属配合物在Q带的最大吸收峰顺序为λmax(D26Pd)>λmax(R26Pd)>λmax(M28Pd),这同它们的ΔEH-L成反比.其中D26Pd和M28Pd的跃迁来自于π→π*的ILCT的跃迁,而R26Pd有部分金属d轨道参与到跃迁,跃迁性质为ILCT/MLCT.它们的B带的强吸收峰同自由状态下的配体的吸收光谱比较,配合物的吸收峰发生了约20nm左右的蓝移,吸收主要贡献都是来自于d(metal)→π*的MLCT的跃迁.非芳香性配合物M28Pd2α的跃迁性质则不同,无论是Q带还是B带都没有发现金属的参与,而且吸收强度明显降低.

The electronic properties of Pd（ Ⅱ ） complexes of [26]Hexaphyrin （1.1.1.1.1.1） were investigated using DFT and TD-DFT methods. For the three aromatic monometallic complexes, the maximal absorption shows λmax （D26Pd） 〉λmox （R26Pd）〉λmax （M28Pd） that is inverse proportion with the AEH L. Compared with the corresponding ligands, maximal absorptions of D26Pd and M28Pd have a blue shift, but R26Pd bring forth the red shift. For the D26Pd and M28Pd, the main contribution of the Q-like bands is the π→π＊ transition, which comes from ILCT. For the R26Pd, d orbital of the Pd （ II ） partly participated in the transition of Q-like bands, which comes from ILCT and MLCT. Compared with the free ligands, absorption of complexes that is d（metal）→π＊ coming from MLCT shows about 20 nm blue shift in the B-like band.