The high accuracy ab initio calculation method of multi-reference configuration interaction(MRCI) is used to compute the low-lying eight electronic states of CuN.The potential energy curves(PECs) of the X;∑;,1;Π...The high accuracy ab initio calculation method of multi-reference configuration interaction(MRCI) is used to compute the low-lying eight electronic states of CuN.The potential energy curves(PECs) of the X;∑;,1;Π,2;∑;,1;△,1;△,1;∑;,1;Π,and;∑;in a range of R=0.1 nm-0.5 nm are obtained and they are goodly asymptotes to the Cu(;S;) + N(;S;) and Cu(;S;)+N(;D;) dissociation limits.All the possible vibrational levels,rotational constants,and spectral constants for the six bound states of X;∑;,1;Π,2;∑;,1;△,1;∑;,and 1;Π are obtained by solving the radial Schrdinger equation of nuclear motion with the Le Roy provided Level 8.0 program.Also the transition dipole moments from the ground state X;∑;to the excited states 1;Π and 2;∑;are calculated and the result indicates that the 2;∑-X;∑ transition has a much higher transition dipole moment than the 1;Π-X;∑;transition even though the l;Π state is much lower in energy than the 2;∑;state.展开更多
The present paper covers ab initio UHF calculations with a d, p-polarized basis set performed for eight electronic states of BH2 and the equilibrium geometries, electronic term values Tc and vibrational frequencies of...The present paper covers ab initio UHF calculations with a d, p-polarized basis set performed for eight electronic states of BH2 and the equilibrium geometries, electronic term values Tc and vibrational frequencies of the five stable states X2A1, 2B1, 2B2, 22A1 and 2A2. On the basis of the UHF results, the states 22B2. 2B1 and 32A1 are predicted to be unstable. The MP2/6-31G * * calculations were performed for the X2A1 and 2B1, states, and the calculated equilibrium geometries, Tc value and vibrational frequencies are similar to the UHF results. The MP2/6-31G * * studies on the reaction BH2→BH + H for the X2A1 and 2B1 states were carried out and the HB-H bond energies of these two states were calculated.展开更多
The algebraic energy method (AEM) is applied to the study of molecular dissociation energy De for 11 heteronuclear diatomic electronic states: a^3∑+ state of NaK, X^2∑+ state of XeBr, X^2∑+ state of HgI, X^1...The algebraic energy method (AEM) is applied to the study of molecular dissociation energy De for 11 heteronuclear diatomic electronic states: a^3∑+ state of NaK, X^2∑+ state of XeBr, X^2∑+ state of HgI, X^1∑+ state of LiH, A3∏(1) state of IC1, X^1∑+ state of CsH, A(3∏1) and B0+(3∏) states of CIF, 21∏ state of KRb, X^1∑+ state of CO, and c^3∑+ state of NaK molecule. The results show that the values of De computed by using the AEM are satisfactorily accurate compared with experimental ones. The AEM can serve as an economic and useful tool to generate a reliable De within an allowed experimental error for the electronic states whose molecular dissociation energies are unavailable from the existing literature展开更多
The investigation of electronic excited states in single-molecule junctions not only provides platforms to reveal the photophysical and photochemical processes at the molecular level,but also brings opportunities for ...The investigation of electronic excited states in single-molecule junctions not only provides platforms to reveal the photophysical and photochemical processes at the molecular level,but also brings opportunities for the development of single-molecule optoelectronic devices.Understanding the interaction mechanisms between molecules and nanocavities is essential to obtain ondemand properties in devices by artificial design,since molecules in junctions exhibit unique behaviors of excited states benefited from the structures of metallic nanocavities.Here,we review the excitation mechanisms involved in the interplay between molecules and plasmonic nanocavities,and reveal the influence of nanostructures on excited-state properties by demonstrating the differences in excited state decay processes.Furthermore,vibronic transitions of molecules between nanoelectrodes are also discussed,offering a new single-molecule characterization method.Finally,we provide the potential applications and challenges in single-molecule optoelectronic devices and the possible directions in exploring the underlying mechanisms of photophysical and photochemical processes.展开更多
Luminogens with aggregation-induced emission(AIE)characteristics(or AIEgens)have been widely used in various applications due to their excellent luminescent properties in molecular aggregates and the solid state.A dee...Luminogens with aggregation-induced emission(AIE)characteristics(or AIEgens)have been widely used in various applications due to their excellent luminescent properties in molecular aggregates and the solid state.A deep understanding of the AIE mechanism is critical for the rational development of AIEgens.In this work,the“state-crossing from a locally excited to an electron transfer state”(SLEET)model is employed to rationalize the AIE phenomenon of two(bi)piperidylanthracenes.According to the SLEET model,an electron transfer(ET)state is formed along with the rotation of the piperidyl group in the excited state of(bi)piperidylan-thracene monomers,leading to fluorescence quenching.In contrast,a bright state exists in the crystal and molecular aggregates of these compounds,as the intermolecular interactions restrict the formation of the dark ET state.This mechanistic understanding could inspire the deployment of the SLEET model in the rational designs of various functional AIEgens.展开更多
We made an extended study on the structure and properties of the low-lying electronic states of ethynyl substituted aniline and their cations. We performed these calculations using density functional theory method(B3...We made an extended study on the structure and properties of the low-lying electronic states of ethynyl substituted aniline and their cations. We performed these calculations using density functional theory method(B3LYP and CAM-B3LYP DFT) and the complete active space self-consistent field(CASSCF) approach in connection with the aug-cc-pVZ Dunning's basis sets and concerted ANO-L-VDZP basis sets. Our results included their equilibrium geometries, the vertical excitation spectra and the vertical and adiabatic ionization energies. The effect of ethynyl substitution on the electronic structure and the spectroscopy of aniline was probed.展开更多
文摘The high accuracy ab initio calculation method of multi-reference configuration interaction(MRCI) is used to compute the low-lying eight electronic states of CuN.The potential energy curves(PECs) of the X;∑;,1;Π,2;∑;,1;△,1;△,1;∑;,1;Π,and;∑;in a range of R=0.1 nm-0.5 nm are obtained and they are goodly asymptotes to the Cu(;S;) + N(;S;) and Cu(;S;)+N(;D;) dissociation limits.All the possible vibrational levels,rotational constants,and spectral constants for the six bound states of X;∑;,1;Π,2;∑;,1;△,1;∑;,and 1;Π are obtained by solving the radial Schrdinger equation of nuclear motion with the Le Roy provided Level 8.0 program.Also the transition dipole moments from the ground state X;∑;to the excited states 1;Π and 2;∑;are calculated and the result indicates that the 2;∑-X;∑ transition has a much higher transition dipole moment than the 1;Π-X;∑;transition even though the l;Π state is much lower in energy than the 2;∑;state.
基金Supported by the National Natural Science Foundation of China
文摘The present paper covers ab initio UHF calculations with a d, p-polarized basis set performed for eight electronic states of BH2 and the equilibrium geometries, electronic term values Tc and vibrational frequencies of the five stable states X2A1, 2B1, 2B2, 22A1 and 2A2. On the basis of the UHF results, the states 22B2. 2B1 and 32A1 are predicted to be unstable. The MP2/6-31G * * calculations were performed for the X2A1 and 2B1, states, and the calculated equilibrium geometries, Tc value and vibrational frequencies are similar to the UHF results. The MP2/6-31G * * studies on the reaction BH2→BH + H for the X2A1 and 2B1 states were carried out and the HB-H bond energies of these two states were calculated.
基金Project supported by the Science Foundation of China West Normal University (Grant No 05B016) and the Science Foundation of Sichuan province Educational Bureau of China (Grant No 2006A080).
文摘The algebraic energy method (AEM) is applied to the study of molecular dissociation energy De for 11 heteronuclear diatomic electronic states: a^3∑+ state of NaK, X^2∑+ state of XeBr, X^2∑+ state of HgI, X^1∑+ state of LiH, A3∏(1) state of IC1, X^1∑+ state of CsH, A(3∏1) and B0+(3∏) states of CIF, 21∏ state of KRb, X^1∑+ state of CO, and c^3∑+ state of NaK molecule. The results show that the values of De computed by using the AEM are satisfactorily accurate compared with experimental ones. The AEM can serve as an economic and useful tool to generate a reliable De within an allowed experimental error for the electronic states whose molecular dissociation energies are unavailable from the existing literature
基金supported by the National Natural ScienceFoundation of China (Nos. 22173075, 21933012 and 31871877)the National Key R&D Program of China (No. 2017YFA0204902)+1 种基金the Fundamental Research Funds for the Central Universities(Nos. 20720200068 and 20720190002)the Beijing NationalLaboratory for Molecular Sciences (No. BNLMS202005).
文摘The investigation of electronic excited states in single-molecule junctions not only provides platforms to reveal the photophysical and photochemical processes at the molecular level,but also brings opportunities for the development of single-molecule optoelectronic devices.Understanding the interaction mechanisms between molecules and nanocavities is essential to obtain ondemand properties in devices by artificial design,since molecules in junctions exhibit unique behaviors of excited states benefited from the structures of metallic nanocavities.Here,we review the excitation mechanisms involved in the interplay between molecules and plasmonic nanocavities,and reveal the influence of nanostructures on excited-state properties by demonstrating the differences in excited state decay processes.Furthermore,vibronic transitions of molecules between nanoelectrodes are also discussed,offering a new single-molecule characterization method.Finally,we provide the potential applications and challenges in single-molecule optoelectronic devices and the possible directions in exploring the underlying mechanisms of photophysical and photochemical processes.
基金This work was supported by A^(*)STAR under Its Advanced Manufacturing and Engineering Program of Singapore(No.A2083c0051).
文摘Luminogens with aggregation-induced emission(AIE)characteristics(or AIEgens)have been widely used in various applications due to their excellent luminescent properties in molecular aggregates and the solid state.A deep understanding of the AIE mechanism is critical for the rational development of AIEgens.In this work,the“state-crossing from a locally excited to an electron transfer state”(SLEET)model is employed to rationalize the AIE phenomenon of two(bi)piperidylanthracenes.According to the SLEET model,an electron transfer(ET)state is formed along with the rotation of the piperidyl group in the excited state of(bi)piperidylan-thracene monomers,leading to fluorescence quenching.In contrast,a bright state exists in the crystal and molecular aggregates of these compounds,as the intermolecular interactions restrict the formation of the dark ET state.This mechanistic understanding could inspire the deployment of the SLEET model in the rational designs of various functional AIEgens.
基金Supported by the National Natural Science Foundation of China(No.21173096) and the National Basic Research Program of China(No. 2013CB83480).
文摘We made an extended study on the structure and properties of the low-lying electronic states of ethynyl substituted aniline and their cations. We performed these calculations using density functional theory method(B3LYP and CAM-B3LYP DFT) and the complete active space self-consistent field(CASSCF) approach in connection with the aug-cc-pVZ Dunning's basis sets and concerted ANO-L-VDZP basis sets. Our results included their equilibrium geometries, the vertical excitation spectra and the vertical and adiabatic ionization energies. The effect of ethynyl substitution on the electronic structure and the spectroscopy of aniline was probed.