Azulene-fused acenes demonstrate enhanced stability,unique aromaticity,and distinctive photophysical properties,rendering them significant in organic electronics.In the present study,we report a new type of nonalterna...Azulene-fused acenes demonstrate enhanced stability,unique aromaticity,and distinctive photophysical properties,rendering them significant in organic electronics.In the present study,we report a new type of nonalternant analogue of pentacene incorporating a non-terminal azulene unit.Aromaticity analyses reveal that the five-membered rings in this analogue exhibit antiaromatic.The extensive conjugated aryl substituents on the acene’s side shift the HOMO distributions from the naphthyl ring and metallacycle to the aryl groups,thereby narrowing the HOMO-LUMO energy gap and enhancing absorptions in the low-energy regions.Furthermore,these fused acenes readily react with base rather than acid,resulting in reversible base/acid stimuli responsiveness.展开更多
Design and synthesis of new organic functional materials with improved performance or novel properties are of great importance in the field of optoelectronics.Azulene,as a non-alternant aromatic hydrocarbon,has attrac...Design and synthesis of new organic functional materials with improved performance or novel properties are of great importance in the field of optoelectronics.Azulene,as a non-alternant aromatic hydrocarbon,has attracted rising attention in the last few years.Different from most common aromatic hydrocarbons,azulene has unique characteristics,including large dipole moment,small gap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO）.However,the design and synthesis of azulene-based functional materials are still facing several challenges.This review focuses on the recent development of organic functional materials employing azulene unit.The synthesis of various functionalized azulene derivatives is summarized and their applications in optoelectronics are discussed,with particular attention to the fields including nonlinear optics（NLO）,organic field-effect transistors（OFETs）,solar cells,and molecular devices.展开更多
Azulene,an isomer of naphthalene,has become one of hot chemical structures in the research field of functional materials,due to its anti-Kasha's rule emissions and unusual physicochemical properties(e.g.,photophys...Azulene,an isomer of naphthalene,has become one of hot chemical structures in the research field of functional materials,due to its anti-Kasha's rule emissions and unusual physicochemical properties(e.g.,photophysical,electrochemical,and photoelectrochemical properties).In the past,the synthesis of azulene-based compounds is relatively inconvenient.Recently,there have been more and more reports about the synthesis strategies of the azulene-based compounds for finely tuning the physicochemical properties.In this article,we introduce several synthetic methods for kinds of azulene-based compounds which has unusual physicochemical properties.With these convenient methods and unique physicochemical properties,azulene-based compounds can be applied into many fields such as specific bioimaging,advanced molecular switches,organic field-effect transistor(OFET),organic light emitting diode(OLED),solar cells,and so forth.And these properties are also summarized here.展开更多
In the^(1)H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus,two new azulene-type sesquiterpenoids,7-isopropenyl-4-methyl-azulene-1-carboxylic acid(1)and 15-hydroxy-3,6-dihydrolactar...In the^(1)H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus,two new azulene-type sesquiterpenoids,7-isopropenyl-4-methyl-azulene-1-carboxylic acid(1)and 15-hydroxy-3,6-dihydrolactarazulene(2),together with seven known compounds were characterized.Their structures were determined on basis of spectroscopic evidence,as well as by comparing with literature data.Amongst the known metabolites,the^(13)C NMR assignment of 15-hydroxy-6,7-dihydrolactarazulene(3)is reported here for the first time.Moreover,7-acetyl-4-methylazulene-1-carbaldehyde(5)displayed a moderate antibacterial activity against Staphylococcus aureus.展开更多
Azulene is a promising building block for creating innovative polycyclic aromatic hydrocarbons. This study involved the construction of three nonalternant isomers of pentacene by fusing two azulene units, named Az-PH1...Azulene is a promising building block for creating innovative polycyclic aromatic hydrocarbons. This study involved the construction of three nonalternant isomers of pentacene by fusing two azulene units, named Az-PH1/2/3. Az-PH1 was initially developed through the rhodium(Ⅱ)-catalyzed cyclization of bis(N-tosylhydrazone)s. Intriguingly, Az-PH1 was also unexpectedly obtained during a nickel(0)-catalyzed one-step tandem reaction. We investigated the optical and electrochemical properties, aromaticity, and photo-oxidative stability of Az-PH1, comparing it with the well-known pentacene using density functional theory, electrochemical, and photophysical tests. Our results showed that the azulene-fusing strategy resulted in a molecule with narrow optical bandgaps(2.046 eV) and a long half-life time under ambient air conditions.展开更多
The electronic structures, one-photon absorption （OPA） and two-photon absorption （TPA） properties of the azulenylporphyrins and azulene-fused porphyrins have been comparatively studied by using DFT/B3LYP/6-31G（d...The electronic structures, one-photon absorption （OPA） and two-photon absorption （TPA） properties of the azulenylporphyrins and azulene-fused porphyrins have been comparatively studied by using DFT/B3LYP/6-31G（d） and the ZINDO/SDCI method. With the number of azulenyl groups increasing, the OPA wavelengths of all molecules are red-shifted in 400-600 nm and the two-photon absorption cross section is gradually enlarged. The azulene-fused structures facilitate an expanding conjugated area and increasing TPA cross section. The origin of TPA properties of studied compounds is studied with a two-level model. In summary, the azulene-fused porphyrins exhibit strong two-photon absorption.展开更多
We previously isolated a natural product, namely guaiazulene-2,9-dione showing strong antibacterial activity against Vibrio anguillarum, from a gorgonian Muriceides collaris collected in South China Sea. In this exper...We previously isolated a natural product, namely guaiazulene-2,9-dione showing strong antibacterial activity against Vibrio anguillarum, from a gorgonian Muriceides collaris collected in South China Sea. In this experiment, guaiazulene-2,9-dione was quantitatively synthesized with an optimized one-step bromine oxidation method using guaiazulene as the raw material. The key reaction condition including reaction time and temperature, drop rate of bromine, concentration of aqueous THF solution, respective molar ratio of guaiazulene to bromine and acetic acid, and concentration of guaiazulene in aqueous THF solution, were investigated individually at five levels each for optimization. Combined with the verification test to show the absolute yield of each optimization step, the final optimal condition was determined as: when a solution of 0.025 mmol m L-1 guaiazulene in 80% aqueous THF was treated with four volumes of bromine at a drop rate of 0.1 m L min-1 and four volumes of acetic acid at-5℃ for three hours, the yield of guaiazulene-2,9-dione was 23.72%. This was the first report concerning optimized one-step synthesis to provide a convenient method for the large preparation of guaiazulene-2,9-dione.展开更多
A simple and efficient procedure was developed for the synthesis of 11H（2H）-4-oxothiophene[3＇,4＇：6,5]pyrido[3,2-a]azulene-10-carboxylates（3） in moderate to good yields via the Gewald reaction of ethyl 1-cyanoac...A simple and efficient procedure was developed for the synthesis of 11H（2H）-4-oxothiophene[3＇,4＇：6,5]pyrido[3,2-a]azulene-10-carboxylates（3） in moderate to good yields via the Gewald reaction of ethyl 1-cyanoacetyl-2-methoxyazulene-3-carboxylate（1） with carbonyl compounds（2） and elemental sulfur utilizing imidazole as catalyst.This reaction provides a new procedure for synthesis of pyridinone-fused azulenes.展开更多
In the study, the X-H （X=CH2, NH, O） bond dissociation energies （BDE） of para-substituted azulene （Y-C10H8X-H） were predicted theoretically for the first time using Density Functronal Theory （DFT） methods at U...In the study, the X-H （X=CH2, NH, O） bond dissociation energies （BDE） of para-substituted azulene （Y-C10H8X-H） were predicted theoretically for the first time using Density Functronal Theory （DFT） methods at UB3LYP/6-311 ＋ ＋g（2df,2p）//UB3LYP/6-31 ＋g（d） level. It was found that the substituents exerted similar effects on the X-H BDE of azulene as those on benzene, except for 6-substituted 2-methylazulene. Owing to the substituent-dipole interaction, the reaction constants （ρ^＋） of 2- and 6-Y-CIoHsX-H （X=NH and O only） varied violently. The origin of the substituent effects on the X-H BDE of azulene was found, by both GE/RE and SIE theory, to be directly associated with variation of the radical effects, although the ground effects also played a modest role in determining the net. substituent effects.展开更多
We describe the synthesis and evaluation of an azulene-based chemodosimeter for nitrite.The probe was found to undergo two distinct color changes upon introduction of aqueous nitrite ion.A near-instant formation of a ...We describe the synthesis and evaluation of an azulene-based chemodosimeter for nitrite.The probe was found to undergo two distinct color changes upon introduction of aqueous nitrite ion.A near-instant formation of a grey color provides a qualitative indication of the presence of nitrite,followed by the formation of a deep-yellow/orange color,the endpoint from which quantitative data can be derived.The azulene probe exhibits 1:1 stoichiometry of reaction with nitrite in water,and is selective for nitrite over other anions.The azulene probe was applied to determine nitrite content in cured meat,and compared with the British Standard testing procedure(Griess test).The value obtained from the azulene-based probe agreed closely with the standard test.Our procedure only requires the preparation of one standard solution,instead of the three required for the standard Griess test.展开更多
Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo anal...Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo analogue, is designed and synthesized, which has a twisted molecular backbone and R/Sisomers in single crystals. Interestingly, Az II shows the characteristics of both isoindigo and azulene,such as reversible redox behavior and reversible proton responsiveness. UV-vis-NIR,^(1)H NMR and electron paramagnetic resonance(EPR) measurements were carried out to get insights into the possible mechanism of the proton-responsive property of Az II. The results demonstrated that only one azulenyl moiety of molecule of Az II was protonated and deprotonated, and the protonated Az II can be further oxidized to form azulenium cation radicals.展开更多
The study was designed to investigate the anti-inflammatory and composition of essential oil of two plant family Asteraceae, Achillea fragrantissima and Lactuca serriola growing under dry desert condition. The anti-in...The study was designed to investigate the anti-inflammatory and composition of essential oil of two plant family Asteraceae, Achillea fragrantissima and Lactuca serriola growing under dry desert condition. The anti-inflammatory effect of volatile oil extracted by hydrodistillation of plants was studied using carrageenan induced paw edema. Essential oil （100 mg/kg） and （200 mg/kg） were tested the two plant show high inhibition after 4 h, concentration （200 mg/kg） show high inhibition than （100 mg/kg） after 4 h. Sesqui sabinene hydrate, Azuline and u-Bisabolol are the main constituents of the volatile oil were investigated by capillary GC （gas chromatography） and GC-MS （gas chromatography-mass spectrometry）. The discussion shows the role of chemical compound azulene in inflammatory inhibition.展开更多
Comprehensive Summary Open-shell graphene fragments(OGFs)with non-benzenoid topologies are attracting increasing attention due to their potential applications in organic light-emitting diodes(OLEDs)and organic radical...Comprehensive Summary Open-shell graphene fragments(OGFs)with non-benzenoid topologies are attracting increasing attention due to their potential applications in organic light-emitting diodes(OLEDs)and organic radical conductors.Herein,we report the synthesis of an air-stable fluorenyl radical derivative(AR1)containing a seven-membered ring,achieving thermodynamic stabilization through the fusion of a naphthalene ring around its periphery and anthracene substituent.展开更多
The aggregation state modification of graphene,including nanographene molecules,is essential for optimizing their performance in various applications.However,the current understanding of how to regulate the structures...The aggregation state modification of graphene,including nanographene molecules,is essential for optimizing their performance in various applications.However,the current understanding of how to regulate the structures and features of nanographene aggregates primarily relies on non-covalent bonding interactions,while achieving exact control remains a significant challenge.Herein,we describe unique occurrence in which aσ-bond is reversibly constructed and subsequently broken to produce dimeric nanographene and monomeric analogues.These molecules are fused with azulene unit(s)at the edge.The acid-driven transformation occurs with a radical mechanism.Moreover,the manipulation of the chemical employed to terminate the reaction can regulate the selective creation of dimer and monomer.As compared to the monomer,the dimer with a helical structure exhibited a substantial rise in the molar absorbance coefficient(ɛ),fluorescence emission,a greater range of electrochemical characteristics,and much enhanced chirality stability.This study presents an unprecedented strategy that can precisely control and modulate the structures of aggregation state and characteristics of nanographene by regulating covalent bond cleavage and formation.展开更多
The molecular first hyperpolarizabilities (β) and electronic properties of some azulenic retinal analogues and their derivatives have been investigated theoretically by employing semiempirical approaches. The results...The molecular first hyperpolarizabilities (β) and electronic properties of some azulenic retinal analogues and their derivatives have been investigated theoretically by employing semiempirical approaches. The results indicate that the protonated Schiff bases (PSB) of the 2-substituted azulenic retinal analogues possess extremely large negative β values and very good transparency. These can be attributed to the large difference between the ground state dipole moment and the first excited state dipole moment according to the electronic property analysis. The characteristic blue-shifted absorption in polar solvents of the 2-substituted PSB chromophores can be well explained by the negative solva-tochromic effects. The largest calculated |μβ| value can reach the magnitude of 10-44 esu, which is close to the highest reported values of synthesized chromophores.展开更多
The first hyperpolarizabilities of a series of novel azulenic-barbituric acid chromophores have been studied by using 12 excitation wavelengths, ranging from 900 to 1907 nm. The dispersion relation of the first hyperp...The first hyperpolarizabilities of a series of novel azulenic-barbituric acid chromophores have been studied by using 12 excitation wavelengths, ranging from 900 to 1907 nm. The dispersion relation of the first hyperpolariza-bilities of chromophores holds the same tendency as the experimental results. In addition, the static first hyperpo-larizability 0 of molecules was calculated by means of the Sum-Over-States (SOS) expression and the two-level formula respectively. The results show that these molecules possess large static first hyperpolarizabilities and the 0 value increases as the donor or acceptor strength enhances; the distorted degree of molecules has also an important influence on the 0 value.展开更多
Main observation and conclusion By combination of two special structural units,a boron-nitrogen-fused polycyclic aromatic hydrocarbon and azulene with strong intramolecular dipoles,a novel BN aromatics,BN-Az,has been ...Main observation and conclusion By combination of two special structural units,a boron-nitrogen-fused polycyclic aromatic hydrocarbon and azulene with strong intramolecular dipoles,a novel BN aromatics,BN-Az,has been designed and synthesized with unique characteristics.The structure,optical and electrochemical properties,as well as charge transport property of BN-Az have been investigated.Notably,BN-Az selectively responds to fluoride ions and protons with a significant color change,which could also be monitored by NMR spectra and single-crystal X-ray analysis,indicating its potential as an effective ion sensing material in stimuli-responsive electronic devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.92156021,22350009,and 22101115)Financial Support for Outstanding Talents Training Fund in Shenzhen,the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)+2 种基金high level of special funds(No.G03050K003)Introduction of Major Talent Projects in Guangdong Province(No.2019CX01C079)supported by the Center for Computational Science and Engineering at SUSTech.
文摘Azulene-fused acenes demonstrate enhanced stability,unique aromaticity,and distinctive photophysical properties,rendering them significant in organic electronics.In the present study,we report a new type of nonalternant analogue of pentacene incorporating a non-terminal azulene unit.Aromaticity analyses reveal that the five-membered rings in this analogue exhibit antiaromatic.The extensive conjugated aryl substituents on the acene’s side shift the HOMO distributions from the naphthyl ring and metallacycle to the aryl groups,thereby narrowing the HOMO-LUMO energy gap and enhancing absorptions in the low-energy regions.Furthermore,these fused acenes readily react with base rather than acid,resulting in reversible base/acid stimuli responsiveness.
基金supported by National Basic Research Program of China(973 Program,No.2012CB933102)National Natural Science Foundation of China(Nos.51525303,21233001,21190034)the Fundamental Research Funds for the Central Universities and 111 Project
文摘Design and synthesis of new organic functional materials with improved performance or novel properties are of great importance in the field of optoelectronics.Azulene,as a non-alternant aromatic hydrocarbon,has attracted rising attention in the last few years.Different from most common aromatic hydrocarbons,azulene has unique characteristics,including large dipole moment,small gap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO）.However,the design and synthesis of azulene-based functional materials are still facing several challenges.This review focuses on the recent development of organic functional materials employing azulene unit.The synthesis of various functionalized azulene derivatives is summarized and their applications in optoelectronics are discussed,with particular attention to the fields including nonlinear optics（NLO）,organic field-effect transistors（OFETs）,solar cells,and molecular devices.
基金supported by the National Natural Science Foundation of China(No.21644005)National Program for Thousand Young Talents of China
文摘Azulene,an isomer of naphthalene,has become one of hot chemical structures in the research field of functional materials,due to its anti-Kasha's rule emissions and unusual physicochemical properties(e.g.,photophysical,electrochemical,and photoelectrochemical properties).In the past,the synthesis of azulene-based compounds is relatively inconvenient.Recently,there have been more and more reports about the synthesis strategies of the azulene-based compounds for finely tuning the physicochemical properties.In this article,we introduce several synthetic methods for kinds of azulene-based compounds which has unusual physicochemical properties.With these convenient methods and unique physicochemical properties,azulene-based compounds can be applied into many fields such as specific bioimaging,advanced molecular switches,organic field-effect transistor(OFET),organic light emitting diode(OLED),solar cells,and so forth.And these properties are also summarized here.
基金the Natural Science Foundation for a Chinese Government Scholarship Fund for Study Abroad(31470414,20140101126JC).
文摘In the^(1)H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus,two new azulene-type sesquiterpenoids,7-isopropenyl-4-methyl-azulene-1-carboxylic acid(1)and 15-hydroxy-3,6-dihydrolactarazulene(2),together with seven known compounds were characterized.Their structures were determined on basis of spectroscopic evidence,as well as by comparing with literature data.Amongst the known metabolites,the^(13)C NMR assignment of 15-hydroxy-6,7-dihydrolactarazulene(3)is reported here for the first time.Moreover,7-acetyl-4-methylazulene-1-carbaldehyde(5)displayed a moderate antibacterial activity against Staphylococcus aureus.
基金financially supported by the National Natural Science Foundation of China(No.22101170).
文摘Azulene is a promising building block for creating innovative polycyclic aromatic hydrocarbons. This study involved the construction of three nonalternant isomers of pentacene by fusing two azulene units, named Az-PH1/2/3. Az-PH1 was initially developed through the rhodium(Ⅱ)-catalyzed cyclization of bis(N-tosylhydrazone)s. Intriguingly, Az-PH1 was also unexpectedly obtained during a nickel(0)-catalyzed one-step tandem reaction. We investigated the optical and electrochemical properties, aromaticity, and photo-oxidative stability of Az-PH1, comparing it with the well-known pentacene using density functional theory, electrochemical, and photophysical tests. Our results showed that the azulene-fusing strategy resulted in a molecule with narrow optical bandgaps(2.046 eV) and a long half-life time under ambient air conditions.
基金Project supported by the National Natural Science Foundation of China the Open Project of State Key Laboratory of Supramolecular Structure and Materials of Jilin University (Grant No SKLSSM200716)
文摘The electronic structures, one-photon absorption （OPA） and two-photon absorption （TPA） properties of the azulenylporphyrins and azulene-fused porphyrins have been comparatively studied by using DFT/B3LYP/6-31G（d） and the ZINDO/SDCI method. With the number of azulenyl groups increasing, the OPA wavelengths of all molecules are red-shifted in 400-600 nm and the two-photon absorption cross section is gradually enlarged. The azulene-fused structures facilitate an expanding conjugated area and increasing TPA cross section. The origin of TPA properties of studied compounds is studied with a two-level model. In summary, the azulene-fused porphyrins exhibit strong two-photon absorption.
基金supported by National Natural Science Foundation of China (No. 21102136)Changjiang Scholars and Innovative Research Team in University (PCSIRT,No. IRT0944)
文摘We previously isolated a natural product, namely guaiazulene-2,9-dione showing strong antibacterial activity against Vibrio anguillarum, from a gorgonian Muriceides collaris collected in South China Sea. In this experiment, guaiazulene-2,9-dione was quantitatively synthesized with an optimized one-step bromine oxidation method using guaiazulene as the raw material. The key reaction condition including reaction time and temperature, drop rate of bromine, concentration of aqueous THF solution, respective molar ratio of guaiazulene to bromine and acetic acid, and concentration of guaiazulene in aqueous THF solution, were investigated individually at five levels each for optimization. Combined with the verification test to show the absolute yield of each optimization step, the final optimal condition was determined as: when a solution of 0.025 mmol m L-1 guaiazulene in 80% aqueous THF was treated with four volumes of bromine at a drop rate of 0.1 m L min-1 and four volumes of acetic acid at-5℃ for three hours, the yield of guaiazulene-2,9-dione was 23.72%. This was the first report concerning optimized one-step synthesis to provide a convenient method for the large preparation of guaiazulene-2,9-dione.
基金financial support from the Science and Technology Department of Liaoning Province(No.2011220022)
文摘A simple and efficient procedure was developed for the synthesis of 11H（2H）-4-oxothiophene[3＇,4＇：6,5]pyrido[3,2-a]azulene-10-carboxylates（3） in moderate to good yields via the Gewald reaction of ethyl 1-cyanoacetyl-2-methoxyazulene-3-carboxylate（1） with carbonyl compounds（2） and elemental sulfur utilizing imidazole as catalyst.This reaction provides a new procedure for synthesis of pyridinone-fused azulenes.
基金Project supported by the National Natural Science Foundation of China （No. 20472079） and Anhui Provincial Natural Science Faundation （No 070416237）.
文摘In the study, the X-H （X=CH2, NH, O） bond dissociation energies （BDE） of para-substituted azulene （Y-C10H8X-H） were predicted theoretically for the first time using Density Functronal Theory （DFT） methods at UB3LYP/6-311 ＋ ＋g（2df,2p）//UB3LYP/6-31 ＋g（d） level. It was found that the substituents exerted similar effects on the X-H BDE of azulene as those on benzene, except for 6-substituted 2-methylazulene. Owing to the substituent-dipole interaction, the reaction constants （ρ^＋） of 2- and 6-Y-CIoHsX-H （X=NH and O only） varied violently. The origin of the substituent effects on the X-H BDE of azulene was found, by both GE/RE and SIE theory, to be directly associated with variation of the radical effects, although the ground effects also played a modest role in determining the net. substituent effects.
基金grateful Ph.D.funding to C.M.L.-A.from the EU Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-CO-FUND,#665992The Centre for Sustainable Chemical Technologies is supported by EPSRC under grant EP/L016354/1EPSRC for DTP Ph.D. funding to L.C.M.
文摘We describe the synthesis and evaluation of an azulene-based chemodosimeter for nitrite.The probe was found to undergo two distinct color changes upon introduction of aqueous nitrite ion.A near-instant formation of a grey color provides a qualitative indication of the presence of nitrite,followed by the formation of a deep-yellow/orange color,the endpoint from which quantitative data can be derived.The azulene probe exhibits 1:1 stoichiometry of reaction with nitrite in water,and is selective for nitrite over other anions.The azulene probe was applied to determine nitrite content in cured meat,and compared with the British Standard testing procedure(Griess test).The value obtained from the azulene-based probe agreed closely with the standard test.Our procedure only requires the preparation of one standard solution,instead of the three required for the standard Griess test.
基金financially supported by the National Natural Science Foundation of China (Nos. 21790362, 22075310 and21522209)the “Strategic Priority Research Program of Chinese Academy of Sciences”(No. XDB12010100)+1 种基金the Science and Technology Commission of Shanghai Municipality (Nos. 19XD1424700 and18JC1410600)SIOC. An early preprint of this work appeared on Chem Rxiv [47]。
文摘Azulene, one of representative nonbenzenoid aromatic hydrocarbons, exhibits unique molecular structure and distinctive physical and chemical properties. Herein, azulenoisoindigo(Az II), an azulene-based isoindigo analogue, is designed and synthesized, which has a twisted molecular backbone and R/Sisomers in single crystals. Interestingly, Az II shows the characteristics of both isoindigo and azulene,such as reversible redox behavior and reversible proton responsiveness. UV-vis-NIR,^(1)H NMR and electron paramagnetic resonance(EPR) measurements were carried out to get insights into the possible mechanism of the proton-responsive property of Az II. The results demonstrated that only one azulenyl moiety of molecule of Az II was protonated and deprotonated, and the protonated Az II can be further oxidized to form azulenium cation radicals.
文摘The study was designed to investigate the anti-inflammatory and composition of essential oil of two plant family Asteraceae, Achillea fragrantissima and Lactuca serriola growing under dry desert condition. The anti-inflammatory effect of volatile oil extracted by hydrodistillation of plants was studied using carrageenan induced paw edema. Essential oil （100 mg/kg） and （200 mg/kg） were tested the two plant show high inhibition after 4 h, concentration （200 mg/kg） show high inhibition than （100 mg/kg） after 4 h. Sesqui sabinene hydrate, Azuline and u-Bisabolol are the main constituents of the volatile oil were investigated by capillary GC （gas chromatography） and GC-MS （gas chromatography-mass spectrometry）. The discussion shows the role of chemical compound azulene in inflammatory inhibition.
文摘Comprehensive Summary Open-shell graphene fragments(OGFs)with non-benzenoid topologies are attracting increasing attention due to their potential applications in organic light-emitting diodes(OLEDs)and organic radical conductors.Herein,we report the synthesis of an air-stable fluorenyl radical derivative(AR1)containing a seven-membered ring,achieving thermodynamic stabilization through the fusion of a naphthalene ring around its periphery and anthracene substituent.
基金supported by the National Natural Science Foundation of China(92156009)the Fundamental Research Funds for the Central Universities(2253200022)the Beijing Municipal Commission of Education,and Beijing Normal University。
文摘The aggregation state modification of graphene,including nanographene molecules,is essential for optimizing their performance in various applications.However,the current understanding of how to regulate the structures and features of nanographene aggregates primarily relies on non-covalent bonding interactions,while achieving exact control remains a significant challenge.Herein,we describe unique occurrence in which aσ-bond is reversibly constructed and subsequently broken to produce dimeric nanographene and monomeric analogues.These molecules are fused with azulene unit(s)at the edge.The acid-driven transformation occurs with a radical mechanism.Moreover,the manipulation of the chemical employed to terminate the reaction can regulate the selective creation of dimer and monomer.As compared to the monomer,the dimer with a helical structure exhibited a substantial rise in the molar absorbance coefficient(ɛ),fluorescence emission,a greater range of electrochemical characteristics,and much enhanced chirality stability.This study presents an unprecedented strategy that can precisely control and modulate the structures of aggregation state and characteristics of nanographene by regulating covalent bond cleavage and formation.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 59790050, 59803007 and 59973024) and National "863" Program (Grant No. 863-715-002-0120).
文摘The molecular first hyperpolarizabilities (β) and electronic properties of some azulenic retinal analogues and their derivatives have been investigated theoretically by employing semiempirical approaches. The results indicate that the protonated Schiff bases (PSB) of the 2-substituted azulenic retinal analogues possess extremely large negative β values and very good transparency. These can be attributed to the large difference between the ground state dipole moment and the first excited state dipole moment according to the electronic property analysis. The characteristic blue-shifted absorption in polar solvents of the 2-substituted PSB chromophores can be well explained by the negative solva-tochromic effects. The largest calculated |μβ| value can reach the magnitude of 10-44 esu, which is close to the highest reported values of synthesized chromophores.
基金the National Natural Science Foundation of China (Nos. 20273023 and 90101026) and the Kay Laboratory for Supramolecular Structure and Material of Ji
文摘The first hyperpolarizabilities of a series of novel azulenic-barbituric acid chromophores have been studied by using 12 excitation wavelengths, ranging from 900 to 1907 nm. The dispersion relation of the first hyperpolariza-bilities of chromophores holds the same tendency as the experimental results. In addition, the static first hyperpo-larizability 0 of molecules was calculated by means of the Sum-Over-States (SOS) expression and the two-level formula respectively. The results show that these molecules possess large static first hyperpolarizabilities and the 0 value increases as the donor or acceptor strength enhances; the distorted degree of molecules has also an important influence on the 0 value.
基金This work is supported by the National Key R&D Program of China(No.2017YFA0204701)the National Natural Science Foundation of China(Nos.21722201,21790360).
文摘Main observation and conclusion By combination of two special structural units,a boron-nitrogen-fused polycyclic aromatic hydrocarbon and azulene with strong intramolecular dipoles,a novel BN aromatics,BN-Az,has been designed and synthesized with unique characteristics.The structure,optical and electrochemical properties,as well as charge transport property of BN-Az have been investigated.Notably,BN-Az selectively responds to fluoride ions and protons with a significant color change,which could also be monitored by NMR spectra and single-crystal X-ray analysis,indicating its potential as an effective ion sensing material in stimuli-responsive electronic devices.
