Owing to the importance of excited state dynamical relaxation, the excited state intramolecular proton transfer(ESIPT) mechanism for a novel compound containing dual hydrogen bond(abbreviated as "1-enol") is...Owing to the importance of excited state dynamical relaxation, the excited state intramolecular proton transfer(ESIPT) mechanism for a novel compound containing dual hydrogen bond(abbreviated as "1-enol") is studied in this work.Using density functional theory(DFT) and time-dependent density functional theory(TDDFT) method, the experimental electronic spectra can be reproduced for 1-enol compound. We first verify the formation of dual intramolecular hydrogen bonds, and then confirm that the dual hydrogen bond should be strengthened in the first excited state. The photo-excitation process is analyzed by using frontier molecular orbital(HOMO and LUMO) for 1-enol compound. The obvious intramolecular charge transfer(ICT) provides the driving force to effectively facilitate the ESIPT process in the S1 state. Exploration of the constructed S0-state and S1-state potential energy surface(PES) reveals that only the excited state intramolecular single proton transfer occurs for 1-enol system, which makes up for the deficiencies in previous experiment.展开更多
Density functional theory（DFT） and time-dependent density functional theory（TDDFT） methods are used to investigate the influences of intramolecular and intermolecular hydrogen bonding on excited-state intramolecul...Density functional theory（DFT） and time-dependent density functional theory（TDDFT） methods are used to investigate the influences of intramolecular and intermolecular hydrogen bonding on excited-state intramolecular proton transfer（ESIPT） for the 4-N,N-（diethylamino）-2-hydroxybenzaldehyde（DEAHB）. The structures of DEAHB and its hydrogenbonded complex in the ground-state and the excited-state are optimized. In addition, the detailed descriptions of frontier molecular orbitals of the DEAHB monomer and DEAHB-DMSO complex are presented. Moreover, the transition density matrix is worked out to gain deeper insight into the orbitals change. It is hoped that the present work not only elaborates different influence mechanisms between intramolecular and intermolecular hydrogen bonding interactions on the ESIPT process for DEAHB, but also may be helpful to design and develop new materials and applications involved DEAHB systems in the future.展开更多
The influences of the substituent base position on the excited state intramolecular proton transfer fluorescence properties were explored in 2-(2'-hydroxyphenyl)imidazo[1,2-a]-pyridine(HPIP)and HPIP's derivati...The influences of the substituent base position on the excited state intramolecular proton transfer fluorescence properties were explored in 2-(2'-hydroxyphenyl)imidazo[1,2-a]-pyridine(HPIP)and HPIP's derivatives(5'Br-HPIP and 6'BrHPIP).And the density functional theory(DFT)and time-dependent DFT(TD-DFT)methods were used to calculate the molecule structures.The calculated results showed that the influence of 5'Br-HPIP on the fluorescence intensity is stronger than that of 6'Br-HPIP.The fluorescence emission peak of 5'Br-HPIP occurred a blue shift compared with HPIP,and 6'BrHPIP exhibited an opposite red shift.The change of the fluorescence emission peak was attributed to the decrease of the energy gap from 6'Br-HPIP to 5'Br-HPIP.Our work on the substituent position influence could be helpful to design and develop new materials.展开更多
o-hydroxyphenyl-triazine derivatives with formyl substituents were surveyed for the excited state intramolecular proton transfer (ESIPT).The occurrence of ESIPT was confirmed by well-separated emission bands for the d...o-hydroxyphenyl-triazine derivatives with formyl substituents were surveyed for the excited state intramolecular proton transfer (ESIPT).The occurrence of ESIPT was confirmed by well-separated emission bands for the derivatives.A low energy change from enol to keto in the excited state explains ESIPT for the derivatives.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11404112)the Funding Scheme for Young Teachers in Colleges and Universities in Henan Province,China(Grant No.2017GGJS077)the Key Scientific Research Project of Colleges and Universities of Henan Province,China(Grant No.18A140023)
文摘Owing to the importance of excited state dynamical relaxation, the excited state intramolecular proton transfer(ESIPT) mechanism for a novel compound containing dual hydrogen bond(abbreviated as "1-enol") is studied in this work.Using density functional theory(DFT) and time-dependent density functional theory(TDDFT) method, the experimental electronic spectra can be reproduced for 1-enol compound. We first verify the formation of dual intramolecular hydrogen bonds, and then confirm that the dual hydrogen bond should be strengthened in the first excited state. The photo-excitation process is analyzed by using frontier molecular orbital(HOMO and LUMO) for 1-enol compound. The obvious intramolecular charge transfer(ICT) provides the driving force to effectively facilitate the ESIPT process in the S1 state. Exploration of the constructed S0-state and S1-state potential energy surface(PES) reveals that only the excited state intramolecular single proton transfer occurs for 1-enol system, which makes up for the deficiencies in previous experiment.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB922204)the National Natural Science Foundation of China(Grant Nos.11574115 and 11704146)
文摘Density functional theory（DFT） and time-dependent density functional theory（TDDFT） methods are used to investigate the influences of intramolecular and intermolecular hydrogen bonding on excited-state intramolecular proton transfer（ESIPT） for the 4-N,N-（diethylamino）-2-hydroxybenzaldehyde（DEAHB）. The structures of DEAHB and its hydrogenbonded complex in the ground-state and the excited-state are optimized. In addition, the detailed descriptions of frontier molecular orbitals of the DEAHB monomer and DEAHB-DMSO complex are presented. Moreover, the transition density matrix is worked out to gain deeper insight into the orbitals change. It is hoped that the present work not only elaborates different influence mechanisms between intramolecular and intermolecular hydrogen bonding interactions on the ESIPT process for DEAHB, but also may be helpful to design and develop new materials and applications involved DEAHB systems in the future.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874180 and 11704146)the Program of Science and Technology Development Plan of Jilin Province,China(Grant Nos.20190201138TC and 20190103101JH)。
文摘The influences of the substituent base position on the excited state intramolecular proton transfer fluorescence properties were explored in 2-(2'-hydroxyphenyl)imidazo[1,2-a]-pyridine(HPIP)and HPIP's derivatives(5'Br-HPIP and 6'BrHPIP).And the density functional theory(DFT)and time-dependent DFT(TD-DFT)methods were used to calculate the molecule structures.The calculated results showed that the influence of 5'Br-HPIP on the fluorescence intensity is stronger than that of 6'Br-HPIP.The fluorescence emission peak of 5'Br-HPIP occurred a blue shift compared with HPIP,and 6'BrHPIP exhibited an opposite red shift.The change of the fluorescence emission peak was attributed to the decrease of the energy gap from 6'Br-HPIP to 5'Br-HPIP.Our work on the substituent position influence could be helpful to design and develop new materials.
基金supported by the Fundamental Research Funds for the Central Universities (CDJZR10220006)supports from the Key Laboratory of Functional Crystals and Laser Technology,TIPC,Chinese Academy of Sciences
文摘o-hydroxyphenyl-triazine derivatives with formyl substituents were surveyed for the excited state intramolecular proton transfer (ESIPT).The occurrence of ESIPT was confirmed by well-separated emission bands for the derivatives.A low energy change from enol to keto in the excited state explains ESIPT for the derivatives.
