Theoretical studies on the absorption and luminescent properties of a series of derivatives of 1,3-diphenyl-5-pyrene-2-yl-4,5-dihydro-1H-pyrazole

摘要

The absorption and emission spectra for a series of substituted l,3-diphenyl-5-pyrene-2-yl-4,5-dihydro-lH-pyrazole (DPPyP) molecules are computed by TDDFT methods.The solvent effect is modeled using the self-consistent reaction field (SCRF) method with Tomasi's polarized continuum model (PCM).The ground-state geometries were optimized by the Hartree-Fock method with the 6-31G basis set (and also with 3-21G~* for molecule A) (HF/6-31G),and the lowest singlet excited-state geometries were optimized at the ab initio CIS level with the 6-31G basis set (CIS/6-31G).The calculated results indicate that the TDDFT method can reproduce the experimental values.We consider the effects of different basis sets on the optimization of the ground-state geometries.Specially,some insights on the differences observed for these compounds in changing the substituted donors (H,CH_3,and NH_2) and acceptor group (CN) are given;the results indicate that introduction of the donor groups will lead emission to be red-shifted,while introduction of the acceptor will induce the emission to be blue-shifted,which provides useful information for modulating light-emitting material colors.