Bottom sediments of the North American Great Lakes are characterized by a high loading(over 3,000 tonnes)of polyhalogenated carbazoles(PHCZs).The origin of this environmental contaminant loading is unclear.Here,we fir...Bottom sediments of the North American Great Lakes are characterized by a high loading(over 3,000 tonnes)of polyhalogenated carbazoles(PHCZs).The origin of this environmental contaminant loading is unclear.Here,we first examined PHCZs levels and profiles in sediment,lotus,and fish fromthe Ya-Er Lake(China)that has been under the influence of an obsolete chlor-alkali facility for forty years and discovered substantial PHCZs contamination.Among the PHCZs determined,3,6-dichlorocarbazole(36-CCZ)and 3-chlorocarbazole(3-CCZ)were the most frequently detected.Sediments frombackfilled land exhibited ∑_(11)PHCZs at median concentration of 973 ng/g(dry weight),suggesting the chlor-alkali industry as an important source.Even after 20 years of dredging treatment,the concentration of ∑_(11)PHCZs in the sediment of the oxidation ponds(median=41.1 ng/g)remained substantially higher than in other areas globally.Furthermore,the concentration of ∑_(11)PHCZs was found to be higher in surface sediments(median)at 66.7 ng/g if compared to middle(14.1 ng/g)and lower layers(18.2 ng/g),indicating the potential availability of PHCZs from surface sediments to aquatic plants and animals.Notably,this study detected PHCZs in both fish(26.3 ng/g lipid weight)and lotus(14.5 ng/g dry weight),with significant enrichment of 3-monobromocarbazole(3-BCZ)observed in both lotus root systems(bio-soil accumulation factor,BSAF_(root)=5.04)and fish muscle(BSAF_(fish)=3.04).展开更多
New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carb...New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu<sup>3+</sup> ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.展开更多
Polyhalogenated carbazoles(PHCZs)have been widely accepted as emerging pollutants,whereas their ecological and health risks remain uncertain.Herein,female and male Sprague-Dawley(SD)mice were treated with four typical...Polyhalogenated carbazoles(PHCZs)have been widely accepted as emerging pollutants,whereas their ecological and health risks remain uncertain.Herein,female and male Sprague-Dawley(SD)mice were treated with four typical PHCZs to investigate their negative consequences,along with alternations in gutmicrobiota to indicate underlyingmechanisms.In female mice,the relative liver weight ratio increased after four PHCZs exposure;2-bromocarbazole(2-BCZ)increased urine glucose level;3-bromocarbazole(3-BCZ)decreased the glucose and total cholesterol levels;3,6-dichlorocarbazole(3,6-DCCZ)decreased glucose level.The only disturbed biochemical index in male mice was the promoted alkaline phosphatase(ALP)level by 3,6-DCCZ.We also found that the differential blood biochemical indices were correlated with gut microbiota.3-BCZ and 3,6-DCCZ altered Bacteroidetes and Proteobacteria phyla in female and male mice,which were correlated with metabolic disorders.Our findings demonstrated the correlation between PHCZs induced potential hepatotoxicity andmetabolic disordersmay be due to their dioxin-like potentials and endocrine disrupting activities,and the gender differences might result from their estrogenic activities.Overall,data presented here can help to evaluate the ecological and health risks of PHCZs and reveal the underlying mechanisms.展开更多
Polyhalogenated carbazoles(PHCZs)are recently raising much attention due to their toxicity and ubiquitous environmental distribution.However,little knowledge is known about their ambient occurrences and the potential ...Polyhalogenated carbazoles(PHCZs)are recently raising much attention due to their toxicity and ubiquitous environmental distribution.However,little knowledge is known about their ambient occurrences and the potential source.In this study,we developed an analytical method based on GC-MS/MS to simultaneously determine 11 PHCZs in PM_(2.5) from urban Beijing,China.The optimized method provided low method limit of quantifications(MLOQs,1.45–7.39 fg/m^(3))and satisfied recoveries(73.4%–109.5%).This method was applied to analyze the PHCZs in the outdoor PM_(2.5)(n=46)and fly ash(n=6)collected from 3 kinds of surrounding incinerator plants(steel plant,medical waste incinerator and domestic waste incinerator).The levels of Σ_(11)PHCZs in PM_(2.5) ranged from 0.117 to 5.54 pg/m^(3)(median 1.18 pg/m^(3)).3-chloro-9H-carbazole(3-CCZ),3-bromo-9H-carbazole(3-BCZ),and 3,6-dichloro-9Hcarbazole(36-CCZ)were the dominant compounds,accounting for 93%.3-CCZ and 3-BCZ were significantly higher in winter due to the high PM_(2.5) concentration,while 36-CCZ was higher in spring,which may be related to the resuspending of surface soil.Furthermore,the levels of11PHCZs in fly ash ranged from 338 to 6101 pg/g.3-CCZ,3-BCZ and 36-CCZ accounted for 86.0%.The congener profiles of PHCZs between fly ash and PM_(2.5) were highly similar,indicating that combustion process could be an important source of ambient PHCZs.To the best of our knowledge,this is the first research providing the occurrences of PHCZs in outdoor PM_(2.5).展开更多
The integration of multiscale and multicomponent of molecules and nanoparticles into thin films for applications requires the abilities of controlled their processing and assembly,which has been an great challenge bec...The integration of multiscale and multicomponent of molecules and nanoparticles into thin films for applications requires the abilities of controlled their processing and assembly,which has been an great challenge because of the difficulty in manipulating the various materials such as small molecules,complexes,polymers,and inorganic nanomaterials through synergetic combinations of chemical or physical fabrications.Eletropolymerization is of great significance to fabricate polymeric film materials straight on the conductive substrates with tunable morphologies and thicknesses.However,unlimited electrochemical reactions（polymerization）have been usually leading to disadvantageous in ill-defined structure and highly doped state.Thanks to finding of exceptional electrochemical reaction（oligomerization）of N-alkylcarbazole,electrochemical layer by layer assembly has emerged as a promising strategy for a wide library of applications.The capability of this strategy can manipulate various molecules and nanoparticles into the scale and component controllable thin films.Unlike other electropolymerizable precursors such as aniline and thiophene,the resulting di-N-alkylcarbazole is transparent in the visible light region and thus does not impair the intrinsic properties of the components in the film.This account highlights of the typical findings in investigating both single-and multi-components thin films as a forum for discussing new opportunities in exploiting novel designs and applications of optical thin films.展开更多
Atropisomeric carbazoles are widely used in organic synthesis,medicine,and material science.Although the enantioselective coupling of two aryl units provides a straightforward means to access biaryl atropisomers,this ...Atropisomeric carbazoles are widely used in organic synthesis,medicine,and material science.Although the enantioselective coupling of two aryl units provides a straightforward means to access biaryl atropisomers,this approach has yet to be explored extensively for carbazole-based structures due to their diverse reactive sites.This report presents a chiral phosphoric acidcatalyzed approach to achieve enantioselective synthesis of carbazole-based atropisomers with exceptional chemo-,site-,and stereoselectivities.The key innovation lies in the organocatalytic activation of the heteroaromatic compound,which represents the first example of converting nucleophilic carbazoles into electrophilic species,thereby enriching the field of carbazole chemistry.Hydrazine-decorated carbazoles undergo oxidative homo-coupling to furnish atropisomeric bicarbazoles,while the inclusion of external indole nucleophiles as coupling partners leads to the formation of indole-carbazole atropisomers.A novel chiral phosphine ligand has been synthesized on the homo-coupled bicarbazole skeleton.The distinctive features of this complex reaction system were enabled by the in situ oxidation of both substrates and products,as well as the judicious choice of indoles as nucleophiles to regulate selective coupling.展开更多
In contrast to the predominant mono or difunctionalization of alkenes,the multi-site functionalization of alkenes involving the synergistic formation of more than two new C–C or C–X bonds is much challenging,especia...In contrast to the predominant mono or difunctionalization of alkenes,the multi-site functionalization of alkenes involving the synergistic formation of more than two new C–C or C–X bonds is much challenging,especially for developing new reaction pathway to afford the functional heterocycle compounds with aggregation-induced emission(AIE)property has been rarely reported.In present work,the multi-site functionalization of in situ generated alkenes with indoles has been developed for the synthesis of diversely functionalized carbazoles through the synergistic construction of multiple C–C bonds and C=O bond.A proposed reaction sequence involving C–H alkenylation/radical oxygen atom transfer/Diels-Alder cycloaddition/dehydrogenative aromatization was supported by experiments and density functional theory calculations.Further derivative carbazole-linked-quinoxaline skeletons represent a class of AIEgens with acceptor-donor-acceptor configuration,which generated the desired twisted intramolecular charge transfer(TICT)AIE properties and could be used as fluorescent probes for detecting the micrometer-sized phase separation of polymer blends.The protocol provides a concise route for the synthesis and application of carbazole-based AIE luminogens.展开更多
The synthesis of carbazoles based on the electrochemical Pd-catalyzed intramolecular C-H amination of 2-amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions.The reaction can b...The synthesis of carbazoles based on the electrochemical Pd-catalyzed intramolecular C-H amination of 2-amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions.The reaction can be carried out in undivided cell without the addition of external chemical oxidant.Besides good functional group compatibility,the desired carbazoles can be scaled up and modified easily.Compared with previous methods,this protocol affords a simple and sustainable avenue for the construction of car-bazoles.展开更多
Fifteen novel carbazole alkaloids,euchrestifolines A-O(1-15),were obtained from Murraya euchrestifolia.Their structures were elucidated by spectroscopic analysis,Mosher's ester,calculated ECD,and transition metal ...Fifteen novel carbazole alkaloids,euchrestifolines A-O(1-15),were obtained from Murraya euchrestifolia.Their structures were elucidated by spectroscopic analysis,Mosher's ester,calculated ECD,and transition metal complex ECD methods.Notably,euchrestifolines A-C(1-3)are the first naturally occurring pyrrolidone carbazoles to be identified,while euchrestifolines D-F(4-6)represent rare carbazole alkaloids containing a phenylpropanyl moiety;euchrestifoline G(7)features a unique benzopyranocarbazole skeleton.More importantly,these compounds exhibited significant anti-ferroptotic activity,along with inhibitory effects of nitric oxide(NO)production and notable cytotoxicity.This study marks the first disclosure of carbazole's inhibitory effects against ferroptosis,and the EC_(50) values of some carbazoles ranging from 0.04 to 1 μM,substantially lower than the positive control,ferrostatin-1.In sum,this research not only enhances our understanding of carbazole alkaloids but also opens new avenues for the discovery of ferroptosis-related leading compounds.展开更多
Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improv...Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improve thermal stability and lower the possibility to generate fluorescence quenching of organic blue-light emitting materials formed by carbazole,a linear organic molecule containing carbazole and triarylamine group,named N4,N4’-bis(9-ethyl-9H-carbazol-3-yl)-N4,N4’-diphenyl-[1,1’-biphenyl]-4,4’-diamine(DPECB),was synthesized via the Buchwald-Hartwig reaction.The structure of DPECB was characterized by nuclear magnetic resonance(NMR)and infrared spectroscopy.The UV-Vis absorption spectrum shows that DPECB exhibits two strong absorption peaks in the near ultraviolet region(around 305 and 355 nm).The fluorescence emission spectrum indicates that DPECB displays blue light emission both in solution(428-445 nm)and solid-state(466 nm).Additionally,DPECB shows clearly aggregation-induced emission enhancement(AIEE)effect in the mixed solvent of DMF/H2O.As the thermogravimetric analysis shows,DPECB demonstrates excellent thermostability with a 5%decomposition temperature of 457℃owing to the introduction of triarylamine group.The electrochemical property of DPECB was studied through cyclic voltammetry,and its HOMO and LUMO energy levels are-5.27 and-2.25 eV,respectively.These results indicate that DPECB is a promising blue-light emitting material with potential commercial applications.展开更多
Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in ...Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.展开更多
Albeit their high efficiencies, the operational stability of the organic light emitting diodes(OLEDs) based on thermally activated delayed fluorescence(TADF) emitters is still far from satisfaction, and few strategies...Albeit their high efficiencies, the operational stability of the organic light emitting diodes(OLEDs) based on thermally activated delayed fluorescence(TADF) emitters is still far from satisfaction, and few strategies have been proposed to improve their stability. Here, we show that by modifying the carbazole unit, one of the most commonly used donors in TADF emitters, with peripheral groups, both the device efficiency and operational stability can be greatly improved. Awell-known TADF molecule—4,5-di(9H-carbazol-9-yl)phthalonitrile(2CzPN) was chosen as the prototype and modified by introducing peripheral tert-butyl and phenyl groups to the 3,6-positions of the carbazole(named 2tBuCzPN and 2PhCzPN, respectively). The introduced groups not only improve the compounds' electrochemical stabilities referred to the cyclic voltammetry multi-sweep results, but also promote their photoluminescence quantum yields. Furthermore, reduced singlet-triplet energy gaps are observed, leading to the shortened exciton lifetimes which are benefit to suppress the exciton annihilations. Besides, the steric hindrance of introduced phenyl groups can partly restrain the concentration quenching of the TADF emitter. Consequently, OLEDs based on 2tBuCzPN and 2PhCzPN achieved improved maximum external quantum efficiencies(EQEs) of 17.0% and 14.0%, respectively(compared to 8.5% for 2CzPN). Meanwhile, 2PhCzPN based OLED showed reduced roll-off characteristics and a longer lifetime of 7.8 times higher than that of 2CzPN, testifying the effectiveness of subtle modification of the unstable moieties in simultaneous enhancement of efficiency and stability of OLEDs based on TADF emitters.展开更多
A convenient and highly efficient method is described for the synthesis of N-methoxycarbazole derivatives,including those with sterically demanding,benzannulated,or strongly electron-donating or-withdrawing substituen...A convenient and highly efficient method is described for the synthesis of N-methoxycarbazole derivatives,including those with sterically demanding,benzannulated,or strongly electron-donating or-withdrawing substituents.Various N-methoxycarbazole derivatives were directly prepared in good-to-moderate yields by the Pd_(2)(dba)_(3)CHCl_(3)/9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene-catalyzed reactions of the corresponding dibromobiphenyl compounds and methoxyamine.Based on this methodology,the first total synthesis of 3,3′-[oxybis(methylene)]bis(9-methoxy-9H-carbazole),an antimicrobial dimeric carbazole alkaloid previously isolated from the stem bark of Murraya koenigii,was achieved in 18% yield over seven steps from 1,2-dibromobenzene.展开更多
Migration pathways and distances of the oils in reservoir are thought to affect the distribution of pyrrolic compounds such as carbazole,its alkyl derivatives(alkylated carbazoles)and benzocarbazoles,although other fa...Migration pathways and distances of the oils in reservoir are thought to affect the distribution of pyrrolic compounds such as carbazole,its alkyl derivatives(alkylated carbazoles)and benzocarbazoles,although other factors,including maturity and depositional environments may also affect the distribution of these organic nitrogen compounds.In this study,14 oil samples produced from conventional reservoirs in Pauls Valley,south Oklahoma were investigated using organic geochemical techniques.The sterane and hopane fingerprints suggest that most of the oils were sourced from the Devonian Woodford shale.Maturity parameters consistently indicate that the maturity level of the studied samples are all of similar maturity(Rc=~0.7%),suggesting the distribution of the organic nitrogen organic compounds is possibly reflecting variations in relative migration distances.The distribution of alkylcarbazoles revealed a preferential enrichment during migration,with the nitrogen-shielded alkylcarbazole tending to be enriched relative to the nitrogen-semi-shielded alkylcarbozoles particularly in oils produced close to the Arbuckle uplift to the east.Correspondingly,another family of pyrrolic compounds,benzocarbazoles,whose distributions also indicated that the Pauls Valley Woodford oils came from deeper part of the Anadarko Basin as the benzo-[a]/([a]+[c])-carbazole ratios decrease eastwards.In more specific migration systems,although the pyrrolic compound indicators are potentially disturbed by the structural complexes,the general migration directions suggest that the studied oils in Pauls Valley Hunton uplift were sourced from the deep basin area,and migrate upwards in porous sediments due to the buoyancy.This study investigates the feasibility of using pyrrolic compounds to estimate relative migration distances and will aid in the interpretation of migration history by using the distribution of carbazole,alkylated carbazoles,benzocarbazoles isomers in the Anadarko and Ardmore Basin petroleum systems.展开更多
Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry.The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in che...Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry.The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in chemical engineering.Deep eutectic solvents (DESs) as a sustainable green separation solvent have been proposed for the separation of carbazole from model anthracene oil.In this research,three quaternary ammonium-based DESs were prepared using ethylene glycol (EG) as hydrogen bond donor and tetrabutylammonium chloride (TBAC),tetrabutylammonium bromide or choline chloride as hydrogen bond acceptors.To explore their extraction performance of carbazole,the conductor-like screening model for real solvents (COSMO-RS) model was used to predict the activity coefficient at infinite dilution (γ^(∞)) of carbazole in DESs,and the result indicated TBAC:EG (1:2) had the stronger extraction ability for carbazole due to the higher capacity at infinite dilution (C^(∞)) value.Then,the separation performance of these three DESs was evaluated by experiments,and the experimental results were in good agreement with the COSMO-RS prediction results.The TBAC:EG (1:2) was determined as the most promising solvent.Additionally,the extraction conditions of TBAC:EG (1:2) were optimized,and the extraction efficiency,distribution coefficient and selectivity of carbazole could reach up to 85.74%,30.18 and 66.10%,respectively.Moreover,the TBAC:EG (1:2) could be recycled by using environmentally friendly water as antisolvent.In addition,the separation performance of TBAC:EG (1:2) was also evaluated by real crude anthracene,the carbazole was obtained with purity and yield of 85.32%,60.27%,respectively.Lastly,the extraction mechanism was elucidated byσ-profiles and interaction energy analysis.Theoretical calculation results showed that the main driving force for the extraction process was the hydrogen bonding ((N–H...Cl) and van der Waals interactions (C–H...O and C–H...π),which corresponding to the blue and green isosurfaces in IGMH analysis.This work presented a novel method for separating carbazole from crude anthracene oil,and will provide an important reference for the separation of other high value-added products from coal tar.展开更多
Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In th...Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In this work,the first HOF for organic acid sensing is reported by constructing a multiplepyridine carbazole-based dense HOF,namely HOF-FJU-206,from a tripyridine-carbazole molecular 3,6-bis(pyridin-4-yl)-9-(4-(pyridin-4-yl)phenyl)-9H-carbazole(CPPY)with carbazole center for luminescence,pyridyl sites for its responsive of hydrogen proton,and narrow channels in the dense framework for the diffusion of hydrogen protons.HOF-FJU-206 exhibits differential responsively fluorescence sensing and recovery properties to formic,acetic,and propionic acids with different molecular sizes and p Kavalue(acid dissociation constant).The dissociation degree of various acids can be determined by analyzing the slope of changes in both peak wavelength and intensity of in-situ fluorescence,which easily enables the dual-corrective recognition of different acids.The varying degree of protonation at pyridine sites is proved to be the reason for differential sensing of various acids,as demonstrated by1H NMR spectra,X-ray photoelectron spectroscopy(XPS)characterization,and modeling studies.展开更多
A SPE/GC-MS method for separation and determination of carbazoles in crude oil was developed.Alumina and silicic acid solid-phase extraction(SPE) columns were used to separate resin from crude oil and neutral nitrogen...A SPE/GC-MS method for separation and determination of carbazoles in crude oil was developed.Alumina and silicic acid solid-phase extraction(SPE) columns were used to separate resin from crude oil and neutral nitrogen compounds from nitrogen riched resin.Carbazole and its alkylation series were quantitatively analysed by use of deuterate carbazole as an internal standard and the 9-benzocarbazole as an recovery rate standard.The modified method was very suitable for batch processing in organic geochemistry owing to its low cost,time saving,environmental friendliness.展开更多
AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) a...AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) and pancreatic stress kinase activity was determined. Parameters to assess pancreatitis included trypsin, amylase, lipase, pancreatic weight and histology. RESULTS: JNK inhibition with CEP1347 ameliorated pancreatitis, reducing pancreatic edema. In contrast, p38 inhibition with SB203580 aggravated pancreatitis with higher trypsin levels and, with induction of acinar necrosis not normally found after cerulein hyperstimulation. Simultaneous treatment with both CEP1347 and SB203580 mutually abolished the effects of either compound on cerulein pancreatitis. CONCLUSION: Stress kinases modulate pancreatitis differentially. JNK seems to promote pancreatitis development, possibly by supporting inflammatory reactions such as edema formation while its inhibition ameliorates pancreatitis. In contrast, p38 may help reduce organ destruction while inhibition of p38 during induction of cerulein pancreatitis leads to the occurrence of acinar necrosis.展开更多
Carbazole-core multi-branched chromophores 9-ethyl- 3, 6-bis （ 2- { 4- [ 5- （4-tert-butyl-phenyl） - [ 1, 3, 4 ] oxadiazol-2-yl ] - phenyl }-vinyl） -carbazole（3） and 9-ethyl-3-（ 2- {4-[ 5-（4-tert-butyl- phenyl...Carbazole-core multi-branched chromophores 9-ethyl- 3, 6-bis （ 2- { 4- [ 5- （4-tert-butyl-phenyl） - [ 1, 3, 4 ] oxadiazol-2-yl ] - phenyl }-vinyl） -carbazole（3） and 9-ethyl-3-（ 2- {4-[ 5-（4-tert-butyl- phenyl） -[ 1, 3, 4 ] oxadiazol-2-yl ] -phenyl }-vinyl ） -carbazole （ 2 ） are synthesized through Wittig reaction and characterized by nuclear magnetic resonance（NMR）and infrared（IR）. The two- photon absorption properties of chromophores are investigated. These chromophores exhibit large two-photon absorption crosssections and strong blue two-photon excited fluorescence. The cooperative enhancement of two-photon absorption（TPA） in the multi-branched structures is observed. This enhancement is partly attributed to the electronic coupling between the branches. The electronic push-pull structures in the arm and their cooperative effects help the extended charge transfer for TPA.展开更多
The direction of oil charges within a field in the Niger Delta, Nigeria was determined by the sum of differences ranking method of carbazole concentrations after ascertaining other possible geological constraints on t...The direction of oil charges within a field in the Niger Delta, Nigeria was determined by the sum of differences ranking method of carbazole concentrations after ascertaining other possible geological constraints on their compositional variations. The principle is that the smaller the sum, the closer the well to the source kitchen. The approach makes use of carbazoles' interaction with the matrix, which leads to a reduction in their concentration with increasing distance from the source kitchen, allowing prediction of the charging direction. A wide range of compositional variations was observed for C1(806.72–2152.90 lg/g) and C2(767–2469.72 lg/g) carbazoles within the field. Based on these results, we inferred a filling pathway orientation from west to east. This suggests that the source kitchen—the most promising region for oil exploration—is located in the western part of the oil field.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750400)the National Natural Science Foundation of China(Nos.22076201,21936007 and 22376204).
文摘Bottom sediments of the North American Great Lakes are characterized by a high loading(over 3,000 tonnes)of polyhalogenated carbazoles(PHCZs).The origin of this environmental contaminant loading is unclear.Here,we first examined PHCZs levels and profiles in sediment,lotus,and fish fromthe Ya-Er Lake(China)that has been under the influence of an obsolete chlor-alkali facility for forty years and discovered substantial PHCZs contamination.Among the PHCZs determined,3,6-dichlorocarbazole(36-CCZ)and 3-chlorocarbazole(3-CCZ)were the most frequently detected.Sediments frombackfilled land exhibited ∑_(11)PHCZs at median concentration of 973 ng/g(dry weight),suggesting the chlor-alkali industry as an important source.Even after 20 years of dredging treatment,the concentration of ∑_(11)PHCZs in the sediment of the oxidation ponds(median=41.1 ng/g)remained substantially higher than in other areas globally.Furthermore,the concentration of ∑_(11)PHCZs was found to be higher in surface sediments(median)at 66.7 ng/g if compared to middle(14.1 ng/g)and lower layers(18.2 ng/g),indicating the potential availability of PHCZs from surface sediments to aquatic plants and animals.Notably,this study detected PHCZs in both fish(26.3 ng/g lipid weight)and lotus(14.5 ng/g dry weight),with significant enrichment of 3-monobromocarbazole(3-BCZ)observed in both lotus root systems(bio-soil accumulation factor,BSAF_(root)=5.04)and fish muscle(BSAF_(fish)=3.04).
文摘New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu<sup>3+</sup> ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.
基金supported by Joint Innovation Fund for Regional Development of National Natural Science Foundation of China(No.U20A20134)Leading Talent of Technological Innovation of Ten-Thousands Talents Program of Zhejiang Province(No.2020R52012).
文摘Polyhalogenated carbazoles(PHCZs)have been widely accepted as emerging pollutants,whereas their ecological and health risks remain uncertain.Herein,female and male Sprague-Dawley(SD)mice were treated with four typical PHCZs to investigate their negative consequences,along with alternations in gutmicrobiota to indicate underlyingmechanisms.In female mice,the relative liver weight ratio increased after four PHCZs exposure;2-bromocarbazole(2-BCZ)increased urine glucose level;3-bromocarbazole(3-BCZ)decreased the glucose and total cholesterol levels;3,6-dichlorocarbazole(3,6-DCCZ)decreased glucose level.The only disturbed biochemical index in male mice was the promoted alkaline phosphatase(ALP)level by 3,6-DCCZ.We also found that the differential blood biochemical indices were correlated with gut microbiota.3-BCZ and 3,6-DCCZ altered Bacteroidetes and Proteobacteria phyla in female and male mice,which were correlated with metabolic disorders.Our findings demonstrated the correlation between PHCZs induced potential hepatotoxicity andmetabolic disordersmay be due to their dioxin-like potentials and endocrine disrupting activities,and the gender differences might result from their estrogenic activities.Overall,data presented here can help to evaluate the ecological and health risks of PHCZs and reveal the underlying mechanisms.
基金supported by the National Key Research and Development Program of China(Nos.2018YFA0901104 and 2019YFE0111100)the National Natural Science Foundation of China(No.91743206)the Special Project of Eco-Environmental Technology for Peak Carbon Dioxide Emissions and Carbon Neutrality(No.RCEES-TDZ-2021-23).
文摘Polyhalogenated carbazoles(PHCZs)are recently raising much attention due to their toxicity and ubiquitous environmental distribution.However,little knowledge is known about their ambient occurrences and the potential source.In this study,we developed an analytical method based on GC-MS/MS to simultaneously determine 11 PHCZs in PM_(2.5) from urban Beijing,China.The optimized method provided low method limit of quantifications(MLOQs,1.45–7.39 fg/m^(3))and satisfied recoveries(73.4%–109.5%).This method was applied to analyze the PHCZs in the outdoor PM_(2.5)(n=46)and fly ash(n=6)collected from 3 kinds of surrounding incinerator plants(steel plant,medical waste incinerator and domestic waste incinerator).The levels of Σ_(11)PHCZs in PM_(2.5) ranged from 0.117 to 5.54 pg/m^(3)(median 1.18 pg/m^(3)).3-chloro-9H-carbazole(3-CCZ),3-bromo-9H-carbazole(3-BCZ),and 3,6-dichloro-9Hcarbazole(36-CCZ)were the dominant compounds,accounting for 93%.3-CCZ and 3-BCZ were significantly higher in winter due to the high PM_(2.5) concentration,while 36-CCZ was higher in spring,which may be related to the resuspending of surface soil.Furthermore,the levels of11PHCZs in fly ash ranged from 338 to 6101 pg/g.3-CCZ,3-BCZ and 36-CCZ accounted for 86.0%.The congener profiles of PHCZs between fly ash and PM_(2.5) were highly similar,indicating that combustion process could be an important source of ambient PHCZs.To the best of our knowledge,this is the first research providing the occurrences of PHCZs in outdoor PM_(2.5).
基金supported by the National Natural Science Foundation of China (Nos. 21374115, 51573181, and 21504088)the Hundred Talents Program, CAS, China
文摘The integration of multiscale and multicomponent of molecules and nanoparticles into thin films for applications requires the abilities of controlled their processing and assembly,which has been an great challenge because of the difficulty in manipulating the various materials such as small molecules,complexes,polymers,and inorganic nanomaterials through synergetic combinations of chemical or physical fabrications.Eletropolymerization is of great significance to fabricate polymeric film materials straight on the conductive substrates with tunable morphologies and thicknesses.However,unlimited electrochemical reactions（polymerization）have been usually leading to disadvantageous in ill-defined structure and highly doped state.Thanks to finding of exceptional electrochemical reaction（oligomerization）of N-alkylcarbazole,electrochemical layer by layer assembly has emerged as a promising strategy for a wide library of applications.The capability of this strategy can manipulate various molecules and nanoparticles into the scale and component controllable thin films.Unlike other electropolymerizable precursors such as aniline and thiophene,the resulting di-N-alkylcarbazole is transparent in the visible light region and thus does not impair the intrinsic properties of the components in the film.This account highlights of the typical findings in investigating both single-and multi-components thin films as a forum for discussing new opportunities in exploiting novel designs and applications of optical thin films.
基金supported by the National Key R&D Program of China(2022YFA1503703,2021YFF0701604)the National Natural Science Foundation of China(22425011,22231004,22271071)+6 种基金the Guangdong Innovative Program(2019BT02Y335)the Guangdong Basic and Applied Basic Research Foundation(2024B1515020055)the New Cornerstone Science Foundation through the Xplorer PrizeShenzhen Science and Technology Program(KQTD20210811090112004)the High Level of Special Funds(G03050K003)the Natural Science Foundation of Zhejiang Province(LY20B020010)Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province,Department of Chemistry,School of Science,Westlake University。
文摘Atropisomeric carbazoles are widely used in organic synthesis,medicine,and material science.Although the enantioselective coupling of two aryl units provides a straightforward means to access biaryl atropisomers,this approach has yet to be explored extensively for carbazole-based structures due to their diverse reactive sites.This report presents a chiral phosphoric acidcatalyzed approach to achieve enantioselective synthesis of carbazole-based atropisomers with exceptional chemo-,site-,and stereoselectivities.The key innovation lies in the organocatalytic activation of the heteroaromatic compound,which represents the first example of converting nucleophilic carbazoles into electrophilic species,thereby enriching the field of carbazole chemistry.Hydrazine-decorated carbazoles undergo oxidative homo-coupling to furnish atropisomeric bicarbazoles,while the inclusion of external indole nucleophiles as coupling partners leads to the formation of indole-carbazole atropisomers.A novel chiral phosphine ligand has been synthesized on the homo-coupled bicarbazole skeleton.The distinctive features of this complex reaction system were enabled by the in situ oxidation of both substrates and products,as well as the judicious choice of indoles as nucleophiles to regulate selective coupling.
文摘In contrast to the predominant mono or difunctionalization of alkenes,the multi-site functionalization of alkenes involving the synergistic formation of more than two new C–C or C–X bonds is much challenging,especially for developing new reaction pathway to afford the functional heterocycle compounds with aggregation-induced emission(AIE)property has been rarely reported.In present work,the multi-site functionalization of in situ generated alkenes with indoles has been developed for the synthesis of diversely functionalized carbazoles through the synergistic construction of multiple C–C bonds and C=O bond.A proposed reaction sequence involving C–H alkenylation/radical oxygen atom transfer/Diels-Alder cycloaddition/dehydrogenative aromatization was supported by experiments and density functional theory calculations.Further derivative carbazole-linked-quinoxaline skeletons represent a class of AIEgens with acceptor-donor-acceptor configuration,which generated the desired twisted intramolecular charge transfer(TICT)AIE properties and could be used as fluorescent probes for detecting the micrometer-sized phase separation of polymer blends.The protocol provides a concise route for the synthesis and application of carbazole-based AIE luminogens.
基金This work was supported by the National Natural Science Foundation of China(No.21520102003)the Hubei Province Natural Science Foundation of China(No.2017CFA010).The Program of Introducing Talents of Discipline to Universities of China(111 Program)is also appreciated.
文摘The synthesis of carbazoles based on the electrochemical Pd-catalyzed intramolecular C-H amination of 2-amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions.The reaction can be carried out in undivided cell without the addition of external chemical oxidant.Besides good functional group compatibility,the desired carbazoles can be scaled up and modified easily.Compared with previous methods,this protocol affords a simple and sustainable avenue for the construction of car-bazoles.
基金the National Natural Science Foundation of China(NSFC)for their financial support through grant numbers 81973199,82173949,U23A20514,81773864,and 81473106the funding provided by the Key Research and Development Project of Shandong Province(2021CXGC010507).
文摘Fifteen novel carbazole alkaloids,euchrestifolines A-O(1-15),were obtained from Murraya euchrestifolia.Their structures were elucidated by spectroscopic analysis,Mosher's ester,calculated ECD,and transition metal complex ECD methods.Notably,euchrestifolines A-C(1-3)are the first naturally occurring pyrrolidone carbazoles to be identified,while euchrestifolines D-F(4-6)represent rare carbazole alkaloids containing a phenylpropanyl moiety;euchrestifoline G(7)features a unique benzopyranocarbazole skeleton.More importantly,these compounds exhibited significant anti-ferroptotic activity,along with inhibitory effects of nitric oxide(NO)production and notable cytotoxicity.This study marks the first disclosure of carbazole's inhibitory effects against ferroptosis,and the EC_(50) values of some carbazoles ranging from 0.04 to 1 μM,substantially lower than the positive control,ferrostatin-1.In sum,this research not only enhances our understanding of carbazole alkaloids but also opens new avenues for the discovery of ferroptosis-related leading compounds.
基金Fundamental Research Program of Shanxi Province(20210302124637,202203021211102,J20230701)。
文摘Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improve thermal stability and lower the possibility to generate fluorescence quenching of organic blue-light emitting materials formed by carbazole,a linear organic molecule containing carbazole and triarylamine group,named N4,N4’-bis(9-ethyl-9H-carbazol-3-yl)-N4,N4’-diphenyl-[1,1’-biphenyl]-4,4’-diamine(DPECB),was synthesized via the Buchwald-Hartwig reaction.The structure of DPECB was characterized by nuclear magnetic resonance(NMR)and infrared spectroscopy.The UV-Vis absorption spectrum shows that DPECB exhibits two strong absorption peaks in the near ultraviolet region(around 305 and 355 nm).The fluorescence emission spectrum indicates that DPECB displays blue light emission both in solution(428-445 nm)and solid-state(466 nm).Additionally,DPECB shows clearly aggregation-induced emission enhancement(AIEE)effect in the mixed solvent of DMF/H2O.As the thermogravimetric analysis shows,DPECB demonstrates excellent thermostability with a 5%decomposition temperature of 457℃owing to the introduction of triarylamine group.The electrochemical property of DPECB was studied through cyclic voltammetry,and its HOMO and LUMO energy levels are-5.27 and-2.25 eV,respectively.These results indicate that DPECB is a promising blue-light emitting material with potential commercial applications.
基金the National Natural Science Foundation of China(51925206,U1932214,52302052)the National Natural Science Foundation of China(52322318)+6 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)the Fundamental Research Funds for the Central Universities(WK2060000051,20720220009)the National Key Research and Development Program of China(No.2023YFB3809700)the Innovation and Technology Fund(GHP/100/20SZ,GHP/102/20GD,MRP/040/21X,ITS/147/22FP)the Research Grants Council of Hong Kong Grant(N_City U102/23,C4005-22Y,C1055-23G,11306521)the Green Tech Fund(GTF202020164)the Science Technology and Innovation Committee of Shenzhen Municipality(SGDX20210823104002015,JCYJ20220818101018038)。
文摘Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.
基金supported by the National Key Research and Development Program of China (2017YFA0204501)the National Science Fund of China (51525304, 61890942, U1601651)
文摘Albeit their high efficiencies, the operational stability of the organic light emitting diodes(OLEDs) based on thermally activated delayed fluorescence(TADF) emitters is still far from satisfaction, and few strategies have been proposed to improve their stability. Here, we show that by modifying the carbazole unit, one of the most commonly used donors in TADF emitters, with peripheral groups, both the device efficiency and operational stability can be greatly improved. Awell-known TADF molecule—4,5-di(9H-carbazol-9-yl)phthalonitrile(2CzPN) was chosen as the prototype and modified by introducing peripheral tert-butyl and phenyl groups to the 3,6-positions of the carbazole(named 2tBuCzPN and 2PhCzPN, respectively). The introduced groups not only improve the compounds' electrochemical stabilities referred to the cyclic voltammetry multi-sweep results, but also promote their photoluminescence quantum yields. Furthermore, reduced singlet-triplet energy gaps are observed, leading to the shortened exciton lifetimes which are benefit to suppress the exciton annihilations. Besides, the steric hindrance of introduced phenyl groups can partly restrain the concentration quenching of the TADF emitter. Consequently, OLEDs based on 2tBuCzPN and 2PhCzPN achieved improved maximum external quantum efficiencies(EQEs) of 17.0% and 14.0%, respectively(compared to 8.5% for 2CzPN). Meanwhile, 2PhCzPN based OLED showed reduced roll-off characteristics and a longer lifetime of 7.8 times higher than that of 2CzPN, testifying the effectiveness of subtle modification of the unstable moieties in simultaneous enhancement of efficiency and stability of OLEDs based on TADF emitters.
基金supported by the Natural Science Foundation of Tianjin,China(No.15JCYBJC20100).
文摘A convenient and highly efficient method is described for the synthesis of N-methoxycarbazole derivatives,including those with sterically demanding,benzannulated,or strongly electron-donating or-withdrawing substituents.Various N-methoxycarbazole derivatives were directly prepared in good-to-moderate yields by the Pd_(2)(dba)_(3)CHCl_(3)/9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene-catalyzed reactions of the corresponding dibromobiphenyl compounds and methoxyamine.Based on this methodology,the first total synthesis of 3,3′-[oxybis(methylene)]bis(9-methoxy-9H-carbazole),an antimicrobial dimeric carbazole alkaloid previously isolated from the stem bark of Murraya koenigii,was achieved in 18% yield over seven steps from 1,2-dibromobenzene.
基金the support from the Organic Geochemistry Lab of the OU and Oklahoma Geological Survey。
文摘Migration pathways and distances of the oils in reservoir are thought to affect the distribution of pyrrolic compounds such as carbazole,its alkyl derivatives(alkylated carbazoles)and benzocarbazoles,although other factors,including maturity and depositional environments may also affect the distribution of these organic nitrogen compounds.In this study,14 oil samples produced from conventional reservoirs in Pauls Valley,south Oklahoma were investigated using organic geochemical techniques.The sterane and hopane fingerprints suggest that most of the oils were sourced from the Devonian Woodford shale.Maturity parameters consistently indicate that the maturity level of the studied samples are all of similar maturity(Rc=~0.7%),suggesting the distribution of the organic nitrogen organic compounds is possibly reflecting variations in relative migration distances.The distribution of alkylcarbazoles revealed a preferential enrichment during migration,with the nitrogen-shielded alkylcarbazole tending to be enriched relative to the nitrogen-semi-shielded alkylcarbozoles particularly in oils produced close to the Arbuckle uplift to the east.Correspondingly,another family of pyrrolic compounds,benzocarbazoles,whose distributions also indicated that the Pauls Valley Woodford oils came from deeper part of the Anadarko Basin as the benzo-[a]/([a]+[c])-carbazole ratios decrease eastwards.In more specific migration systems,although the pyrrolic compound indicators are potentially disturbed by the structural complexes,the general migration directions suggest that the studied oils in Pauls Valley Hunton uplift were sourced from the deep basin area,and migrate upwards in porous sediments due to the buoyancy.This study investigates the feasibility of using pyrrolic compounds to estimate relative migration distances and will aid in the interpretation of migration history by using the distribution of carbazole,alkylated carbazoles,benzocarbazoles isomers in the Anadarko and Ardmore Basin petroleum systems.
基金financially supported by Shanxi Province Natural Science Foundation of China(20210302123167)NSFC-Shanxi joint fund for coal-based low carbon(U1610223)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2021SX-TD006).
文摘Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry.The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in chemical engineering.Deep eutectic solvents (DESs) as a sustainable green separation solvent have been proposed for the separation of carbazole from model anthracene oil.In this research,three quaternary ammonium-based DESs were prepared using ethylene glycol (EG) as hydrogen bond donor and tetrabutylammonium chloride (TBAC),tetrabutylammonium bromide or choline chloride as hydrogen bond acceptors.To explore their extraction performance of carbazole,the conductor-like screening model for real solvents (COSMO-RS) model was used to predict the activity coefficient at infinite dilution (γ^(∞)) of carbazole in DESs,and the result indicated TBAC:EG (1:2) had the stronger extraction ability for carbazole due to the higher capacity at infinite dilution (C^(∞)) value.Then,the separation performance of these three DESs was evaluated by experiments,and the experimental results were in good agreement with the COSMO-RS prediction results.The TBAC:EG (1:2) was determined as the most promising solvent.Additionally,the extraction conditions of TBAC:EG (1:2) were optimized,and the extraction efficiency,distribution coefficient and selectivity of carbazole could reach up to 85.74%,30.18 and 66.10%,respectively.Moreover,the TBAC:EG (1:2) could be recycled by using environmentally friendly water as antisolvent.In addition,the separation performance of TBAC:EG (1:2) was also evaluated by real crude anthracene,the carbazole was obtained with purity and yield of 85.32%,60.27%,respectively.Lastly,the extraction mechanism was elucidated byσ-profiles and interaction energy analysis.Theoretical calculation results showed that the main driving force for the extraction process was the hydrogen bonding ((N–H...Cl) and van der Waals interactions (C–H...O and C–H...π),which corresponding to the blue and green isosurfaces in IGMH analysis.This work presented a novel method for separating carbazole from crude anthracene oil,and will provide an important reference for the separation of other high value-added products from coal tar.
基金supported by the National Natural Science Foundation of China(Nos.22271046,21971038,21975044)the Fujian Provincial Department of Science and Technology(No.2019L3004)the Foundation of National Key Laboratory of Human Factors Engineering(No.HFNKL2023W04)。
文摘Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In this work,the first HOF for organic acid sensing is reported by constructing a multiplepyridine carbazole-based dense HOF,namely HOF-FJU-206,from a tripyridine-carbazole molecular 3,6-bis(pyridin-4-yl)-9-(4-(pyridin-4-yl)phenyl)-9H-carbazole(CPPY)with carbazole center for luminescence,pyridyl sites for its responsive of hydrogen proton,and narrow channels in the dense framework for the diffusion of hydrogen protons.HOF-FJU-206 exhibits differential responsively fluorescence sensing and recovery properties to formic,acetic,and propionic acids with different molecular sizes and p Kavalue(acid dissociation constant).The dissociation degree of various acids can be determined by analyzing the slope of changes in both peak wavelength and intensity of in-situ fluorescence,which easily enables the dual-corrective recognition of different acids.The varying degree of protonation at pyridine sites is proved to be the reason for differential sensing of various acids,as demonstrated by1H NMR spectra,X-ray photoelectron spectroscopy(XPS)characterization,and modeling studies.
文摘A SPE/GC-MS method for separation and determination of carbazoles in crude oil was developed.Alumina and silicic acid solid-phase extraction(SPE) columns were used to separate resin from crude oil and neutral nitrogen compounds from nitrogen riched resin.Carbazole and its alkylation series were quantitatively analysed by use of deuterate carbazole as an internal standard and the 9-benzocarbazole as an recovery rate standard.The modified method was very suitable for batch processing in organic geochemistry owing to its low cost,time saving,environmental friendliness.
文摘AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) and pancreatic stress kinase activity was determined. Parameters to assess pancreatitis included trypsin, amylase, lipase, pancreatic weight and histology. RESULTS: JNK inhibition with CEP1347 ameliorated pancreatitis, reducing pancreatic edema. In contrast, p38 inhibition with SB203580 aggravated pancreatitis with higher trypsin levels and, with induction of acinar necrosis not normally found after cerulein hyperstimulation. Simultaneous treatment with both CEP1347 and SB203580 mutually abolished the effects of either compound on cerulein pancreatitis. CONCLUSION: Stress kinases modulate pancreatitis differentially. JNK seems to promote pancreatitis development, possibly by supporting inflammatory reactions such as edema formation while its inhibition ameliorates pancreatitis. In contrast, p38 may help reduce organ destruction while inhibition of p38 during induction of cerulein pancreatitis leads to the occurrence of acinar necrosis.
基金The National Natural Science Foundation of China(No.60678042)the Natural Science Foundation of Jiangsu Province(No.BK2006553)the Pre-Research Project of the National Natural Science Foundation supported by Southeast University(No.9207041399)
文摘Carbazole-core multi-branched chromophores 9-ethyl- 3, 6-bis （ 2- { 4- [ 5- （4-tert-butyl-phenyl） - [ 1, 3, 4 ] oxadiazol-2-yl ] - phenyl }-vinyl） -carbazole（3） and 9-ethyl-3-（ 2- {4-[ 5-（4-tert-butyl- phenyl） -[ 1, 3, 4 ] oxadiazol-2-yl ] -phenyl }-vinyl ） -carbazole （ 2 ） are synthesized through Wittig reaction and characterized by nuclear magnetic resonance（NMR）and infrared（IR）. The two- photon absorption properties of chromophores are investigated. These chromophores exhibit large two-photon absorption crosssections and strong blue two-photon excited fluorescence. The cooperative enhancement of two-photon absorption（TPA） in the multi-branched structures is observed. This enhancement is partly attributed to the electronic coupling between the branches. The electronic push-pull structures in the arm and their cooperative effects help the extended charge transfer for TPA.
文摘The direction of oil charges within a field in the Niger Delta, Nigeria was determined by the sum of differences ranking method of carbazole concentrations after ascertaining other possible geological constraints on their compositional variations. The principle is that the smaller the sum, the closer the well to the source kitchen. The approach makes use of carbazoles' interaction with the matrix, which leads to a reduction in their concentration with increasing distance from the source kitchen, allowing prediction of the charging direction. A wide range of compositional variations was observed for C1(806.72–2152.90 lg/g) and C2(767–2469.72 lg/g) carbazoles within the field. Based on these results, we inferred a filling pathway orientation from west to east. This suggests that the source kitchen—the most promising region for oil exploration—is located in the western part of the oil field.
