查看更多>>摘要：A new class of quinolizinium-based tunable pH fluorescent probes for cell imaging was developed.The probes showed turn"On"fluorescence response upon acidification brought by a modulation of photoinduced electron transfer(PET)from the N,N-dialkyl aniline substituent to the quinolizinium core skeleton.These novel PET-based pH fluorescent probes displayed tunable emission properties in between 478 and 509 nm.Also,the probes exhibited tunable pH responsiveness with pKa ranging from<2.1 to 6.1 contributed by the steric effect of N,N-dialkyl anilines.They were successfully applied to in vivo pH sensing in lysosome in live cells.
查看更多>>摘要：The rational construction and modulation of charge-transfer based fluorescence materials in host-guest systems by virtue of donor-acceptor interactions remains a challenge owing to the elaborate self-assembly process of acceptor and donor components.Taking into account the design principles of the host-guest system,a well-defined MOF with electron-deficient properties should be an ideal host for the building of charge-transfer based fluorescence materials.Herein,an electron-deficient MOF host,[Cd3(NDC)3(tpt)2(H2O)3](1)(H2NDC = 1,4-naphthalenedicarboxylic acid,tpt = 2,4,6-tri(4-pyridinyl)-1,3,5-triazine),and a corresponding series of host-guest materials lDguest(guest = phenanthrene for 2,anthracene for 3,pyrene for 4,triphenylene for 5)with charge-transfer based fluorescence were successfully fabricated via the donor-acceptor interactions.Profiting from the clear electron-rich guests to electron-deficient MOF framework charge transfer interactions,the host-guest materials exhibit color-tunable emission over a wide range by rational selection of guest molecules.Furthermore,the electronic structure calculations reveal that the multicolor emission of the newly synthesized MOF materials depends on the HOMO energy level/ionization potential of guests.This work provides a hopeful strategy for the assembly of various novel charge transfer fluorescent materials as potential luminophores.
查看更多>>摘要：In recent years,AIE(aggregation-induced emission)fluorophores have attracted great interest owing to their advantages in wide areas and many AIE fluorophores have be designed by combing conventional fluorophores with AIEgens that exhibiting AIE attributes.However,only few efficient AIEgens were developed.Here,novel dihydrobenzoquinolines(h-DHBQs 4a-e and f-DHBQ 5a),a new kind of AIEgens with strong AIE,are reported.DHBQs were synthesized by a catalyst-free multi-component reaction(MCR)in good overall yield and their optical properties were investigated through steady-state and transient fluorescence spectra,single-crystal diffraction,calculated HOMOs and LUMOs.It was found that DHBQs have these characteristics:a)strong AIE,that is,their fluorescence quantum yields lower than 4.1% in solutions,but high to 90.5% in crystals; b)efficient through-bond and-space conjugated nonaromatic central heterocycle; c)radiative-process-favored but non-radiative-decay-prevented self-assemblies; d)emissive excimers; and e)easily tunable fluorescence color.This work affords a new kind of AIEgens with excellent optical properties in solids and a strategy to develop AIEgens by constructing nonaromatic heterocycle using simple MCRs.
查看更多>>摘要：Photonic crystals are widely used in sensors,photocatalysts,remote communication,and optical computing on account of their unique photonic band gap and photonic localization.In the past decades,efficient visual detection of molecules and ions has been deeply studied through the combination of photonic crystals and different recognition technologies.Generally,the fabrication of molecular or ion recognition sensors involves the design of binding units for specific targets and signal units for different responses.Among many signal units,optical signal units are one of the most widely used in material recognition,ideally a visual readout.In this paper,recent advances of polymeric photonic crystals in the field of molecular recognition based on molecular imprinting,pH response,enzyme catalysis,and host-guest interaction are summarized and emphasized,and their future perspectives are also highlighted.
查看更多>>摘要：For tumor resection,the key step is to distinguish normal from tumor cells accurately.In this article,a lysosome targeting double site fluorescent probe T was reported for porcine pancreatic lipase(PPL)and hydrogen sulfide(H2S).In PBS solution,T could be hydrolyzed by PPL and emitted yellow fluorescence,but no fluorescence change could be observed by H2S only.While in the coexistence of PPL and H2S,a double site chemical reaction was activated,and blue fluorescence was found in the end.The concentration of H2S in some cancer cells is high enough to trigger this dual-site chemical reaction for T.This phenomenon can be repeated in cell experiments:T emits yellow fluorescence in normal cells(MPC)and blue fluorescence in cancer cells(HeLa and SMCC-7721).It illuminates a fact that a vast amount of H2S existed in these cancer cells.As a result,probe T could be used to distinguish cancer cells from normal cells with different fluorescence colors.
查看更多>>摘要：Eight nonlinear optical chromophores L1-2,M1-2,N1-2 and O1-2 based on the diethylamide bis(N,N-diethyl)aniline,bis(N-Ethyl-N-hydroxyethyl)aniline and bis(3-hydroxypiperidin)aniline donor and thiolated isophorone bridge were designed and synthesized.In particular,the bridge sections of the molecules were functionalized with tert-butyltrimethylsilane and tert-butyl(methyl)diphenylsilane isolation groups,respectively.All these eight chromophores exhibited high thermal stabilities with decomposition temperatures above 220 ℃.Density functional theory calculations indicated that the chromophores Ml-2,Nl-2 and 01-2 showed much larger hyperpolarizability than chromophores LI-2 with single donor due to the double donors structure.A large r33 value(198 p.m./V)and poling efficiency(2.03 ± 0.09 nm~2/V2)at 1310 nm have been achieved for polymer films containing chromophores N2 which was much larger than the value(104 p.m./V and 1.03 ± 0.05 nm~2/V2)of chromophore L2 with single donor.The reasonable design of these double donors can effectively improve the electron donating ability of donors and be applied to advanced organic nonlinear materials.
查看更多>>摘要：Artificial Intelligence(AI)is an interdisciplinary research line that aims to devise intelligent machines.Chemi Artificial Intelligence(CAI)focuses on designing intelligent chemical systems,primarily in wetware.This w<shows that intelligent chemical systems can be implemented by devising neural surrogates that,by interplayl can give rise to synchronization phenomena analogous to those of real neurons in the brain.When the sign employed in the communication are UV-visible radiations,the artificial neuron models can be implemen through photochromic and luminescent compounds,as this work demonstrates.Furthermore,this article scribes how photochromic and luminescent materials contribute to processing Fuzzy logic,which is a good mo of human power to compute by using words.Perspectives on how photoswitchable materials will be employee further developments of CAI are outlined.
查看更多>>摘要：We synthesized a diphenylamine modified pyrene derivative,4,9-diisopropyl-N,N,N/,N/-tetrakis-(4-methyl-biphenyl-3-yl)-pyrene-1,6-diamine(DITBDAP),and successfully applied it to deep-blue organic light-emitting diodes(OLEDs).The DITBDAP-based top-emitting OLED was featured by a high maximum external quantum efficiency(EQE_(max))of 20.6%,an extremely low CIEy(Commission International de L'Eclairage coordinates)of 0.04,a narrow full-width at half maximum of 16 nm,and a long lifetime of 250 h.We chose 6,12-bis[6-trime-thylphenyl)]amino5-trimethylphenyl)] amino] pyrene(Bmpac)as the comparison material due to its similar structure to DITBDAP.The DITBDAP-based bottom-emitting OLED showed a better performance compared to that of the Bmpac-based OLED,with the T_(95)lifetime(time to 95% of the initial luminance of 3000 cd m~(-2))of 250 h,which was more than twice that of the Bmpac-based OLED.In addition,the efficiency roll-off was extremely low at high brightness,which were 1% at 1100 cd m~(-2)and 5% at 3200 cd m~(-2).The synthesized DITBDAP has realized highly efficient and long-lifetime deep-blue OLEDs with the EQE up to 20.6% and CIEy as low as 0.04.
查看更多>>摘要：Carboxylesterase(CEs)are a kind of liver-synthesized esterase and play a great role in various physiological activities such as drug metabolism and transport processes.Accurate detection of their activity through near-infrared(NIR)fluorescence probe with large Stokes shift is still needed to investigate their biological function and diagnose related disease in vivo.In present study,a new"off-on"fluorescent probe(ZM-1)was constructed with large Stokes shift(160 nm).ZM-1 could be used to detect CEs with a bright NIR emission in a concentration dependent and time-dependent manner.The detection line of ZM-1 is as low as 0.287 × 10~3 U/mL.Moreover,ZM-1 possessed high selectivity and low toxicity.ZM-1 exhibited good optical performance to track CEs activity in cells and monitor the change of CEs activity on 5-Fu-induced model,indicating its good cell membrane permeability and precise detection character.More importantly,ZM-1 was successfully used to in situ image CEs activity in vivo.These studies suggest that probe ZM-1 has potential applicable valuation for CEs detection in living bio-systems and CEs-related disease diagnose.
查看更多>>摘要：In this work,two compounds with aggregation-induced emission(AIE)and thermally activated delayed fluorescence(TADF)properties(XT-T and XT-OT)which have the xanthone moiety as an electron withdrawing group were synthesized and studied.Both molecules exhibited the mechano-responsive luminescence(MRL)effect,in which a crystal of XT-OT could exhibit a bathochromic shift of 101 nm to achieve a wide-range emission transition from blue to yellow after grinding,compared to 34 nm for crystal XT-T.Such a high color-difference in the maximum emission peak was rarely reported in MRL materials.Analysis of crystal structures showed that small differences in structure could give rise to variable conformations and packing patterns in different aggregated states.The application of two compounds as light-emitting layers in organic light-emitting diodes(OLEDs)revealed the impact on device performance by their structural difference.The results presented here could provide a complementary strategy to design new multi-function materials.
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