title: Resonance Raman spectroscopy and density functional theory calculation study of photodecay dynamics of tetra(4-carboxyphenyl) porphyrin.
abstract: The 397.9 nm, 416.0 nm and 435.7 nm resonance Raman spectra were acquired for meso-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in tetrahydrofuran solution, and the Raman effect of relaxation dynamics was analyzed according to Herzberg-Teller (vibronic coupling) contributions. Density functional calculations were done to help the elucidation of the Soret (B(x) and B(y)-band) electronic transitions and the corresponding photo relaxation dynamics of TCPP. The spectra indicate that the Franck-Condon region photo relaxation dynamics upon S(0) → S(4) electronic transition are predominantly along the totally symmetric C(m)-ph stretch and Porphin ring breath stretch, and simultaneously along the asymmetric ν(C(m)-Phenyl) + δ(N-H) and ν(C(α)-C(m)-C(α))(as) + def (pyr) vibrational relaxation processes. The excited state structural dynamics of TCPP determined from the resonance Raman spectra show that the internal conversion between the B(y) and B(x) electronic states occurs in tens of femtoseconds, and the electronic relaxation dynamics were firstly interpreted taking into account the time-dependent wave packet theory and Herzberg-Teller (vibronic coupling) contributions.
authors.affiliation: Department of Chemistry and State Key Laboratory of advanced Textiles Materials and Manufacture Technology, MOE, Zhejiang Sci-Tech University, Hangzhou 310018, China.
authors.forename: Junmin
authors.initials: J
authors.lastname: Wan
authors.forename: Huigang
authors.initials: H
authors.lastname: Wang
authors.forename: Zhangzhu
authors.initials: Z
authors.lastname: Wu
authors.forename: Yeung Chi
authors.initials: YC
authors.lastname: Shun
authors.forename: Xuming
authors.initials: X
authors.lastname: Zheng
authors.forename: David Lee
authors.initials: DL
authors.lastname: Phillips
mesh_terms: D008958:Models, Molecular; D011166:Porphyrins / Q000737:chemistry*; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D011166:Porphyrins; C018395:tetracarboxyphenylporphine