The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties w...The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties were determined by polarizing optical microscopy（POM）,differential scanning calorimetry（DSC） and UV-visible spectrometry.The rod-shaped compound 4a having an odd number of carbon atoms in the alkyl chains exhibits nematic phase and SmA type phase whereas compound 4b having an even number of carbon atoms showed only nematic phase.Both fluorinecontaining compounds 4c and 4d showed only SmA type phases.The photoswitching properties of these compounds showed a rate of trans to cis isomerization ranging 19-20 s,whereas reverse process took around 230 min in solution.These materials may be ideal in the field of optically rewritable applications where both on and off rates should be crucial.展开更多
Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting ...Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only vip)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable vip further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.展开更多
Current efforts in materials science focus on developing efficient solid-state proton conductors for energy production and on achieving light-induced control of material properties at the molecular level.The convergen...Current efforts in materials science focus on developing efficient solid-state proton conductors for energy production and on achieving light-induced control of material properties at the molecular level.The convergence of these two aspects opens the way to entirely new functionalities.In this context,we present the synthesis,crystal structures,proton conductivity,and photomagnetic effect in two new CNbridged(H_(3)O)_(4){[Cu^(Ⅱ)(cyclam(COOH)_(2))]_(3)[M^(Ⅳ)(CN)_(8)]_(2)}Cl_(2)·10H_(2)O coordination complexes(M=Mo^(Ⅳ)(1),W^(Ⅳ)(2))incorporating dicarboxy-functionalized cyclam(cyclam(COOH)_(2)=6,13-dicarboxy-1,4,8,14-tetraazacyclotetradecane).1 and 2 crystallize in the P1¯space group,are isostructural,and consist of linear pentanuclear{Cu_(3)^(Ⅱ)M_(2)^(Ⅳ)}^(2-)molecules with Cu^(Ⅱ)complexes linked by[M^(Ⅳ)(CN)_(8)]^(4-)anions.Due to the presence of protic COOH groups,H_(3)O+cations,and an extensive network of hydrogen bonds,the compounds 1 and 2 exhibit proton conductivity of 3.88(7)×10^(-5)S cm^(-1)and 1.02(1)×10^(-5)S cm^(-1)(298 K,95%RH),respectively.Activation energies of 0.49 eV(1)and 0.46 eV(2)suggest that proton relay occurs predominantly along the network of moderate-strength H-bonds according to the Grotthuss mechanism.Both compounds exhibit a photomagnetic response to irradiation with 450 nm light at 10 K,which is attributed to photoinduced transition from singlet(S=0)to triplet(S=1)spin-state of M^(Ⅳ)centers.The magnetic characteristics of irradiated materials indicate almost complete photoconversion,which activates magnetic superexchange between Cu^(Ⅱ)(S=1/2)and the photoexcited M^(Ⅳ)exhibiting significant zero-field splitting.The coexistence of electrical and switchable magnetic properties in compounds 1 and 2 positions Cu^(Ⅱ)-M^(Ⅳ)assemblies as promising platforms for photoswitchable spin-ionics.展开更多
Lanthanide-doped photon-avalanche(PA)upconversion(UC)nanoparticles(NPs),characterized by highly nonlinear optical response,have recently attracted tremendous interest for applications in many frontier areas such as su...Lanthanide-doped photon-avalanche(PA)upconversion(UC)nanoparticles(NPs),characterized by highly nonlinear optical response,have recently attracted tremendous interest for applications in many frontier areas such as super-resolution imaging[1],dynamic photoswitching[2],ultrasensitive optical sensing[3],and high-density optical memory and computing[4].Specifically,the large nonlinearities(N)of PA have fueled the development of low-cost,single-beam super-resolution imaging techniques,offering a√N-fold improvement in spatial resolution[5].Although PA NPs with N plateauing 60s have been developed through energy transfer engineering based on core/shell architecture[6],further enhancement remains challenging.展开更多
Photoswitchable catalysis provides a non-invasive strategy for dynamically controlling light-driven chemical energy conversion processes.The defining advantage of photoswitchable catalytic systems lies in their unique...Photoswitchable catalysis provides a non-invasive strategy for dynamically controlling light-driven chemical energy conversion processes.The defining advantage of photoswitchable catalytic systems lies in their unique dual capacity:i)spatiotemporal precision in resolving reactive species generation through optical addressing;and ii)adaptive multifunctionality enabling on-demand switching between distinct active phases,thereby suppressing competing pathways and eliminating undesired side reactions.展开更多
Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application p...Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application potential in information encryption,anti-counterfeiting,but remained challenging in improving the security.Herein,we described a self-erased time-resolved information encryption via using photoswitchable dual-color fluorescent polymeric nanoparticles(PDFPNs)containing two fluorescence dyes(blue and red)and photochromic spiroxazine derivatives.In view of the different thermo-induced isomerization rates of photochromic spiroxazine derivatives in different flexible substrates,the decoloration rate of PDFPNs can be programmatically tuned by regulating ratio between rigid polymer and flexible polymer.Therefore,after ultraviolet light(UV)irradiation,correct information could only be recognized in preestablished time during the self-erased process.Our results indicated that PDFPNs exhibited fast photo-responsibility(2 min),high fluorescence contrast,well-pleasing photo-reversibility(>20 times),and programmable thermo-responsiveness(24 s-6 h).We thus demonstrated their application in the selferased time-resolved information encryption and anti-counterfeiting with high security.展开更多
Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching devices.Herein,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism a...Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching devices.Herein,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism and multicolor upconversion properties from green,red to near infrared(NIR) emissions with increasing Yb concentrations.Reversible multiband upconversion modulations are achieved by alternating light(365 and 405 nm) or thermal stimuli.After 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21%(green),82.12%(red) and 77.38%(NIR) in the Y_(0.83)Er_(0.01)Tm_(0.01)NbO_(4):0.15 Yb sample.Besides,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide temperature range of 298-718 K.These results indicate that the Er^(3+)/Tm^(3+)/Yb^(3+) tri-doped YNbO_(4) materials can be a good candidate in optical switching and data storage applications.展开更多
For the main purpose of manipulating the functions of molecules, researchers have made great achievements on photoresponsive molecules using light as a trigger. Light has become a promising scientific tool due to it b...For the main purpose of manipulating the functions of molecules, researchers have made great achievements on photoresponsive molecules using light as a trigger. Light has become a promising scientific tool due to it being a clean and noninvasive external stimulant. By attachment of photoresponsive moieties to molecules, the biological activities of molecules can be attenuated by light activation. With wide applications of laser in life sciences, it will be possible to achieve high spatiotemporal resolution. In this review, we focus on photoresponsive nucleic acids for photomodulating gene expression with light activation. With incorporation of photoswitchable or photocleavable moieties, biological behaviors of nucleic acids are photoregulated reversibly or irreversibly. Recent development and applications of photoresponsive nucleic acid in vitro and in vivo have shown a very promising future for manipulation of specific functional genes or disease genes. We expect that photoresponsive nucleic acids will be powerful scientific tools for studying biological events as well as gene therapy agents for genetic diseases.展开更多
Photo-responsive azobenzene （ABZ） derivatives with different end groups （R） as photoswitchable molecules were employed to construct self-assembled monolayers （SAMs） on silicon substrate by using 3-glycidoxypropy...Photo-responsive azobenzene （ABZ） derivatives with different end groups （R） as photoswitchable molecules were employed to construct self-assembled monolayers （SAMs） on silicon substrate by using 3-glycidoxypropyltrimethoxysilane （GPTS） as the bridging molecules. The assembly process was optimized by changing various parameters, including the type and concentration of ABZ derivatives, reaction time, etc. The obtained SAMs were fully characterized and evaluated using UV spectroscopy, atomic force microscope （AFM）, elllipsometer, static contact angle and X-ray photoelectron spectroscopy （XPS）. It is found that the end group property of azobenzene derivatives is critical to the obtained SAMs＇ photoresponsive properties. Compared with hydrophobic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-CF3）, the hydrophilic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-COOH） show excellent reversible photoswitching performance with a large contact angle change of 35° under oDtimized process, and the SAMs are removable bv thermal treatment at 240 ℃ in air for onlv 5 min.展开更多
The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 a...The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 and H-Phe-Tyr-Ψ[CS-N]- Pro-Trp-Gly-NH_2 were studied by UV-vis absorption.The isomerization energy barriers of the two segments,Ac-Phe-Ψ[CS-NH]- D-Ala-NH_2 and Ac-Tyr-Ψ[CS-N]-Pro-NH_2 picked from the two peptides,were calculated using ab initio method.The cis isomer of CS-N is more stable than th...展开更多
The preparation and performance characterization of〈50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented.The nanocomposites were fabricated by means of a modifed min...The preparation and performance characterization of〈50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented.The nanocomposites were fabricated by means of a modifed miniemulsion polymerization process,in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix,respectively.The obtained nanocomposites with a high relative fluorescence quantum yield（Q）exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer.The stability of photomerocyanine was also improved.展开更多
Tetraphenylethene(TPE),a star building block with promising aggregationinduced emission,has received much interest.Given that its intramolecular Woodward-Hoffmann cyclic intermediate instantaneously converts back to t...Tetraphenylethene(TPE),a star building block with promising aggregationinduced emission,has received much interest.Given that its intramolecular Woodward-Hoffmann cyclic intermediate instantaneously converts back to the original state within several picoseconds,the essentially photochromic characteristic of TPE is little investigated.Achieving a visible photocyclization of TPE is still an unsolved issue and considered as the bottleneck in the further advancement of applications.We report a strategy of attaching carbonate ester onto the TPE skeleton(TPE-4C)to enhance TPE photocyclization stability.As demonstrated,the incorporated cholesteryloxycarbonyloxy substituents in TPE-4C can increase the energy barrier for cycloreversion,thereby exhibiting extremely thermal stability of photocyclic intermediate upon UV irradiation,prolonging its lifetime from 63 picoseconds to 46 s by 7.2×10^(11)-fold.The photoinduced cyclization of TPE-4C could be monitored with naked eyes,and the photocyclization/cycloreversion is achieved by turning on/off UV light along with a relative fatigue resistance.Encapsulation of TPE-4C into the liquid crystal can induce a striking phase transformation(achiral↔chiral),which can be applicable to encode optical information.Employing carbonate ester into the TPE unit plays a vital role in enhancing the unprecedented TPE photocyclization stability,providing a toolbox to allow TPE-based photocyclization to be visually monitored.展开更多
1.Introduction The introduction of photoswitches into the bioactive substances is the fundamental idea behind photopharmacology.Upon light irradiation,the drug activity can be spatiotemporally controlled by the photon...1.Introduction The introduction of photoswitches into the bioactive substances is the fundamental idea behind photopharmacology.Upon light irradiation,the drug activity can be spatiotemporally controlled by the photon-induced variety of photoswitch's structures or characteristics[1].However,some challenges are still faced in photopharmacology including phototoxicity and limited tissue penetration depth(about a few millimeters).展开更多
An interest in the fluorescent protein asFP595 is due to unexplained puzzles in its photophysical behavior. We report the results of calculations of structures, absorption, and emission bands in asFP595 by considering...An interest in the fluorescent protein asFP595 is due to unexplained puzzles in its photophysical behavior. We report the results of calculations of structures, absorption, and emission bands in asFP595 by considering model molecular clusters in the coordinate-locking scheme. Both trans and cis conformations of the anionic chromophore are considered. Equilibrium geometry coordinates on the ground potential energy surface were optimized in the density functional theory approaches by considering both large- and reduced-size clusters. The cluster size was reduced to locate positions of the minimum energy points on the excited-state potential surface by using the configuration interaction singles approach. Vertical excitation energies and oscillator strengths were computed by using the ZINDO method. We show that consideration of large clusters mimicking the protein-containing pocket is an essential issue to calculate positions of absorption and emission bands with the accuracy compatible to experiments.展开更多
The regulation of circularly polarized light(CPL)plays a crucial role in asymmetric catalysis and photonic functional devices.Photonic functional devices utilizing multi-responsive integrated chiral fluorescent photos...The regulation of circularly polarized light(CPL)plays a crucial role in asymmetric catalysis and photonic functional devices.Photonic functional devices utilizing multi-responsive integrated chiral fluorescent photoswitches(CFPSs)as core components exhibit enhanced CPL signal modulation capabilities.By strategically combining liquid crystals(LC)with novel CFPSs,we develop smart materials capable of diverse CPL modulation behaviors including photo-induced CPL“turn on”and pH-induced CPL“turn off”.For achieving this aiming,the newly synthesized CFPS named Switch-ADAE not only inherits the inherent photoresponsiveness of diarylethene(DAE)frameworks but also demonstrates pH-responsiveness through pyridine group incorporation.Furthermore,the cholesteric liquid crystal(CLC)system composed of Switch-ADAE and nematic LCs exhibits synergistic light/pH multi-responsiveness.Under UV/visible light illumination,this system enables reversible fluorescence and CPL signal on/off switching.The introduction of TFA/TEA into the closed-ring isomer further facilitates reversible redshifts in fluorescence wavelengths and CPL signal deactivation,thereby establishing a dual-regulation CPL modulation system.Finally,a multi-mode information encryption system leveraging pH-responsive modulation and CPL compensation in CLC systems doped with Switch-ADAE.This proof-of-concept demonstrates the potential of such hybrid materials in developing advanced secure communication technologies and high-density information storage solutions.展开更多
Dynamic photoprogramming of paintable liquid crystal photonic devices with multi-stability shows practical application in smart soft materials and responsive optics.However,there exist three key challenges that limit ...Dynamic photoprogramming of paintable liquid crystal photonic devices with multi-stability shows practical application in smart soft materials and responsive optics.However,there exist three key challenges that limit their development:achieving precise paintability with controllable viscosity and resolution,maintaining well-ordered liquid crystal photonic structures,and enabling multi-stable photoresponsive behavior.Here,we address these limitations by incorporating an intrinsic photoswitch into a cellulose-based liquid crystal system,further constructing a unique paintable helical photonic architecture featuring both multi-stability and dynamic light-actuation.The intrinsic chiral photoswitch enables multi-stable modulation of helical pitch,while optimized viscosity restrains the remarkable fluidity of traditional liquid crystal systems and matches proper surface anchoring,thereby allowing for paintability and programming of a photonic device.The cutting-edge single-step painting enables highly efficient,large-area and welldefined patterning of helical architectures on diverse flexible substrates,thereby promoting prospective applications in anti-counterfeiting,information encryption,and smart window-film.This strategy establishes a robust and versatile foundation that integrates practical explorations in soft matter photonics with state-of-the-art engineering applications,such as multifunctional interactive optical information systems and advanced intelligent flexible sensors.展开更多
Metal complexes containing organic photoswitches are capable of modulating the steric and electronic environment around the metal center through photoisomerization,enabling their use in photoswitchable catalysis.Herei...Metal complexes containing organic photoswitches are capable of modulating the steric and electronic environment around the metal center through photoisomerization,enabling their use in photoswitchable catalysis.Herein,we design a new class of photoswitchable tripodal tetradentate ligands L1-L3 that can readily form air-stable Cu(Ⅰ)complexes(C1-PF_(6),C1-BF_(4),C2,C3).The design strategy integrates flexible spacers and phenylazopyrazole units in the same ligand framework that ensures efficient photoisomerization and sustained stability of the photoswitched state.The complexes were screened for catalyzing the CuAAC reaction between alkynes and azides and C1-PF_(6)was identified as a catalyst capable of exerting temporal control over the reaction through photoisomerization.Based on the optimized conditions and the substrate scope,the ZZZ(photoswitched)form of complex C1-PF_(6)exhibits substantially improved catalytic performance compared to its EEE(native)form.In this article,we describe detailed experimental and computational investigations aimed at understanding how photoisomerization regulates the catalytic activity of Cu(Ⅰ)complexes of arylazopyrazole-based tripodal tetradentate ligands.展开更多
A new dithienylperfluorocyclopentene–acetylide ligand(L2o)appended with a triarylamine moiety was used to synthesize two ruthenium(II)complexes with a photoswitchable electronic interaction between inorganic(Ru)and o...A new dithienylperfluorocyclopentene–acetylide ligand(L2o)appended with a triarylamine moiety was used to synthesize two ruthenium(II)complexes with a photoswitchable electronic interaction between inorganic(Ru)and organic(triarylamine)redox centres.展开更多
Lanthanide molecular nanomagnets featuring reversible photoresponsive characteristics and photomediated magnetic behavior are highly appealing for developing next-generation optics and memory devices though the ration...Lanthanide molecular nanomagnets featuring reversible photoresponsive characteristics and photomediated magnetic behavior are highly appealing for developing next-generation optics and memory devices though the rational assembly of such materials remains elusive.Herein,we demonstrate a stepwise approach,which employs a photochromic dysprosium-viologen compound{[Dy(ipbp)_(2)(H_(2)O)3]·NO_(3)·2H_(2)O}n(1)(H_(2)ipbp·Cl=(1-(3,5-dicarboxyphenyl)-4,4’-bipyridinium chloride))as the building block and 2,5-pyrazinedicarboxylate dianions(2,5-pzdc2-)as bridges,giving rise to a new framework{[Dy(ipbp)_(2)(2,5-pzdc)0.5(H_(2)O)]·5H_(2)O}n(2)exhibiting a photochromic effect and slow magnetic relaxation under a zero dc field.This finding is notable and exciting,as the starting compound 1 shows no magnetic relaxation on its own.The ab initio calculations demonstrate that by replacing water molecules at the equatorial plane in 1 with the 2,5-pzdc2-bridge,the longer Dy-N bond length and the less charged pyrazine nitrogen atom result in a weaker equatorial field strength,and the coordination geometry around the Dy^(3+)ion in 2 is thus closer to the ideal triangular dodecahedral geometry than in 1,leading to stronger axial magnetic anisotropy of the Dy^(3+)ion and switch-on of slow magnetic relaxation under a zero dc field.Further magnetic analysis of compound 2 before and after UV light irradiation reveals the weak ferromagnetic coupling between the photogenerated radicals and the Dy^(3+)ions,a slight inhibition of quantum tunnelling of magnetization,as well as a modest enhancement of the energy barrier for the slow magnetic relaxation,highlighting the photomodulation of the dynamic magnetic behavior.展开更多
Developing new responsive materials whose physico-chemical properties can be controlled and tailored by external stimuli is fundamental for many modern technologies.In this framework,3D-printable photochromic material...Developing new responsive materials whose physico-chemical properties can be controlled and tailored by external stimuli is fundamental for many modern technologies.In this framework,3D-printable photochromic materials and systems for all-optical data processing might enable remote addressing,by optical control of their response with high spatiotemporal accuracy,thus supporting the development of new computing and sensing platforms with multidimensional fashion.Here,we introduce 3D-printable photochromic materials based on either a spiropyran molecular system or a diarylethene derivative shaped by digital light processing.Dynamically controlling transmitted light by the intensity and sequence of incoming signals,these materials exhibit robust photoswitching cycles,long-term optically-textured information storage,and are used in 3D printed devices capable of all-optical arithmetic and logic processing.These compounds and devices open a route to new 3D all-organic all-optical computing platforms,and to new schemes and architectures for advanced microscopy,sensing,and physical intelligence.展开更多
基金supported by UMP Research(No.RDU 100338)RAGS(No.RDU131408)
文摘The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties were determined by polarizing optical microscopy（POM）,differential scanning calorimetry（DSC） and UV-visible spectrometry.The rod-shaped compound 4a having an odd number of carbon atoms in the alkyl chains exhibits nematic phase and SmA type phase whereas compound 4b having an even number of carbon atoms showed only nematic phase.Both fluorinecontaining compounds 4c and 4d showed only SmA type phases.The photoswitching properties of these compounds showed a rate of trans to cis isomerization ranging 19-20 s,whereas reverse process took around 230 min in solution.These materials may be ideal in the field of optically rewritable applications where both on and off rates should be crucial.
基金We thank Top-Notch Talents Program of Henan Agricultural University(No.30501049)Project supported by the Science and Technology Department of Henan Province(No.212102310332)the Merit Funding for the Oversea Staff of Henan Province for financial support.
文摘Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only vip)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable vip further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.
基金financed by the National Science Centre of Poland with grant no.2020/39/D/ST5/02387The study was conducted using research infrastructure funded by the European Union in the framework of the Smart Growth Operational Programme,Measure 4.2Grant No.POIR.04.02.00-00-D001/20,“ATOMIN 2.0-Center for materials research on ATOMic scale for the INnovative economy”.
文摘Current efforts in materials science focus on developing efficient solid-state proton conductors for energy production and on achieving light-induced control of material properties at the molecular level.The convergence of these two aspects opens the way to entirely new functionalities.In this context,we present the synthesis,crystal structures,proton conductivity,and photomagnetic effect in two new CNbridged(H_(3)O)_(4){[Cu^(Ⅱ)(cyclam(COOH)_(2))]_(3)[M^(Ⅳ)(CN)_(8)]_(2)}Cl_(2)·10H_(2)O coordination complexes(M=Mo^(Ⅳ)(1),W^(Ⅳ)(2))incorporating dicarboxy-functionalized cyclam(cyclam(COOH)_(2)=6,13-dicarboxy-1,4,8,14-tetraazacyclotetradecane).1 and 2 crystallize in the P1¯space group,are isostructural,and consist of linear pentanuclear{Cu_(3)^(Ⅱ)M_(2)^(Ⅳ)}^(2-)molecules with Cu^(Ⅱ)complexes linked by[M^(Ⅳ)(CN)_(8)]^(4-)anions.Due to the presence of protic COOH groups,H_(3)O+cations,and an extensive network of hydrogen bonds,the compounds 1 and 2 exhibit proton conductivity of 3.88(7)×10^(-5)S cm^(-1)and 1.02(1)×10^(-5)S cm^(-1)(298 K,95%RH),respectively.Activation energies of 0.49 eV(1)and 0.46 eV(2)suggest that proton relay occurs predominantly along the network of moderate-strength H-bonds according to the Grotthuss mechanism.Both compounds exhibit a photomagnetic response to irradiation with 450 nm light at 10 K,which is attributed to photoinduced transition from singlet(S=0)to triplet(S=1)spin-state of M^(Ⅳ)centers.The magnetic characteristics of irradiated materials indicate almost complete photoconversion,which activates magnetic superexchange between Cu^(Ⅱ)(S=1/2)and the photoexcited M^(Ⅳ)exhibiting significant zero-field splitting.The coexistence of electrical and switchable magnetic properties in compounds 1 and 2 positions Cu^(Ⅱ)-M^(Ⅳ)assemblies as promising platforms for photoswitchable spin-ionics.
基金the National Natural Science Foundation of China(Nos.12474418,U22A20398,22135008)the Natural Science Foundation of Fujian Province(No.2024J010038).
文摘Lanthanide-doped photon-avalanche(PA)upconversion(UC)nanoparticles(NPs),characterized by highly nonlinear optical response,have recently attracted tremendous interest for applications in many frontier areas such as super-resolution imaging[1],dynamic photoswitching[2],ultrasensitive optical sensing[3],and high-density optical memory and computing[4].Specifically,the large nonlinearities(N)of PA have fueled the development of low-cost,single-beam super-resolution imaging techniques,offering a√N-fold improvement in spatial resolution[5].Although PA NPs with N plateauing 60s have been developed through energy transfer engineering based on core/shell architecture[6],further enhancement remains challenging.
基金supported by the Qingdao Natural Science Foundation(23-2-1250-zyyd-jch)the National Natural Science Foundation of China(52173204)Cultivation Plan of Young Innovative Talents in Colleges and Universities of Shandong Province(2022KJ154)。
文摘Photoswitchable catalysis provides a non-invasive strategy for dynamically controlling light-driven chemical energy conversion processes.The defining advantage of photoswitchable catalytic systems lies in their unique dual capacity:i)spatiotemporal precision in resolving reactive species generation through optical addressing;and ii)adaptive multifunctionality enabling on-demand switching between distinct active phases,thereby suppressing competing pathways and eliminating undesired side reactions.
基金financially supported by the National Key R&D Program of China(Nos.2023YFB3812400,2023YFB3812403)National Natural Foundation of China(Nos.52273206,52350233)+1 种基金Hunan Provincial Natural Science Foundation(No.2021JJ10029)Huxiang High-level Talent Gathering Project(No.2022RC4039).
文摘Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application potential in information encryption,anti-counterfeiting,but remained challenging in improving the security.Herein,we described a self-erased time-resolved information encryption via using photoswitchable dual-color fluorescent polymeric nanoparticles(PDFPNs)containing two fluorescence dyes(blue and red)and photochromic spiroxazine derivatives.In view of the different thermo-induced isomerization rates of photochromic spiroxazine derivatives in different flexible substrates,the decoloration rate of PDFPNs can be programmatically tuned by regulating ratio between rigid polymer and flexible polymer.Therefore,after ultraviolet light(UV)irradiation,correct information could only be recognized in preestablished time during the self-erased process.Our results indicated that PDFPNs exhibited fast photo-responsibility(2 min),high fluorescence contrast,well-pleasing photo-reversibility(>20 times),and programmable thermo-responsiveness(24 s-6 h).We thus demonstrated their application in the selferased time-resolved information encryption and anti-counterfeiting with high security.
基金Project supported by the National Natural Science Foundation of China(52062042,51802164)the Natural Science Foundation of Inner Mongolia(2020MS05044)。
文摘Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching devices.Herein,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism and multicolor upconversion properties from green,red to near infrared(NIR) emissions with increasing Yb concentrations.Reversible multiband upconversion modulations are achieved by alternating light(365 and 405 nm) or thermal stimuli.After 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21%(green),82.12%(red) and 77.38%(NIR) in the Y_(0.83)Er_(0.01)Tm_(0.01)NbO_(4):0.15 Yb sample.Besides,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide temperature range of 298-718 K.These results indicate that the Er^(3+)/Tm^(3+)/Yb^(3+) tri-doped YNbO_(4) materials can be a good candidate in optical switching and data storage applications.
基金State Key Laboratory of Natural and Biomimetic Drugs and Peking University(bmu2009137-121)
文摘For the main purpose of manipulating the functions of molecules, researchers have made great achievements on photoresponsive molecules using light as a trigger. Light has become a promising scientific tool due to it being a clean and noninvasive external stimulant. By attachment of photoresponsive moieties to molecules, the biological activities of molecules can be attenuated by light activation. With wide applications of laser in life sciences, it will be possible to achieve high spatiotemporal resolution. In this review, we focus on photoresponsive nucleic acids for photomodulating gene expression with light activation. With incorporation of photoswitchable or photocleavable moieties, biological behaviors of nucleic acids are photoregulated reversibly or irreversibly. Recent development and applications of photoresponsive nucleic acid in vitro and in vivo have shown a very promising future for manipulation of specific functional genes or disease genes. We expect that photoresponsive nucleic acids will be powerful scientific tools for studying biological events as well as gene therapy agents for genetic diseases.
基金financially supported by The Dow Chemical Company
文摘Photo-responsive azobenzene （ABZ） derivatives with different end groups （R） as photoswitchable molecules were employed to construct self-assembled monolayers （SAMs） on silicon substrate by using 3-glycidoxypropyltrimethoxysilane （GPTS） as the bridging molecules. The assembly process was optimized by changing various parameters, including the type and concentration of ABZ derivatives, reaction time, etc. The obtained SAMs were fully characterized and evaluated using UV spectroscopy, atomic force microscope （AFM）, elllipsometer, static contact angle and X-ray photoelectron spectroscopy （XPS）. It is found that the end group property of azobenzene derivatives is critical to the obtained SAMs＇ photoresponsive properties. Compared with hydrophobic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-CF3）, the hydrophilic compounds （4-（4＇-aminophenylazo） benzoic acid, ABZ-COOH） show excellent reversible photoswitching performance with a large contact angle change of 35° under oDtimized process, and the SAMs are removable bv thermal treatment at 240 ℃ in air for onlv 5 min.
基金supported by the grant from National Natural Science Foundation of China(No.30870526)
文摘The photoisomerization abilities of secondary thioxopeptide bond(CS-NH) and thioxo prolyl bond(CS-N) incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NH_2 and H-Phe-Tyr-Ψ[CS-N]- Pro-Trp-Gly-NH_2 were studied by UV-vis absorption.The isomerization energy barriers of the two segments,Ac-Phe-Ψ[CS-NH]- D-Ala-NH_2 and Ac-Tyr-Ψ[CS-N]-Pro-NH_2 picked from the two peptides,were calculated using ab initio method.The cis isomer of CS-N is more stable than th...
文摘The preparation and performance characterization of〈50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented.The nanocomposites were fabricated by means of a modifed miniemulsion polymerization process,in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix,respectively.The obtained nanocomposites with a high relative fluorescence quantum yield（Q）exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer.The stability of photomerocyanine was also improved.
基金supported by NSFC/China(21788102,21636002,21622602,21875143,21908146,and 21908060)Shanghai Municipal Science and Technology Major Project(2018SHZDZX03)+3 种基金Innovation Program of Shanghai Municipal Education Commission,Scientific Committee of Shanghai(15XD1501400)Programme of Introducing Talents of Discipline to Universities(B16017)China Postdoctoral Science Foundation(2019M651417)Innovation Research Foundation of Shenzhen(JCYJ20180507182229597).
文摘Tetraphenylethene(TPE),a star building block with promising aggregationinduced emission,has received much interest.Given that its intramolecular Woodward-Hoffmann cyclic intermediate instantaneously converts back to the original state within several picoseconds,the essentially photochromic characteristic of TPE is little investigated.Achieving a visible photocyclization of TPE is still an unsolved issue and considered as the bottleneck in the further advancement of applications.We report a strategy of attaching carbonate ester onto the TPE skeleton(TPE-4C)to enhance TPE photocyclization stability.As demonstrated,the incorporated cholesteryloxycarbonyloxy substituents in TPE-4C can increase the energy barrier for cycloreversion,thereby exhibiting extremely thermal stability of photocyclic intermediate upon UV irradiation,prolonging its lifetime from 63 picoseconds to 46 s by 7.2×10^(11)-fold.The photoinduced cyclization of TPE-4C could be monitored with naked eyes,and the photocyclization/cycloreversion is achieved by turning on/off UV light along with a relative fatigue resistance.Encapsulation of TPE-4C into the liquid crystal can induce a striking phase transformation(achiral↔chiral),which can be applicable to encode optical information.Employing carbonate ester into the TPE unit plays a vital role in enhancing the unprecedented TPE photocyclization stability,providing a toolbox to allow TPE-based photocyclization to be visually monitored.
文摘1.Introduction The introduction of photoswitches into the bioactive substances is the fundamental idea behind photopharmacology.Upon light irradiation,the drug activity can be spatiotemporally controlled by the photon-induced variety of photoswitch's structures or characteristics[1].However,some challenges are still faced in photopharmacology including phototoxicity and limited tissue penetration depth(about a few millimeters).
文摘An interest in the fluorescent protein asFP595 is due to unexplained puzzles in its photophysical behavior. We report the results of calculations of structures, absorption, and emission bands in asFP595 by considering model molecular clusters in the coordinate-locking scheme. Both trans and cis conformations of the anionic chromophore are considered. Equilibrium geometry coordinates on the ground potential energy surface were optimized in the density functional theory approaches by considering both large- and reduced-size clusters. The cluster size was reduced to locate positions of the minimum energy points on the excited-state potential surface by using the configuration interaction singles approach. Vertical excitation energies and oscillator strengths were computed by using the ZINDO method. We show that consideration of large clusters mimicking the protein-containing pocket is an essential issue to calculate positions of absorption and emission bands with the accuracy compatible to experiments.
基金supported by the National Natural Science Foundation of China(52073017,51773009,52403317)the High Performance Computing Platform of Beijing University of Chemical Technology。
文摘The regulation of circularly polarized light(CPL)plays a crucial role in asymmetric catalysis and photonic functional devices.Photonic functional devices utilizing multi-responsive integrated chiral fluorescent photoswitches(CFPSs)as core components exhibit enhanced CPL signal modulation capabilities.By strategically combining liquid crystals(LC)with novel CFPSs,we develop smart materials capable of diverse CPL modulation behaviors including photo-induced CPL“turn on”and pH-induced CPL“turn off”.For achieving this aiming,the newly synthesized CFPS named Switch-ADAE not only inherits the inherent photoresponsiveness of diarylethene(DAE)frameworks but also demonstrates pH-responsiveness through pyridine group incorporation.Furthermore,the cholesteric liquid crystal(CLC)system composed of Switch-ADAE and nematic LCs exhibits synergistic light/pH multi-responsiveness.Under UV/visible light illumination,this system enables reversible fluorescence and CPL signal on/off switching.The introduction of TFA/TEA into the closed-ring isomer further facilitates reversible redshifts in fluorescence wavelengths and CPL signal deactivation,thereby establishing a dual-regulation CPL modulation system.Finally,a multi-mode information encryption system leveraging pH-responsive modulation and CPL compensation in CLC systems doped with Switch-ADAE.This proof-of-concept demonstrates the potential of such hybrid materials in developing advanced secure communication technologies and high-density information storage solutions.
基金supported by National Key Research and Development Program of China(2022YFA1203700)Basic Science Center of National Natural Science Foundation(T2488302)+5 种基金National Natural Science Foundation of China(22305079,2233000296,92356301,22338006,61822504,22108076,62275081 and 62505085)Innovation Program of Shanghai Municipal Education Commission,Scientific Committee of Shanghai(15XD1501400 and 2021-01-07-00-02-E00107)Shanghai Municipal Science and Technology Major Project(21JC1401700)“Shuguang Program”of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(21SG29)Fellowship of China National Postdoctoral Program for Innovative Talents(BX20230125)Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(24CGA29),Shanghai Sailing Program(23YF1409000,24YF2709100),Postdoctoral Fellowship Program of CPSF(GZB20240218).
文摘Dynamic photoprogramming of paintable liquid crystal photonic devices with multi-stability shows practical application in smart soft materials and responsive optics.However,there exist three key challenges that limit their development:achieving precise paintability with controllable viscosity and resolution,maintaining well-ordered liquid crystal photonic structures,and enabling multi-stable photoresponsive behavior.Here,we address these limitations by incorporating an intrinsic photoswitch into a cellulose-based liquid crystal system,further constructing a unique paintable helical photonic architecture featuring both multi-stability and dynamic light-actuation.The intrinsic chiral photoswitch enables multi-stable modulation of helical pitch,while optimized viscosity restrains the remarkable fluidity of traditional liquid crystal systems and matches proper surface anchoring,thereby allowing for paintability and programming of a photonic device.The cutting-edge single-step painting enables highly efficient,large-area and welldefined patterning of helical architectures on diverse flexible substrates,thereby promoting prospective applications in anti-counterfeiting,information encryption,and smart window-film.This strategy establishes a robust and versatile foundation that integrates practical explorations in soft matter photonics with state-of-the-art engineering applications,such as multifunctional interactive optical information systems and advanced intelligent flexible sensors.
基金DST Indo-Czech Republic Bilateral Scientific Research Cooperation,Ministry of Science and Technology,New Delhi,India(DST/INT/CZ/P-17/2019)the Science and Engineering Research Board(SERB),New Delhi for the financial support(CRG/2023/003861)+1 种基金SERB for funding(SB/SJF/2019-20/12,CRG/2022/001697)IISER Mohali for financial support,the departmental and central research facilities and other instruments(XRD,NMR,and HRMS including DST-FIST 400 MHz NMR facility,SR/FIST/CS-II/2019/94(C)TPN No.32545).
文摘Metal complexes containing organic photoswitches are capable of modulating the steric and electronic environment around the metal center through photoisomerization,enabling their use in photoswitchable catalysis.Herein,we design a new class of photoswitchable tripodal tetradentate ligands L1-L3 that can readily form air-stable Cu(Ⅰ)complexes(C1-PF_(6),C1-BF_(4),C2,C3).The design strategy integrates flexible spacers and phenylazopyrazole units in the same ligand framework that ensures efficient photoisomerization and sustained stability of the photoswitched state.The complexes were screened for catalyzing the CuAAC reaction between alkynes and azides and C1-PF_(6)was identified as a catalyst capable of exerting temporal control over the reaction through photoisomerization.Based on the optimized conditions and the substrate scope,the ZZZ(photoswitched)form of complex C1-PF_(6)exhibits substantially improved catalytic performance compared to its EEE(native)form.In this article,we describe detailed experimental and computational investigations aimed at understanding how photoisomerization regulates the catalytic activity of Cu(Ⅰ)complexes of arylazopyrazole-based tripodal tetradentate ligands.
基金financially supported from the 973 project from MSTC(2014CB845603)the NSF of China(21390392,21473201,U1405252,21531008,21303204 and 21502193)+1 种基金the Natural Science Foundation of Fujian Province(2013J05036)the CAS/SAFEA International Partnership Program for Creative Research Teams,and the Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDB20000000.DJ acknowledges the support of the ERC program in the framework of the Marches-278845 grant.
文摘A new dithienylperfluorocyclopentene–acetylide ligand(L2o)appended with a triarylamine moiety was used to synthesize two ruthenium(II)complexes with a photoswitchable electronic interaction between inorganic(Ru)and organic(triarylamine)redox centres.
基金supported by the National Natural Science Foundation of China(no.21671024 and 22271020).
文摘Lanthanide molecular nanomagnets featuring reversible photoresponsive characteristics and photomediated magnetic behavior are highly appealing for developing next-generation optics and memory devices though the rational assembly of such materials remains elusive.Herein,we demonstrate a stepwise approach,which employs a photochromic dysprosium-viologen compound{[Dy(ipbp)_(2)(H_(2)O)3]·NO_(3)·2H_(2)O}n(1)(H_(2)ipbp·Cl=(1-(3,5-dicarboxyphenyl)-4,4’-bipyridinium chloride))as the building block and 2,5-pyrazinedicarboxylate dianions(2,5-pzdc2-)as bridges,giving rise to a new framework{[Dy(ipbp)_(2)(2,5-pzdc)0.5(H_(2)O)]·5H_(2)O}n(2)exhibiting a photochromic effect and slow magnetic relaxation under a zero dc field.This finding is notable and exciting,as the starting compound 1 shows no magnetic relaxation on its own.The ab initio calculations demonstrate that by replacing water molecules at the equatorial plane in 1 with the 2,5-pzdc2-bridge,the longer Dy-N bond length and the less charged pyrazine nitrogen atom result in a weaker equatorial field strength,and the coordination geometry around the Dy^(3+)ion in 2 is thus closer to the ideal triangular dodecahedral geometry than in 1,leading to stronger axial magnetic anisotropy of the Dy^(3+)ion and switch-on of slow magnetic relaxation under a zero dc field.Further magnetic analysis of compound 2 before and after UV light irradiation reveals the weak ferromagnetic coupling between the photogenerated radicals and the Dy^(3+)ions,a slight inhibition of quantum tunnelling of magnetization,as well as a modest enhancement of the energy barrier for the slow magnetic relaxation,highlighting the photomodulation of the dynamic magnetic behavior.
基金funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program(grant agreement No.682157,“xPRINT”)the Italian Minister of University and Research PRIN 2017PHRM8X project(“3D-Phys”)funding from the project“MAD-La metamorfosi Additiva del Design”(PON‘Ricerca e Innovazione 2014-2020,ARS01_00717).
文摘Developing new responsive materials whose physico-chemical properties can be controlled and tailored by external stimuli is fundamental for many modern technologies.In this framework,3D-printable photochromic materials and systems for all-optical data processing might enable remote addressing,by optical control of their response with high spatiotemporal accuracy,thus supporting the development of new computing and sensing platforms with multidimensional fashion.Here,we introduce 3D-printable photochromic materials based on either a spiropyran molecular system or a diarylethene derivative shaped by digital light processing.Dynamically controlling transmitted light by the intensity and sequence of incoming signals,these materials exhibit robust photoswitching cycles,long-term optically-textured information storage,and are used in 3D printed devices capable of all-optical arithmetic and logic processing.These compounds and devices open a route to new 3D all-organic all-optical computing platforms,and to new schemes and architectures for advanced microscopy,sensing,and physical intelligence.
