title: A novel non-fluorescent excited state intramolecular proton transfer phenomenon induced by intramolecular hydrogen bonds: an experimental and theoretical investigation.
abstract: Two molecules, 1-hydroxypyrene-2-carbaldehyde (HP) and 1-methoxypyrene-2-carbaldehyde (MP) were explored. We investigated their photophysical properties, using experimental transient absorption and theoretical density functional theory/time-dependent density functional theory (DFT/TDDFT). HP and MP have similar geometric conformations but exhibit entirely different photophysical properties upon excitation into the S1 state. In contrast to traditional excited state intramolecular proton transfer (ESIPT) in molecules that exhibit either single or dual fluorescence, HP has an unusual non-fluorescent property. Specifically, the ultrafast ESIPT process occurs in 158 fs and is followed by an intersystem crossing (ISC) component of 11.38 ps. In contrast to HP, MP undergoes only an 8 ps timescale process, which was attributed to interactions between solute and solvent. We concluded that this difference arises from intramolecular hydrogen bonds (IMHBs), which induce drastic structural alterntion upon excitation.
authors.affiliation: Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Yin
authors.affiliation: Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Institute for advanced study, Nanchang University, Nanchang, 330031, China.
authors.forename: Guomin
authors.initials: G
authors.lastname: Xia
authors.affiliation: Institute for advanced study, Nanchang University, Nanchang, 330031, China.
authors.forename: Chengyan
authors.initials: C
authors.lastname: Ruan
authors.affiliation: Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Institute for advanced study, Nanchang University, Nanchang, 330031, China.
authors.forename: Hongming
authors.initials: H
authors.lastname: Wang
authors.affiliation: Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
authors.forename: Mingxing
authors.initials: M
authors.lastname: Jin
authors.affiliation: Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
authors.forename: Dajun
authors.initials: D
authors.lastname: Ding