We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonometh...We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.展开更多
为了考察石墨烯对硝基甲烷(NM)反应机理的影响,采用ONIOM(our Own N-layer Integrated molecular Orbital and molecular Mechanics)方法研究了硝基甲烷在石墨烯表面的三种初始反应,包括NM-亚硝酸甲酯(MN)重排反应、氢迁移重排反应及C—...为了考察石墨烯对硝基甲烷(NM)反应机理的影响,采用ONIOM(our Own N-layer Integrated molecular Orbital and molecular Mechanics)方法研究了硝基甲烷在石墨烯表面的三种初始反应,包括NM-亚硝酸甲酯(MN)重排反应、氢迁移重排反应及C—N键均裂反应。结果表明,石墨烯表面影响了NM初始反应过渡态、反应产物的结构及能量。与孤立NM相比,NM在石墨烯表面的三种初始反应活化能依次降低了13.4 k J·mol-1、增加了3.8 k J·mol-1和5.4 k J·mol-1,活化能的顺序由C—N键均裂反应<氢迁移重排反应<NM-MN重排反应变为NM-MN重排反应<C—N键均裂反应<氢迁移重排反应。由于石墨烯的平面结构,导致反应过渡态与反应产物的结构倾向于形成平面结构或重叠式构型,从而能够最大程度地与石墨烯相互作用。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574115 and 11704146)
文摘We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.
文摘为了考察石墨烯对硝基甲烷(NM)反应机理的影响,采用ONIOM(our Own N-layer Integrated molecular Orbital and molecular Mechanics)方法研究了硝基甲烷在石墨烯表面的三种初始反应,包括NM-亚硝酸甲酯(MN)重排反应、氢迁移重排反应及C—N键均裂反应。结果表明,石墨烯表面影响了NM初始反应过渡态、反应产物的结构及能量。与孤立NM相比,NM在石墨烯表面的三种初始反应活化能依次降低了13.4 k J·mol-1、增加了3.8 k J·mol-1和5.4 k J·mol-1,活化能的顺序由C—N键均裂反应<氢迁移重排反应<NM-MN重排反应变为NM-MN重排反应<C—N键均裂反应<氢迁移重排反应。由于石墨烯的平面结构,导致反应过渡态与反应产物的结构倾向于形成平面结构或重叠式构型,从而能够最大程度地与石墨烯相互作用。
