Non-alcoholic fatty liver disease(NAFLD) is the leading cause of liver disease in the Western world and is closely associated with metabolic syndrome,which includes hypertension,central obesity,dyslipidemia and insuli...Non-alcoholic fatty liver disease(NAFLD) is the leading cause of liver disease in the Western world and is closely associated with metabolic syndrome,which includes hypertension,central obesity,dyslipidemia and insulin resistance.NAFLD includes a wide spectrum of liver alterations,ranging from simple hepatic steatosis to variable degrees of fibrosis,cirrhosis and even hepatocellular carcinoma.Although the etiology and progression of the disorder remain poorly understood,insulin resistance is considered to play a pivotal role in the pathogenesis.Insulin sensitizers such as biguanides,thiazolidinediones(TZDs),glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase 4 inhibitors have been studied as therapeutic approaches for NAFLD in recent years.Metformin improves insulin sensitivity and serum alanine transaminase and aspartate transaminase(ALT/AST) levels in the majority of subjects; however,it has no significant effect on liver histology.TZDs improve insulin sensitivity,serum ALT/ AST levels and histology in some cases,but there are some concerns about the safety of long-term therapy.Selection of appropriate patients for avoiding side effects and the treatment of underlying disease are themain points.These drugs are the best choice for the treatment of NAFLD in patients with type 2 DM who are also candidates for treatment with an insulin sensitizer.The present review provides an overview of insulin sensitizers in the treatment of NAFLD.展开更多
Narrow solar-light response range and rapid charges recombination are the main technical barriers in TiO_(2) photocatalysis technology.To overcome these restrictions,in this work we synthesized a novel binuclear gadol...Narrow solar-light response range and rapid charges recombination are the main technical barriers in TiO_(2) photocatalysis technology.To overcome these restrictions,in this work we synthesized a novel binuclear gadolinium(Ⅲ) coordination complex,[Gd_(2)(DPDB)_6(DMF)_6(H_(2)O_()2)](DPDB=[(4-dimethylamino)phenyldiazenyl] benzenesulfonate),which was used as an inorganic sensitizer for boosting the visible light-harvesting and quantum efficiency of TiO_(2) supported-reduced graphene oxide(rGO) nanocomposite.Crystal structure of [Gd_(2)(DPDB)_6(DMF)_6(H_(2)O)_(2)](Gd-CMP) was determined from single-crystal X-ray diffraction data,which indicates three-dimensional(3D) supramolecular architecture through hydrogen bonding and CH…π_(ph) interactions.The prepared nanohybrid(Gd-CMP/TG) reveals significantly enhanced visible-light-induced photocatalytic activity for degradation of acetaminophen(ACT).The complete removal of 10 mg/L ACT is achieved over Gd-CMP/TG,and the corresponding rate constant of ACT degradation of nanohybrid is 40-fold higher than that of bare TiO_(2).In prepared ternary nanohybrid,metal-coordination sensitizer(Gd-CMP) acts as an electron donor,and at the same time,rGO serves as an electron acceptor,and the synergistic effect between them efficiently enhances charges separation and inhibits e/h pair recombination in the hybridized species.The radical scavenger tests indicate that the photo-induced O_(2)^(-·) radicals dominate ACT degradation.On the basis of the experimental results and calculated energy of electronic levels,a possible mechanism for the improved photocatalytic activity is discussed.展开更多
Upconversion phosphors are known as a material system that can convert near-infrared light into visible/ultraviolet emissions by sequentially absorbing multiple photons. The studies on upconversion materials often use...Upconversion phosphors are known as a material system that can convert near-infrared light into visible/ultraviolet emissions by sequentially absorbing multiple photons. The studies on upconversion materials often use two rare earth(RE) ions as a sensitizer-activator pair. We investigated the influences on luminescence intensity depending on Cr-doping content(x) of hexagonal NaLu_(0.98-x)Cr_xF4 Er_(0.02)(x = 0-0.9)upconversion material by substituting Lu^(3+) ions with Cr^(3+)in the absence of Gd^(3+). The change in upconversion luminescence intensity appears with saddle-like shape. We suggest that Cr^(3+) ions play the dual role as a constituent in host lattice and a sensitizer in the upconversion process. Optimal conditions for gaining the strongest upconversion emission correspond to x = 0.3-0.5, where there are effective energy transfers between Cr^(3+) and Er^(3+) ions and Cr-Er dimers. Apart from these values, the emission intensity decreases rapidly which can be ascribed to the absence of multiple-photon absorption for the case of low Cr^(3+) contents, and to the coupling between Cr^(3+) and/or Er^(3+) ions for the case of high Cr^(3+)contents. Magnetization and electron-spin-resonant measurements were performed to understand the correlation between the optical and magnetic properties.展开更多
A polymer-bound photosensitizer was synthesized by the reaction of Merrifield resin with 9-anthracenemethanol in the presence of potassium hydride. The photoisomerization of trans-vitamin D3 to cis-vitamin D3 was car...A polymer-bound photosensitizer was synthesized by the reaction of Merrifield resin with 9-anthracenemethanol in the presence of potassium hydride. The photoisomerization of trans-vitamin D3 to cis-vitamin D3 was carried out with this polymer-bound photosensitizer in ethanol and toluene solutions. The experiment results demonstrate that this solid photosensitizer is efficient for the photoismerization and easy for separation from the reaction mixtures.展开更多
Although surgical resection and chemotherapy were widely applied in tumor therapy, the dysfunction of normal cells resulted in the side effects (such as anorexia, nausea). MW thermal therapy is a non-invasive anticanc...Although surgical resection and chemotherapy were widely applied in tumor therapy, the dysfunction of normal cells resulted in the side effects (such as anorexia, nausea). MW thermal therapy is a non-invasive anticancer strategy under the help of MW sensitizer, with the safety and higher efficacy. Zirconium metal-organic framework nanocubes (ZrMOF NCs) modified with polyethylene glycol, were prepared via one pot method and carbodiimide technique, resulting in their large specific surface area and porosity.Our results showed that non-ion-loaded ZrMOF NCs in 0.9% NaCl solution exhibited better heating effect,higher than that in pure water, due to the robust collision among the ions under MW irradiation. The in vivo experiments confirmed that ZrMOF-PEG NCs + MW group exhibited the higher temperature in the tumor region than that of only MW treatment, suggesting a better MW thermal therapeutic anticancer efficacy. This work provides a new preparation strategy of biosafety nanomaterial as MW sensitizer for enhancing MW thermal anticancer therapy.展开更多
The geometries, electronic structures, polarizabilities and hyperpolarizabilities, as well as the UV-Vis spectra of the two organic dye sensitizers containing bis-dimethylfluorenyl amino benzofuran were studied via de...The geometries, electronic structures, polarizabilities and hyperpolarizabilities, as well as the UV-Vis spectra of the two organic dye sensitizers containing bis-dimethylfluorenyl amino benzofuran were studied via density functional theory （DFT） and time-dependent DFT. The features of electronic absorption spectra were assigned on account of the agreement between the experiment and the calculations. The absorption bands in visible region are related to photoinduced electron transfer processes, and the dimethylfluorenyl amino benzo[b]furan groups are major chromophore that contributed to the sensitization of photo-to-current conversion. The role of vinylene group in geometry, electronic structure and spectra property is analyzed according to the comparative study of the dyes.展开更多
The geometry, electronic structure, polarizability and hyperpolarizability of dye sensitizer 3,4-bis[1-（carboxymethyl）-3-indolyl]-1H-pyrrole-2,5-dione （BIMCOOH） were studied using density functional theory （DFT）...The geometry, electronic structure, polarizability and hyperpolarizability of dye sensitizer 3,4-bis[1-（carboxymethyl）-3-indolyl]-1H-pyrrole-2,5-dione （BIMCOOH） were studied using density functional theory （DFT） with hybrid functional B3LYP, and the electronic absorption spectra were investigated using semi-empirical quantum chemical method ZINDO-1 and time-dependent DFT （TDDFT）. The results of natural bond orbital suggest that the natural charges of the dione, indole, and acetic groups are about 0.15e, -0.29e, and 0.44e, respectively. The calculated isotropic polarizability, polarizability anisotropy invariant and hyperpolarizability are 305.4, 188.3, and 1155.4 a.u., respectively. The electronic absorption spectral features in visible and near-UV region were assigned to the π→π^＊ transition due to the qualitative agreement between the experiment and the TDDFT calculations, and the transitions of the excited states 9-11 related to photoinduced intramolecular charge transfer processes. The analysis of electronic structure and UV-Vis absorption indicates that the indole groups primarily contributed sensitization of photo-to-currency conversion processes, and the interracial electron transfer between semiconductor TiO2 electrode and dye sensitizer BIMCOOH are electron injection processes from excited states of the dyes to the semiconductor conduction band.展开更多
White organic light-emitting diodes were fabricated by using a novel phosphorescence bis（1,2-diphenyl-1H-benzoimidazole）iridium（acetylacetonate）[（pbi）2Ir（acac）] as sensitizer and a fluorescent dye of 4- （dicy...White organic light-emitting diodes were fabricated by using a novel phosphorescence bis（1,2-diphenyl-1H-benzoimidazole）iridium（acetylacetonate）[（pbi）2Ir（acac）] as sensitizer and a fluorescent dye of 4- （dicyanomethylene）-2-t-butyl-6-（1,1,7,7-tetramethyljulolidyl-9-enyl）-4H-pyran （DCJTB） codoped into a carbazole polymer of poly（N-vinylcarbazole） （PVK）. Through characterizing the UV-Vis absorption spectra, the photoluminescence spectra of （pbi）2Ir（acac） and DCJTB, and the electroluminescence spectral properties of the WOLEDs, the energy transfer mechanisms of the codoped polymer system were deduced. The results demonstrate that the luminescent spectra with different intensity of （pbi）2Ir（acac） and DCJTB were co-existent in the EL spectra of the blended system, which is ascribed to an incomplete energy transfer process in the EL process. The efficient Forster and Dexter energy transfer between the host and the vips enabled a strong yellow emission from （pbi）2Ir（acac） and DCJTB, where （pbi）2Ir（acac） plays an important role as a phosphorescent sensitizer for DCJTB. With the blue emitting-layer of N,N＇-diphenyl-N,N＇-bis（1- naphthyl）（1,1＇-biphenyl）-4,4＇-diamine, the codoped system device achieved white emission. The codoped system showed that its Commissions Internationale de 1＇Eclairage coordinates were more independent of the variation of bias voltage than those of phosphorescent doped PVK systems.展开更多
A new method for the determination of utratrace silver(I) by near field thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromocresol green oxidized...A new method for the determination of utratrace silver(I) by near field thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromocresol green oxidized by sodium persulphate in the presence of a, a-bipy as activator and Triton X-100 as sensitizer. The linear range of this method is 0~1.6 ng穖L-1 of silver. The detection limit is 2?0-2 ng穖L-1. The method has been applied to the determination of silver in lead power and photographic paper with satisfactory results.展开更多
Four sensitizers of high purity were synthesized with high yield. Their structures were verified by IR spectra and elementary analysis. The tricomponent eutectoid point determined by thermal analysis and the optical d...Four sensitizers of high purity were synthesized with high yield. Their structures were verified by IR spectra and elementary analysis. The tricomponent eutectoid point determined by thermal analysis and the optical density determined by static and dynamic color development tests show that these sensitizers can lower the temperature and increase the rate of color development as well as enhance the optical .tensity when used in thermal sensitive materials.展开更多
The research on sensitizer for dye sensitized solar cells based on (metallo)porphyrin/phthalocyanine materials were reviewed, and experimental design and assembly method were advised. Latest progress and research stat...The research on sensitizer for dye sensitized solar cells based on (metallo)porphyrin/phthalocyanine materials were reviewed, and experimental design and assembly method were advised. Latest progress and research status of sensitizer dyes based on metalloporphyrins applied in dye sensitized solar cells was summarized. The preparation and construction of sensitizer electrodes and dye sensitized solar cells based on metal organic frameworks (MOFs) of (metallo)porphyrin/phthalocyanine were projected.展开更多
Dye-sensitized solar cells (DSSC) were fabricated with mango leaf dye extracts as natural dye sensitizers at pH value of 5.20 and temperature of 18.1°C. Methanol was used as dye-extracting solvent. DSSCs from dye...Dye-sensitized solar cells (DSSC) were fabricated with mango leaf dye extracts as natural dye sensitizers at pH value of 5.20 and temperature of 18.1°C. Methanol was used as dye-extracting solvent. DSSCs from dye extract of M. indica L. with KMnO4 electrolyte had the highest photocurrent density of 1.3 mA/cm2 and fill factor FF of 0.46 for the sun at its peak. Potassium permanganate (KMnO4) had a photocurrent density of 1.3 mA/cm2 and FF of 0.8 at sundown. Potassium Iodide (KI), Potassium Bromide (KBr) and Mercury Chloride (HgCl2) electrolytes had 0.2 mA/cm2, 0.08 mA/cm2 and 0.02 mA/cm2 photocurrent densities respectively. The fill factors of 0.09, 0.03 and 0.003 respectively for sun overhead while 0.08 mA/cm2, 0.01 mA/cm2 and 0.01 mA/cm2 were the values of photocurrent densities respectively at sundown. The fill factors were 0.02, 0.0006 and 0.003 respectively at sundown. The maximum power Pmax of the DSSCs were 0.5 mW/cm2, 0.10 mW/cm2, 0.01 mW/cm2 and 0.012 mW/cm2 respectively at 1300 h at 1630 h 0.9 mW/cm2, 0.14 mW/cm2, 0.005 mW/cm2 and 0.0015 mW/cm2 respectively.展开更多
Carbon quantum dots(CQDs)are emerging as the new-generation light absorber for solar energy conversion.However,the low photosensitization efficiency of CQDs is one of the current bottlenecks impeding their large-scale...Carbon quantum dots(CQDs)are emerging as the new-generation light absorber for solar energy conversion.However,the low photosensitization efficiency of CQDs is one of the current bottlenecks impeding their large-scale practical applications in photocatalysis.Therefore,developing a facile approach for the engineering and functionalization of CQDs-based composites to improve the photosensitization efficiency of CQDs is highly desirable.On account of the abundant functional groups,especially oxygen-containing functional groups such as carbonyl,carboxyl,and hydroxyl present on their surface,CQDs can be readily combined with various organic molecules or polymers as a surface passivation component to reduce the nonradioactive surface recombination of photo-generated charge carriers,thus enabling the CQDs to exhibit strong photoluminescence in the visible and near-infrared spectral regions.Consequently,polymer passivation has been demonstrated as an ideal strategy to make it accessible for improving the sensitization efficiency of CQDs in photocatalytic applications.Branched polyethylenimine(BPEI)is one of polymers that contains a high density of amine groups and exhibits high electron mobility,which can be used as an electron injection material at the interface of nanomaterials.Besides,the BPEI polymer with amino groups exhibiting positive charge has been utilized for designing heterogeneous catalysts by an electrostatic self-assembly strategy.Therefore,BPEI is expected to modify the surface of inorganic oxides semiconductor to enhance the photosensitization efficiency of CQDs under visible light.However,to date,the study in this regard has been still unavailable In this work,we developed a facile approach to engineer well-distributed CQDs via electrostatic interaction on BPEI passivated TiO2 composites(BTC)as photocatalysts.The BTC composites with an optimal loading of 5%(w,mass fraction)CQDs outperformed the TiO2/CQDs(TC)composite and referential BPEI/SiO2/CQDs(BSC)composites for the photoreduction of 4-nitroaniline under visible light irradiation.The structure of the fabricated BTC composites was systematically investigated by the combined use of structural and spectral characterizations,demonstrating that the photosensitizer CQDs contacted well with the BPEI modified TiO2 nanoparticles.The comparison characterizations revealed that BPEI facilitated the dissociation and transfer of excitons as an electron transfer channel.The as-prepared BTC composites benefited from the favorable interfacial contact and effective transfer of photo-generated charge carriers,and thus manifested superior photocatalytic activity to the TC composite.It is expected that this strategy would be extended to other wide band gap semiconductor photocatalyst systems and open up new possibilities in designing efficient CQDs-based semiconductor artificial light harvesting systems by interfacial optimization.展开更多
A new highly sensitive solid substrate room temperature phosphorimetry for the determination of trace titanium is proposed based on the sensitization of Triton X-100 to the SS-RTP intensity of 4,5-dibromophenylfluoron...A new highly sensitive solid substrate room temperature phosphorimetry for the determination of trace titanium is proposed based on the sensitization of Triton X-100 to the SS-RTP intensity of 4,5-dibromophenylfluorone-titanium complex adsorbed on the filter paper substrate modified by gelatin. When Triton X-100 was added into the luminescence system, the RTP intensity was raised 3 times stronger than that of the system without Triton X-100. The linear dynamic range of the new method is 0 64~3 2 fg/spot(0 4 μL) with a detection limit of 12 8 ag/spot, and the regression equation of the working curve is Δ I p =482 0+119 5 m Ti(Ⅳ) (fg/spot), the correlation coefficient r =0 9992, n =6. The phosphorescence lifetime( τ =0 85 ms) was also determined. The recoveries(and RSD) for the determinations of titanium in human hair and tea samples were 101 0%(3 0%) and 99 97%(4 2%), respectively.展开更多
Aromatic ketones,such as 9-fluorenone(9-FO),are known for their high intersystem crossing quantum yields(Φ_(ISC)≈1),rendering them highly valuable for photochemical reactions and dye-sensitized solar cells.However,t...Aromatic ketones,such as 9-fluorenone(9-FO),are known for their high intersystem crossing quantum yields(Φ_(ISC)≈1),rendering them highly valuable for photochemical reactions and dye-sensitized solar cells.However,their use as photosensitizers in biological contexts has been hindered by their low extinction coefficients,high excitation energies,and weak fluorescence.To address these limitations,we conjugated 9-FO with a fused-ring electron donor,resulting in an acceptor-donor-acceptor derivative IDT-9F.This strategy has successfully redshifted the absorption peak of 9-FO(380 nm)into the visible light range(498 nm)and significantly enhanced its light absorption capability(~310-fold)and fluorescence quantum yield(~100-fold).Furthermore,IDT-9F was encapsulated within pH-responsive nanoparticles using an acid-induced charge-reversal polymer as the amphiphilic matrix,and enabled fluorescence imaging-guided photodynamic inactivation of Gram-positive bacteria in acidic environment with a remarkable bacterial inhibition rate exceeding 99.9%.展开更多
Insulin resistance is a major risk factor for type 2 diabetes.AMP-activated protein kinase(AMPK)is a drug target in the improvement of insulin sensitivity.Several insulin-sensitizing medicines are able to activate AMP...Insulin resistance is a major risk factor for type 2 diabetes.AMP-activated protein kinase(AMPK)is a drug target in the improvement of insulin sensitivity.Several insulin-sensitizing medicines are able to activate AMPK through inhibition of mitochondrial functions.These drugs,such as metformin and STZ,inhibit ATP synthesis in mitochondria to raise AMP/ATP ratio in the.process of A MPK activation.However,chemicals that activate AMPK directly or by activating its upstream kinases have not been approved for treatment of type 2 diabetes in humans.In an early study,we reported that berberine inhibited oxygen consumption in mitochondria,and increased AMP/ATP ratio in cells.The observation suggests an indirect mechanism for AMPK activation by berberine.Berberine stimulates glycolysis for ATP production that offsets the cell toxicity after mitochondria inhibition.The study suggests that mitochondrial inhibition is an approach for AMPK activation.In this review article,literature is critically reviewed to interpret the role of mitochondria function in the mechanism of insulin resistance,which supports that mitochondria inhibitors represent a new class of AMPK activator.The inhibitors are promising candidates for insulin sensitizers.This review provides a guideline in search for small molecule AMPK activators in the drug discovery for type 2 diabetes.展开更多
Trivalent lanthanide(Ln2+)doped luminescent nanocrystals are promising for applications ranging from biosensor,lasing,super-resolution nanoscopy,information security and so on.Although the utility prospect is of great...Trivalent lanthanide(Ln2+)doped luminescent nanocrystals are promising for applications ranging from biosensor,lasing,super-resolution nanoscopy,information security and so on.Although the utility prospect is of great attractions,the light absorption of these lanthanide doped nanocrystals is inherently weak due to the electric dipole-forbidden 4f→4f transitions.Even worse,the quantum yields of upconverison nanocrystals are very low,which will unavoidably hinder their further applications.In a typical lanthanide luminescent nanosystem,both sensitizers as light absorption centers and activators as light emitting centers are necessary and important for desired luminescence properties.Among various sensitization systems,only Yb3+and Nd+are considered as the most efficient sensitizers.Thus,the corresponding excitation wavelengths are strictly limited around 980 and 808 nm.To enrich excitation wavelengths and boost luminescence intensity,exploring more sensitization units that possess larger absorption cross section,higher efficiency of energy transfer process and independent excitation is imperative and beneficial for the demands of different applications,such as broadened absorption in near infrared(NIR)region for higher conversion efficiency of solar cells,prolonged excitation wavelength to second near infrared windows region(NIR Ⅱ,1,000-1,700 nm)for in vivo fluorescence imaging with deeper tissue depth and higher spatial resolution,more orthogonal excitations and emissions to improve optical multiplexing,and so on.Therefore,in the review,we primarily conclude several major energy transfer mechanisms from sensitizers to activators.Then we present three kinds of sensitizers,including lanthanide ions,organic dyes and quantum dots(QDs),and introduce the newly designed sensitization system that allows us to exploit superior excitation wavelength and amplity luminescence intensity.Finally,several future challenges and opportunities for the sensitizing strategies are discussed in hope of directing and broadening the applications of lanthanide nanosystem.展开更多
Many sensitizers have not only photodynamic effects,but also sonodynamic effects.Therefore,the combination of sonodynamic therapy(SDT)and photodynamic therapy(PDT)using sensitizers for sonophotodynamic therapy(SPDT)pr...Many sensitizers have not only photodynamic effects,but also sonodynamic effects.Therefore,the combination of sonodynamic therapy(SDT)and photodynamic therapy(PDT)using sensitizers for sonophotodynamic therapy(SPDT)provides alternative opportunities for clinical cancer therapy.Although significant advances have been made in synthesizing new sensitizers for SPDT,few of them are successfully applied in clinical settings.The anti-tumor effects of the sensitizers are restricted by the lack of tumor-targeting specificity,incapability in deep intratumoral delivery,and the deteriorating tumor microenvironment.The application of nanotechnology-based drug delivery systems(NDDSs)can solve the above shortcomings,thereby improving the SPDT efficacy.This review summarizes various sensitizers as sono/photosensitizers that can be further used in SPDT,and describes different strategies for enhancing tumor treatment by NDDSs,such as overcoming biological barriers,improving tumor-targeted delivery and intratumoral delivery,providing stimuli-responsive controlled-release characteristics,stimulating anti-tumor immunity,increasing oxygen supply,employing different therapeutic modalities,and combining diagnosis and treatment.The challenges and prospects for further development of intelligent sensitizers and translational NDDSs for SPDT are also discussed.展开更多
Cancer remains one of the diseases with the highest incidence and mortality globally.Conventional treatment modalities have demonstrated threatening drawbacks including invasiveness,noncontrollability,and development ...Cancer remains one of the diseases with the highest incidence and mortality globally.Conventional treatment modalities have demonstrated threatening drawbacks including invasiveness,noncontrollability,and development of resistance for some,including chemotherapy,radiation,and surgery.Sono-photodynamic combinatorial therapy(SPDT)has been developed as an alternative treatment modality which offers a non-invasive and controllable therapeutic approach.SPDT combines the mechanism of action of sonodynamic therapy(SDT),which uses ultrasound,and photodynamic therapy(PDT),which uses light,to activate a sensitizer and initiate cancer eradication.The use of phthalocyanines(Pcs)as sensitizers for SPDT is gaining interest owing to their ability to induce intracellular oxidative stress and initiate toxicity under SDT and PDT.This review discusses some of the structural prerequisites of Pcs which may influence their overall SPDT activities in cancer therapy.展开更多
A variety of heteroleptic ruthenium sensitizers have been engineered and synthesized because of their higher light-harvesting efficiency and lower charge-recombination possibility than the well known homoleptic N3 dye...A variety of heteroleptic ruthenium sensitizers have been engineered and synthesized because of their higher light-harvesting efficiency and lower charge-recombination possibility than the well known homoleptic N3 dye. As such, a great deal of atten- tion has been focused on sensitizers with the general formula Ru（ancillary-ligand）（anchoring-ligand）（NCS）2, among which important examples are Ru（4,4＇-bis（5-hexylthiophen-2-yl）-2,2＇-bipyridine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （C101） and Ru（N-（4-butoxyphenyl）-N-2-pyridinyl-2-pyridinamine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （J13）. In order to simulate experimental conditions with different pH values, the photosensitizing processes of these sensitizers pos- sessing different degrees of deprotonation （2I-I, lit to OH） have been explored theoretically in this work. Their ground/excited state geometries, electronic structures and spectroscopic properties are first calculated using density functional theory （DFT） and time-dependent DFT （TDDFT）. The absorption and emission spectra of all the complexes in acetonitrile solution are also predicted at the TDDFT （B3LYP） level. The calculated results show that the ancillary ligand contributes to the molecular or- bital （MO） energy levels and absorption transitions. It is intriguing to observe that the introduction of a thiophene group into the ancillary ligand leads directly to the increased energy of the absorption transitions in the 380-450 nm region. The calcula- tions reveal that although deprotonation destabilizes the overall frontier MOs of the chromophores, it tends to exert a greater influence on the unoccupied orbitals than on the occupied orbitals. Consequently, an obvious blue shift was observed for the absorptions and emissions in going from 21-1, 1H to OH. Finally, the optimal degree of deprotonation for C101 and J13 has al- so been evaluated, which is expected to lead to further improvements in the performance of dye-sensitized solar cells （DSSCs） coated with such sensitizers.展开更多
文摘Non-alcoholic fatty liver disease(NAFLD) is the leading cause of liver disease in the Western world and is closely associated with metabolic syndrome,which includes hypertension,central obesity,dyslipidemia and insulin resistance.NAFLD includes a wide spectrum of liver alterations,ranging from simple hepatic steatosis to variable degrees of fibrosis,cirrhosis and even hepatocellular carcinoma.Although the etiology and progression of the disorder remain poorly understood,insulin resistance is considered to play a pivotal role in the pathogenesis.Insulin sensitizers such as biguanides,thiazolidinediones(TZDs),glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase 4 inhibitors have been studied as therapeutic approaches for NAFLD in recent years.Metformin improves insulin sensitivity and serum alanine transaminase and aspartate transaminase(ALT/AST) levels in the majority of subjects; however,it has no significant effect on liver histology.TZDs improve insulin sensitivity,serum ALT/ AST levels and histology in some cases,but there are some concerns about the safety of long-term therapy.Selection of appropriate patients for avoiding side effects and the treatment of underlying disease are themain points.These drugs are the best choice for the treatment of NAFLD in patients with type 2 DM who are also candidates for treatment with an insulin sensitizer.The present review provides an overview of insulin sensitizers in the treatment of NAFLD.
基金supported by grant No.98U587 from Abadan University of Medical Sciences。
文摘Narrow solar-light response range and rapid charges recombination are the main technical barriers in TiO_(2) photocatalysis technology.To overcome these restrictions,in this work we synthesized a novel binuclear gadolinium(Ⅲ) coordination complex,[Gd_(2)(DPDB)_6(DMF)_6(H_(2)O_()2)](DPDB=[(4-dimethylamino)phenyldiazenyl] benzenesulfonate),which was used as an inorganic sensitizer for boosting the visible light-harvesting and quantum efficiency of TiO_(2) supported-reduced graphene oxide(rGO) nanocomposite.Crystal structure of [Gd_(2)(DPDB)_6(DMF)_6(H_(2)O)_(2)](Gd-CMP) was determined from single-crystal X-ray diffraction data,which indicates three-dimensional(3D) supramolecular architecture through hydrogen bonding and CH…π_(ph) interactions.The prepared nanohybrid(Gd-CMP/TG) reveals significantly enhanced visible-light-induced photocatalytic activity for degradation of acetaminophen(ACT).The complete removal of 10 mg/L ACT is achieved over Gd-CMP/TG,and the corresponding rate constant of ACT degradation of nanohybrid is 40-fold higher than that of bare TiO_(2).In prepared ternary nanohybrid,metal-coordination sensitizer(Gd-CMP) acts as an electron donor,and at the same time,rGO serves as an electron acceptor,and the synergistic effect between them efficiently enhances charges separation and inhibits e/h pair recombination in the hybridized species.The radical scavenger tests indicate that the photo-induced O_(2)^(-·) radicals dominate ACT degradation.On the basis of the experimental results and calculated energy of electronic levels,a possible mechanism for the improved photocatalytic activity is discussed.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2017RIA2B4006388,NRF-2017R1D1A3B03035530)
文摘Upconversion phosphors are known as a material system that can convert near-infrared light into visible/ultraviolet emissions by sequentially absorbing multiple photons. The studies on upconversion materials often use two rare earth(RE) ions as a sensitizer-activator pair. We investigated the influences on luminescence intensity depending on Cr-doping content(x) of hexagonal NaLu_(0.98-x)Cr_xF4 Er_(0.02)(x = 0-0.9)upconversion material by substituting Lu^(3+) ions with Cr^(3+)in the absence of Gd^(3+). The change in upconversion luminescence intensity appears with saddle-like shape. We suggest that Cr^(3+) ions play the dual role as a constituent in host lattice and a sensitizer in the upconversion process. Optimal conditions for gaining the strongest upconversion emission correspond to x = 0.3-0.5, where there are effective energy transfers between Cr^(3+) and Er^(3+) ions and Cr-Er dimers. Apart from these values, the emission intensity decreases rapidly which can be ascribed to the absence of multiple-photon absorption for the case of low Cr^(3+) contents, and to the coupling between Cr^(3+) and/or Er^(3+) ions for the case of high Cr^(3+)contents. Magnetization and electron-spin-resonant measurements were performed to understand the correlation between the optical and magnetic properties.
文摘A polymer-bound photosensitizer was synthesized by the reaction of Merrifield resin with 9-anthracenemethanol in the presence of potassium hydride. The photoisomerization of trans-vitamin D3 to cis-vitamin D3 was carried out with this polymer-bound photosensitizer in ethanol and toluene solutions. The experiment results demonstrate that this solid photosensitizer is efficient for the photoismerization and easy for separation from the reaction mixtures.
基金financial support from the National Science Foundation of China(Nos. 61671435 and 81630053)Beijing Natural Science Foundation(No. 4161003)
文摘Although surgical resection and chemotherapy were widely applied in tumor therapy, the dysfunction of normal cells resulted in the side effects (such as anorexia, nausea). MW thermal therapy is a non-invasive anticancer strategy under the help of MW sensitizer, with the safety and higher efficacy. Zirconium metal-organic framework nanocubes (ZrMOF NCs) modified with polyethylene glycol, were prepared via one pot method and carbodiimide technique, resulting in their large specific surface area and porosity.Our results showed that non-ion-loaded ZrMOF NCs in 0.9% NaCl solution exhibited better heating effect,higher than that in pure water, due to the robust collision among the ions under MW irradiation. The in vivo experiments confirmed that ZrMOF-PEG NCs + MW group exhibited the higher temperature in the tumor region than that of only MW treatment, suggesting a better MW thermal therapeutic anticancer efficacy. This work provides a new preparation strategy of biosafety nanomaterial as MW sensitizer for enhancing MW thermal anticancer therapy.
基金This work supported by the National Natural Science Foundation of China （No.10647006）, the Promineat Youth Foundation （No.Q200704）, and the Scientific Developmental Foundation of Lanzhou University of Technology. Zi-jiang Liu would like to appreciate the Key Project of Chinese Minsitry of Education （No.209127）. Cai-rong Zhang would like to thank professor Wan-zhen Liang （USTC）, and the Gansu Supercomputer Center is also appreciated.
文摘The geometries, electronic structures, polarizabilities and hyperpolarizabilities, as well as the UV-Vis spectra of the two organic dye sensitizers containing bis-dimethylfluorenyl amino benzofuran were studied via density functional theory （DFT） and time-dependent DFT. The features of electronic absorption spectra were assigned on account of the agreement between the experiment and the calculations. The absorption bands in visible region are related to photoinduced electron transfer processes, and the dimethylfluorenyl amino benzo[b]furan groups are major chromophore that contributed to the sensitization of photo-to-current conversion. The role of vinylene group in geometry, electronic structure and spectra property is analyzed according to the comparative study of the dyes.
基金ACKNOWLEDGMENTS This work was supported by the NationM NaturM Science Foundation of China （No. 10647006）, the Prominent Youth Foundation （No.Q200704） and the Scientific Developmental Foundation of Lanzhou University of Technology. Cai-rong Zhang would like to thank Professor Wan-zhen Liang （USTC）, and the Gansu Supercomputer Center is also appreciated.
文摘The geometry, electronic structure, polarizability and hyperpolarizability of dye sensitizer 3,4-bis[1-（carboxymethyl）-3-indolyl]-1H-pyrrole-2,5-dione （BIMCOOH） were studied using density functional theory （DFT） with hybrid functional B3LYP, and the electronic absorption spectra were investigated using semi-empirical quantum chemical method ZINDO-1 and time-dependent DFT （TDDFT）. The results of natural bond orbital suggest that the natural charges of the dione, indole, and acetic groups are about 0.15e, -0.29e, and 0.44e, respectively. The calculated isotropic polarizability, polarizability anisotropy invariant and hyperpolarizability are 305.4, 188.3, and 1155.4 a.u., respectively. The electronic absorption spectral features in visible and near-UV region were assigned to the π→π^＊ transition due to the qualitative agreement between the experiment and the TDDFT calculations, and the transitions of the excited states 9-11 related to photoinduced intramolecular charge transfer processes. The analysis of electronic structure and UV-Vis absorption indicates that the indole groups primarily contributed sensitization of photo-to-currency conversion processes, and the interracial electron transfer between semiconductor TiO2 electrode and dye sensitizer BIMCOOH are electron injection processes from excited states of the dyes to the semiconductor conduction band.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.60425101）, the Program for the New Century Excellent Talents in University of Ministry of Education of China （No.NCET-06-0812）, and the Young Talent Project of University of Electronic Science and Technology of China （No.060206）.
文摘White organic light-emitting diodes were fabricated by using a novel phosphorescence bis（1,2-diphenyl-1H-benzoimidazole）iridium（acetylacetonate）[（pbi）2Ir（acac）] as sensitizer and a fluorescent dye of 4- （dicyanomethylene）-2-t-butyl-6-（1,1,7,7-tetramethyljulolidyl-9-enyl）-4H-pyran （DCJTB） codoped into a carbazole polymer of poly（N-vinylcarbazole） （PVK）. Through characterizing the UV-Vis absorption spectra, the photoluminescence spectra of （pbi）2Ir（acac） and DCJTB, and the electroluminescence spectral properties of the WOLEDs, the energy transfer mechanisms of the codoped polymer system were deduced. The results demonstrate that the luminescent spectra with different intensity of （pbi）2Ir（acac） and DCJTB were co-existent in the EL spectra of the blended system, which is ascribed to an incomplete energy transfer process in the EL process. The efficient Forster and Dexter energy transfer between the host and the vips enabled a strong yellow emission from （pbi）2Ir（acac） and DCJTB, where （pbi）2Ir（acac） plays an important role as a phosphorescent sensitizer for DCJTB. With the blue emitting-layer of N,N＇-diphenyl-N,N＇-bis（1- naphthyl）（1,1＇-biphenyl）-4,4＇-diamine, the codoped system device achieved white emission. The codoped system showed that its Commissions Internationale de 1＇Eclairage coordinates were more independent of the variation of bias voltage than those of phosphorescent doped PVK systems.
文摘A new method for the determination of utratrace silver(I) by near field thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromocresol green oxidized by sodium persulphate in the presence of a, a-bipy as activator and Triton X-100 as sensitizer. The linear range of this method is 0~1.6 ng穖L-1 of silver. The detection limit is 2?0-2 ng穖L-1. The method has been applied to the determination of silver in lead power and photographic paper with satisfactory results.
文摘Four sensitizers of high purity were synthesized with high yield. Their structures were verified by IR spectra and elementary analysis. The tricomponent eutectoid point determined by thermal analysis and the optical density determined by static and dynamic color development tests show that these sensitizers can lower the temperature and increase the rate of color development as well as enhance the optical .tensity when used in thermal sensitive materials.
文摘The research on sensitizer for dye sensitized solar cells based on (metallo)porphyrin/phthalocyanine materials were reviewed, and experimental design and assembly method were advised. Latest progress and research status of sensitizer dyes based on metalloporphyrins applied in dye sensitized solar cells was summarized. The preparation and construction of sensitizer electrodes and dye sensitized solar cells based on metal organic frameworks (MOFs) of (metallo)porphyrin/phthalocyanine were projected.
文摘Dye-sensitized solar cells (DSSC) were fabricated with mango leaf dye extracts as natural dye sensitizers at pH value of 5.20 and temperature of 18.1°C. Methanol was used as dye-extracting solvent. DSSCs from dye extract of M. indica L. with KMnO4 electrolyte had the highest photocurrent density of 1.3 mA/cm2 and fill factor FF of 0.46 for the sun at its peak. Potassium permanganate (KMnO4) had a photocurrent density of 1.3 mA/cm2 and FF of 0.8 at sundown. Potassium Iodide (KI), Potassium Bromide (KBr) and Mercury Chloride (HgCl2) electrolytes had 0.2 mA/cm2, 0.08 mA/cm2 and 0.02 mA/cm2 photocurrent densities respectively. The fill factors of 0.09, 0.03 and 0.003 respectively for sun overhead while 0.08 mA/cm2, 0.01 mA/cm2 and 0.01 mA/cm2 were the values of photocurrent densities respectively at sundown. The fill factors were 0.02, 0.0006 and 0.003 respectively at sundown. The maximum power Pmax of the DSSCs were 0.5 mW/cm2, 0.10 mW/cm2, 0.01 mW/cm2 and 0.012 mW/cm2 respectively at 1300 h at 1630 h 0.9 mW/cm2, 0.14 mW/cm2, 0.005 mW/cm2 and 0.0015 mW/cm2 respectively.
文摘Carbon quantum dots(CQDs)are emerging as the new-generation light absorber for solar energy conversion.However,the low photosensitization efficiency of CQDs is one of the current bottlenecks impeding their large-scale practical applications in photocatalysis.Therefore,developing a facile approach for the engineering and functionalization of CQDs-based composites to improve the photosensitization efficiency of CQDs is highly desirable.On account of the abundant functional groups,especially oxygen-containing functional groups such as carbonyl,carboxyl,and hydroxyl present on their surface,CQDs can be readily combined with various organic molecules or polymers as a surface passivation component to reduce the nonradioactive surface recombination of photo-generated charge carriers,thus enabling the CQDs to exhibit strong photoluminescence in the visible and near-infrared spectral regions.Consequently,polymer passivation has been demonstrated as an ideal strategy to make it accessible for improving the sensitization efficiency of CQDs in photocatalytic applications.Branched polyethylenimine(BPEI)is one of polymers that contains a high density of amine groups and exhibits high electron mobility,which can be used as an electron injection material at the interface of nanomaterials.Besides,the BPEI polymer with amino groups exhibiting positive charge has been utilized for designing heterogeneous catalysts by an electrostatic self-assembly strategy.Therefore,BPEI is expected to modify the surface of inorganic oxides semiconductor to enhance the photosensitization efficiency of CQDs under visible light.However,to date,the study in this regard has been still unavailable In this work,we developed a facile approach to engineer well-distributed CQDs via electrostatic interaction on BPEI passivated TiO2 composites(BTC)as photocatalysts.The BTC composites with an optimal loading of 5%(w,mass fraction)CQDs outperformed the TiO2/CQDs(TC)composite and referential BPEI/SiO2/CQDs(BSC)composites for the photoreduction of 4-nitroaniline under visible light irradiation.The structure of the fabricated BTC composites was systematically investigated by the combined use of structural and spectral characterizations,demonstrating that the photosensitizer CQDs contacted well with the BPEI modified TiO2 nanoparticles.The comparison characterizations revealed that BPEI facilitated the dissociation and transfer of excitons as an electron transfer channel.The as-prepared BTC composites benefited from the favorable interfacial contact and effective transfer of photo-generated charge carriers,and thus manifested superior photocatalytic activity to the TC composite.It is expected that this strategy would be extended to other wide band gap semiconductor photocatalyst systems and open up new possibilities in designing efficient CQDs-based semiconductor artificial light harvesting systems by interfacial optimization.
基金Supported by the National Natural Science Foundation of China( No.2 0 175 0 11) and the Natural Science Foundation ofFujian Province( No.C0 110 0 2 8)
文摘A new highly sensitive solid substrate room temperature phosphorimetry for the determination of trace titanium is proposed based on the sensitization of Triton X-100 to the SS-RTP intensity of 4,5-dibromophenylfluorone-titanium complex adsorbed on the filter paper substrate modified by gelatin. When Triton X-100 was added into the luminescence system, the RTP intensity was raised 3 times stronger than that of the system without Triton X-100. The linear dynamic range of the new method is 0 64~3 2 fg/spot(0 4 μL) with a detection limit of 12 8 ag/spot, and the regression equation of the working curve is Δ I p =482 0+119 5 m Ti(Ⅳ) (fg/spot), the correlation coefficient r =0 9992, n =6. The phosphorescence lifetime( τ =0 85 ms) was also determined. The recoveries(and RSD) for the determinations of titanium in human hair and tea samples were 101 0%(3 0%) and 99 97%(4 2%), respectively.
基金the National Natural Science Foundation of China(No.22105215)Ningbo Yongjiang Talent Introduction Programme(No.2022A-198-G),and Ningbo Natural Science Foundation(No.2024J006)+3 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LQ23H180001)the support from the National Natural Science Foundation of China(No.22107104)Ningbo Natural Science Foundation(No.2023J066)the National Natural Science Foundation of China(No.22175035).
文摘Aromatic ketones,such as 9-fluorenone(9-FO),are known for their high intersystem crossing quantum yields(Φ_(ISC)≈1),rendering them highly valuable for photochemical reactions and dye-sensitized solar cells.However,their use as photosensitizers in biological contexts has been hindered by their low extinction coefficients,high excitation energies,and weak fluorescence.To address these limitations,we conjugated 9-FO with a fused-ring electron donor,resulting in an acceptor-donor-acceptor derivative IDT-9F.This strategy has successfully redshifted the absorption peak of 9-FO(380 nm)into the visible light range(498 nm)and significantly enhanced its light absorption capability(~310-fold)and fluorescence quantum yield(~100-fold).Furthermore,IDT-9F was encapsulated within pH-responsive nanoparticles using an acid-induced charge-reversal polymer as the amphiphilic matrix,and enabled fluorescence imaging-guided photodynamic inactivation of Gram-positive bacteria in acidic environment with a remarkable bacterial inhibition rate exceeding 99.9%.
基金This work is supported by the National Institute of Health research projects(DK085495,DK068036).
文摘Insulin resistance is a major risk factor for type 2 diabetes.AMP-activated protein kinase(AMPK)is a drug target in the improvement of insulin sensitivity.Several insulin-sensitizing medicines are able to activate AMPK through inhibition of mitochondrial functions.These drugs,such as metformin and STZ,inhibit ATP synthesis in mitochondria to raise AMP/ATP ratio in the.process of A MPK activation.However,chemicals that activate AMPK directly or by activating its upstream kinases have not been approved for treatment of type 2 diabetes in humans.In an early study,we reported that berberine inhibited oxygen consumption in mitochondria,and increased AMP/ATP ratio in cells.The observation suggests an indirect mechanism for AMPK activation by berberine.Berberine stimulates glycolysis for ATP production that offsets the cell toxicity after mitochondria inhibition.The study suggests that mitochondrial inhibition is an approach for AMPK activation.In this review article,literature is critically reviewed to interpret the role of mitochondria function in the mechanism of insulin resistance,which supports that mitochondria inhibitors represent a new class of AMPK activator.The inhibitors are promising candidates for insulin sensitizers.This review provides a guideline in search for small molecule AMPK activators in the drug discovery for type 2 diabetes.
基金the National Key R&D program of China(No.2017YFA0207303)the National Natural Science Foundation of China(Nos.21725502 and 21701027)Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.17JC1400100).
文摘Trivalent lanthanide(Ln2+)doped luminescent nanocrystals are promising for applications ranging from biosensor,lasing,super-resolution nanoscopy,information security and so on.Although the utility prospect is of great attractions,the light absorption of these lanthanide doped nanocrystals is inherently weak due to the electric dipole-forbidden 4f→4f transitions.Even worse,the quantum yields of upconverison nanocrystals are very low,which will unavoidably hinder their further applications.In a typical lanthanide luminescent nanosystem,both sensitizers as light absorption centers and activators as light emitting centers are necessary and important for desired luminescence properties.Among various sensitization systems,only Yb3+and Nd+are considered as the most efficient sensitizers.Thus,the corresponding excitation wavelengths are strictly limited around 980 and 808 nm.To enrich excitation wavelengths and boost luminescence intensity,exploring more sensitization units that possess larger absorption cross section,higher efficiency of energy transfer process and independent excitation is imperative and beneficial for the demands of different applications,such as broadened absorption in near infrared(NIR)region for higher conversion efficiency of solar cells,prolonged excitation wavelength to second near infrared windows region(NIR Ⅱ,1,000-1,700 nm)for in vivo fluorescence imaging with deeper tissue depth and higher spatial resolution,more orthogonal excitations and emissions to improve optical multiplexing,and so on.Therefore,in the review,we primarily conclude several major energy transfer mechanisms from sensitizers to activators.Then we present three kinds of sensitizers,including lanthanide ions,organic dyes and quantum dots(QDs),and introduce the newly designed sensitization system that allows us to exploit superior excitation wavelength and amplity luminescence intensity.Finally,several future challenges and opportunities for the sensitizing strategies are discussed in hope of directing and broadening the applications of lanthanide nanosystem.
基金supported by the National Natural Science Foundation of China(81871481 and 81571802)the Fujian Provincial Youth Top-notch Talent Support program(China)National Key R&D Program of China(2020YFA0210800)
文摘Many sensitizers have not only photodynamic effects,but also sonodynamic effects.Therefore,the combination of sonodynamic therapy(SDT)and photodynamic therapy(PDT)using sensitizers for sonophotodynamic therapy(SPDT)provides alternative opportunities for clinical cancer therapy.Although significant advances have been made in synthesizing new sensitizers for SPDT,few of them are successfully applied in clinical settings.The anti-tumor effects of the sensitizers are restricted by the lack of tumor-targeting specificity,incapability in deep intratumoral delivery,and the deteriorating tumor microenvironment.The application of nanotechnology-based drug delivery systems(NDDSs)can solve the above shortcomings,thereby improving the SPDT efficacy.This review summarizes various sensitizers as sono/photosensitizers that can be further used in SPDT,and describes different strategies for enhancing tumor treatment by NDDSs,such as overcoming biological barriers,improving tumor-targeted delivery and intratumoral delivery,providing stimuli-responsive controlled-release characteristics,stimulating anti-tumor immunity,increasing oxygen supply,employing different therapeutic modalities,and combining diagnosis and treatment.The challenges and prospects for further development of intelligent sensitizers and translational NDDSs for SPDT are also discussed.
基金supported by the National Research Foundation of South Africabased on the research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation of South Africa(Grant No.98337)+2 种基金the University of Johannesburgthe National Laser Centrethe National Research Foundation-South African Research Chairs Initiative(NRF-SARChI)for their financial grant support。
文摘Cancer remains one of the diseases with the highest incidence and mortality globally.Conventional treatment modalities have demonstrated threatening drawbacks including invasiveness,noncontrollability,and development of resistance for some,including chemotherapy,radiation,and surgery.Sono-photodynamic combinatorial therapy(SPDT)has been developed as an alternative treatment modality which offers a non-invasive and controllable therapeutic approach.SPDT combines the mechanism of action of sonodynamic therapy(SDT),which uses ultrasound,and photodynamic therapy(PDT),which uses light,to activate a sensitizer and initiate cancer eradication.The use of phthalocyanines(Pcs)as sensitizers for SPDT is gaining interest owing to their ability to induce intracellular oxidative stress and initiate toxicity under SDT and PDT.This review discusses some of the structural prerequisites of Pcs which may influence their overall SPDT activities in cancer therapy.
基金supported by the National Natural Science Foundation of China (20703015,20973076,and 21003057)Program for New Century Excellent Talents in Heilongjiang Provincial University of China (1154-NCET-010)
文摘A variety of heteroleptic ruthenium sensitizers have been engineered and synthesized because of their higher light-harvesting efficiency and lower charge-recombination possibility than the well known homoleptic N3 dye. As such, a great deal of atten- tion has been focused on sensitizers with the general formula Ru（ancillary-ligand）（anchoring-ligand）（NCS）2, among which important examples are Ru（4,4＇-bis（5-hexylthiophen-2-yl）-2,2＇-bipyridine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （C101） and Ru（N-（4-butoxyphenyl）-N-2-pyridinyl-2-pyridinamine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （J13）. In order to simulate experimental conditions with different pH values, the photosensitizing processes of these sensitizers pos- sessing different degrees of deprotonation （2I-I, lit to OH） have been explored theoretically in this work. Their ground/excited state geometries, electronic structures and spectroscopic properties are first calculated using density functional theory （DFT） and time-dependent DFT （TDDFT）. The absorption and emission spectra of all the complexes in acetonitrile solution are also predicted at the TDDFT （B3LYP） level. The calculated results show that the ancillary ligand contributes to the molecular or- bital （MO） energy levels and absorption transitions. It is intriguing to observe that the introduction of a thiophene group into the ancillary ligand leads directly to the increased energy of the absorption transitions in the 380-450 nm region. The calcula- tions reveal that although deprotonation destabilizes the overall frontier MOs of the chromophores, it tends to exert a greater influence on the unoccupied orbitals than on the occupied orbitals. Consequently, an obvious blue shift was observed for the absorptions and emissions in going from 21-1, 1H to OH. Finally, the optimal degree of deprotonation for C101 and J13 has al- so been evaluated, which is expected to lead to further improvements in the performance of dye-sensitized solar cells （DSSCs） coated with such sensitizers.
