In this paper, we describe the variety defined by the twisted transfer ideal. It turns out that this variety is nothing but the union of reflecting hyperplanes and the fixed subspaces of the elements of order p in G.
The twisted intramolecular charge transfer and the excited state relaxation of 1-aminoanthraquinone (1-NH2-AQ) in different solvents are investigated using quantum chemical calculations in this paper. The geometries...The twisted intramolecular charge transfer and the excited state relaxation of 1-aminoanthraquinone (1-NH2-AQ) in different solvents are investigated using quantum chemical calculations in this paper. The geometries of the ground state are optimized both in gas and solvents based on the high-level ab initio calculations, the lowest excited singlet state geometry is optimized only in gas for simplicity. An intramolecular charge transfer property is substantiated by the large change of dipole moments between the So and S1 states. The mechanism of twisted intramolecular charge transfer is proposed by the conformational relaxation on the potential surface of the $1 state. Quantum chemical calculations present that internal conversion and intersystem crossing are important approaches to the ultrafast deactivation of the S~ state via the twisting of the amino group, The smaller energy difference between the So and S1 state shows that the internal conversion process is much faster in a polar solvent than in a nonpolar solvent. Energy intersections between the T2 and S1 state in cyclohexane and dioxane indicate a faster intersystem crossing process in them than in ethanol. These theoretical results agree well with the previous experimental results. Energy barriers are predicted on the potential surface of the S1 state, and they have a positive correlation to solvent viscosity, and the timescale of twisted intra-molecular charge transfer in dioxane is predicted to be longer than in cyclohexane and ethanol.展开更多
Polydimethylsilylenes bearing pyrenyl groups exhibit emissions fromtwisted intramolecular charge transfer state between the aromatic ring and thesilicon backbone both in polar and nonpolar solvents.
Inspired by the activity-based sensing method, the hydrazine-modified naphthalene derivative(Naph1) was synthesized and used as a fluorescent probe to detect formaldehyde(FA) in living cells. Through the condensation ...Inspired by the activity-based sensing method, the hydrazine-modified naphthalene derivative(Naph1) was synthesized and used as a fluorescent probe to detect formaldehyde(FA) in living cells. Through the condensation reaction between the probe Naph1 and analyte FA, researchers observed a ~14 folds enhancement of fluorescent signal around 510 nm in an experiment, realizing the high selectivity and sensitivity detection of FA. However, a theoretical understanding of the sensing mechanism was not provided in the experimental work. Given this, the light-up fluorescent detecting mechanism was in-depth unveiled by performing the time-dependent density functional theory(TDDFT) and the complete active space self-consistent field(CASSCF) theoretical calculations on excited-state intramolecular proton transfer(ESIPT)and non-adiabatic excited-state dynamics simulation. The deactivation channel of S_1/T_2 intersystem crossing(ISC) was turned off to successfully recognize FA. Insight into the ESIPT-based fluorescent detecting mechanism indicated that ESIPT was essential to light-up fluorescent probes. This work would provide a new viewpoint to develop ESIPT-based fluorescent probes for detecting reactive carbon species in vivo or vitio.展开更多
Though Olefin-linked covalent organic frameworks(oCOFs)possess excellentπ-electron delocalization,the barely reversible olefin linkage brings challenges for oCOFs’synthesis and functionalization.Here,we synthesize n...Though Olefin-linked covalent organic frameworks(oCOFs)possess excellentπ-electron delocalization,the barely reversible olefin linkage brings challenges for oCOFs’synthesis and functionalization.Here,we synthesize new oCOFs with tertiary amine knots which have twisted configuration and electron-donating nature.Investigation into the structural variation and photoelectric performance shows that the twisted configuration of oCOF-TFPA could favor to the intramolecular charge transfer process and reduce the pos-sibility of aggregation-caused quenching.Photoelectrical measurements and electric band structure cal-culation both verify the superiority of this oCOFs’structure in photoelectric sensing.展开更多
Comprehensive Summary Nanofluorophores based on aggregation-induced emission(AIE)dyes have recently received considerable attention because of their unique optical properties and biocompatibility.In this work,we repor...Comprehensive Summary Nanofluorophores based on aggregation-induced emission(AIE)dyes have recently received considerable attention because of their unique optical properties and biocompatibility.In this work,we report an emission-tunable nanofluorophore constructed by the self-assembly of an amphiphilic block copolymer(denoted by PTN).The diblock copolymer was synthesized by RAFT polymerization.A polyethylene glycol-based trithiocarbonate was employed as the macromolecular chain transfer agent,and a near-infrared emitting tetraphenylethylene derivative with a vinyl terminal group was designed as the monomer.The block copolymers self-assembled in an aqueous solution to form nanospheres,which showed near-infrared emission at approximately 720 nm with a significant Stokes shift of approximately 260 nm.Furthermore,nanofluorophores have excellent biocompatibility,photostability,and pH-independent emission-tunable properties,and were successfully applied to label HeLa cells for fluorescence imaging.展开更多
Inspired by nature’s molecular machines,the scientific research on solid-state molecular rotors is of great interest yet remains largely unexplored.Herein,we report a unique example of a thermal energydriven stimuli-...Inspired by nature’s molecular machines,the scientific research on solid-state molecular rotors is of great interest yet remains largely unexplored.Herein,we report a unique example of a thermal energydriven stimuli-responsive solid-state molecular rotor,which features an o-carborane moiety as a rotor that directly transduces the surrounding thermal energy into molecular rotations in the crystalline state.Its rotation is confirmed by X-ray diffraction.展开更多
文摘In this paper, we describe the variety defined by the twisted transfer ideal. It turns out that this variety is nothing but the union of reflecting hyperplanes and the fixed subspaces of the elements of order p in G.
基金Project supported by the Program of Outstanding Innovation Team of Hubei Normal University,China(Grant No.T201502)the Natural Science Foundation of Hubei Province,China(Grant Nos.2014CFB349 and 2016CFC742)the National Natural Science Foundation of China(Grant No.11674355)
文摘The twisted intramolecular charge transfer and the excited state relaxation of 1-aminoanthraquinone (1-NH2-AQ) in different solvents are investigated using quantum chemical calculations in this paper. The geometries of the ground state are optimized both in gas and solvents based on the high-level ab initio calculations, the lowest excited singlet state geometry is optimized only in gas for simplicity. An intramolecular charge transfer property is substantiated by the large change of dipole moments between the So and S1 states. The mechanism of twisted intramolecular charge transfer is proposed by the conformational relaxation on the potential surface of the $1 state. Quantum chemical calculations present that internal conversion and intersystem crossing are important approaches to the ultrafast deactivation of the S~ state via the twisting of the amino group, The smaller energy difference between the So and S1 state shows that the internal conversion process is much faster in a polar solvent than in a nonpolar solvent. Energy intersections between the T2 and S1 state in cyclohexane and dioxane indicate a faster intersystem crossing process in them than in ethanol. These theoretical results agree well with the previous experimental results. Energy barriers are predicted on the potential surface of the S1 state, and they have a positive correlation to solvent viscosity, and the timescale of twisted intra-molecular charge transfer in dioxane is predicted to be longer than in cyclohexane and ethanol.
文摘Polydimethylsilylenes bearing pyrenyl groups exhibit emissions fromtwisted intramolecular charge transfer state between the aromatic ring and thesilicon backbone both in polar and nonpolar solvents.
基金the National Natural Science Foundation of China (Grant No. 12104392)the Natural Science Foundation of Hebei Province, China (Grant No. B2021203017)+1 种基金the High-Level Innovative Talents Program of Shenyang City (Grant No. RC200565)the Innovation Capability Improvement Project of Hebei Province, China (Grant No. 22567605H)。
文摘Inspired by the activity-based sensing method, the hydrazine-modified naphthalene derivative(Naph1) was synthesized and used as a fluorescent probe to detect formaldehyde(FA) in living cells. Through the condensation reaction between the probe Naph1 and analyte FA, researchers observed a ~14 folds enhancement of fluorescent signal around 510 nm in an experiment, realizing the high selectivity and sensitivity detection of FA. However, a theoretical understanding of the sensing mechanism was not provided in the experimental work. Given this, the light-up fluorescent detecting mechanism was in-depth unveiled by performing the time-dependent density functional theory(TDDFT) and the complete active space self-consistent field(CASSCF) theoretical calculations on excited-state intramolecular proton transfer(ESIPT)and non-adiabatic excited-state dynamics simulation. The deactivation channel of S_1/T_2 intersystem crossing(ISC) was turned off to successfully recognize FA. Insight into the ESIPT-based fluorescent detecting mechanism indicated that ESIPT was essential to light-up fluorescent probes. This work would provide a new viewpoint to develop ESIPT-based fluorescent probes for detecting reactive carbon species in vivo or vitio.
基金supported by the National Key R&D Program of China(Nos.2021YFE0201400,2018YFA0703200,2020YFA0308800)National Natural Science Foundation of China(Nos.51773041,61890940,21603038,11974045)Shanghai Com-mittee of Science and Technology in China(No.18ZR1404900).
文摘Though Olefin-linked covalent organic frameworks(oCOFs)possess excellentπ-electron delocalization,the barely reversible olefin linkage brings challenges for oCOFs’synthesis and functionalization.Here,we synthesize new oCOFs with tertiary amine knots which have twisted configuration and electron-donating nature.Investigation into the structural variation and photoelectric performance shows that the twisted configuration of oCOF-TFPA could favor to the intramolecular charge transfer process and reduce the pos-sibility of aggregation-caused quenching.Photoelectrical measurements and electric band structure cal-culation both verify the superiority of this oCOFs’structure in photoelectric sensing.
基金the National Natural Science Foundation of China(21674075)the Natural Science Foundation of Jiangsu Province(BK20161211)the Key University Science Research Project of Jiangsu Province(17KJA150007)。
文摘Comprehensive Summary Nanofluorophores based on aggregation-induced emission(AIE)dyes have recently received considerable attention because of their unique optical properties and biocompatibility.In this work,we report an emission-tunable nanofluorophore constructed by the self-assembly of an amphiphilic block copolymer(denoted by PTN).The diblock copolymer was synthesized by RAFT polymerization.A polyethylene glycol-based trithiocarbonate was employed as the macromolecular chain transfer agent,and a near-infrared emitting tetraphenylethylene derivative with a vinyl terminal group was designed as the monomer.The block copolymers self-assembled in an aqueous solution to form nanospheres,which showed near-infrared emission at approximately 720 nm with a significant Stokes shift of approximately 260 nm.Furthermore,nanofluorophores have excellent biocompatibility,photostability,and pH-independent emission-tunable properties,and were successfully applied to label HeLa cells for fluorescence imaging.
基金support from National Natural Science Foundation of China(nos.21975130,21835003,21404059,21674050,91833304,and 21422402)the National Basic Research Program of China(nos.2017 YFB0404501 and 2014CB648300)+7 种基金the Natural Science Foundation of Jiangsu Province(no.BE2019120)the Six Talent Peaks Project of Jiangsu Province(no.TDXCL-009)the 333 Project of Jiangsu Province(no.BRA2017402)the Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of Chinathe Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions(no.TJ217038)Scientific Research Foundation of Nanjing University of Posts&Telecommunications(no.NY219060)the Fundamental Research Funds for the Central Universitiesthe open research fund of Key Laboratory of MEMS of Ministry of Education,Southeast University and the Big Data Center of Southeast University.
文摘Inspired by nature’s molecular machines,the scientific research on solid-state molecular rotors is of great interest yet remains largely unexplored.Herein,we report a unique example of a thermal energydriven stimuli-responsive solid-state molecular rotor,which features an o-carborane moiety as a rotor that directly transduces the surrounding thermal energy into molecular rotations in the crystalline state.Its rotation is confirmed by X-ray diffraction.