Influence of zinc phthalocyanines on photoelectrical properties of hydrogenated amorphous silicon

Composites consisting of hydrogenated amorphous silicon （a-Si： H, inorganic） and zinc phthalocyanine （ZnPc, organic） were prepared by vacuum evaporation of ZnPc and sequential deposition amorphous silicon via plasma enhanced chemical vapor deposition （PECVD）. The optical and electrical properties of the composite film have been investigated. The results demonstrate that ZnPc can endure the temperature and bombardment of the PECVD plasma and photoconductivity of the composite film was improved by 89.9% compared to pure a-Si： H film. Electron mobility-lifetime products/lr of the composite film were increased by nearly one order of magnitude from 6.96 × 10^-7 to 5.08 × 10^-6 cm2/V. Combined with photoconductivity spectra of the composites and pure a-Si： H, we tentatively elucidate the improvement in photoconductivity of the composite film.

Influence of dye molecular structure on electron transfer in 2,9,16,23-tetracarboxy zinc phthalocyanine sensitized solar cell

2, 9, 16, 23-tetracarboxy zinc phthalocyanine （ZnTCPc） is synthesized and characterized by physicochemical and theoretical methods and it is used as a photosensitizer in dye-sensitized solar cells （DSSC）. The excited lifetime, band gap and frontier orbital distribution of ZnTCPc are investigated by fluorescence spectra, cyclic voltammetry and quantum calculation. The results show that the excited lifetime and band gap are 0. 1 ns and 1.81 eV, respectively. Moreover, it is found that the highest occupied molecular orbital （HOMO） location is not shared by both the zinc metal and the isoindoline ligands, and the lowest unoccupied molecular orbital（LUMO） location does not strengthen the interaction coupling between ZnTCPc and TiO：. As a result, the ZnTCPc-DSSC gains a short-circuit current density of 0. 147 mA/cm2, an open-circuit photovoltage of 277 mV, a fill factor of 0. 51 and an overall conversion efficiency of 0. 021%.

Zinc phthalocyanine as an efficient catalyst for halogen-free synthesis of formamides from amines via carbon dioxide hydrosilylation under mild conditions

The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We deduced that formation of an active zinc‐hydrogen(Zn‐H)species promoted hydride transfer from the hydrosilane to CO2.The cooperative activation of the Lewis acidic ZnPc by strongly polar DMF,led to formation of activated amines and hydrosilanes,which promoted the chemical reduction of CO2.Consequently,the binary ZnPc/DMF catalytic system showed excellent yields and superior chemoselectivity,representing a simple and sustainable pathway for the reductive transformation of CO2into valuable chemicals as an alternative to conventional halogen‐containing process.

Spectroscopic Properties of a Novel Zinc Phthalocyanine with four 17-Membered Crown Ether Voids

A zinc phthalocyanine containing (17-crown-5) ether subunits has been synthesized UV-visible absorption and fluorescence emission spectra and associated photophysical parameters have been determined. In addition to the fluorescence at 710 nm from S-1, a strong upper excited state emission around 424 nn has been detected. X-ray structural analysis showed that the crown ether unit is conformationally deformed and oblate like that accounted for the unusual spectroscopic properties.

PHOTOINDUCED ELECTRON TRANSFER I.INTER-AND INTRAMOLECULAR QUENCHING OF ZINC PHTHALOCYANINE FLUORESCENCE BY ANTHRAQUINONE

Inter-and intramolecular quenching of zinc phthalocyanine fluorescence by anthraquinone has been studied.The diminutions of fluorescence quantum yield and life-time are due primarily to electron transfer.Apparent electron transfer rate constants were calculated depending on the chain length and solvent polarity.

Increased performance of an organic light-emitting diode by employing a zinc phthalocyanine based composite hole transport layer

We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine （ZnPc）-based composite hole transport layer （c-HTL）. The optimum ris-（8-hydroxyquinoline）aluminum （Alq3）-based organic light-emitting diode with a c-HTL exhibits a lower turn-on voltage of 2.8 V, a higher maximum current efficiency of 3.40 cd/A and a higher maximum power efficiency of 1.91 lm/W, which are superior to those of the conventional device （turn-on voltage of 3.8 V, maximum current efficiency of 2.60 cd/A, and maximum power efficiency of 1.21 lm/W）. We systematically studied the effects of different kinds of N’-diphenyl-N,N’-bis（1-naphthyl）（1,1’-biphenyl）-4,4’diamine （NPB）：ZnPc c-HTL. Meanwhile, we also investigate their mechanisms different from that in the case of using ZnPc as buffer layer. The specific analysis is based on the absorption spectra of the hole transporting material and current density–voltage characteristics of the corresponding hole-only devices.

Targeting Hypoxic Tumors with Hybrid Nanobullets for Oxygen-Independent Synergistic Photothermal and Thermodynamic Therapy

Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment.Herein,we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the“precise strike”of hypoxic tumors through the dual-targeting effects from surface-modified hyaluronic acid(HA)and hypoxia-dependent factor carbonic anhydrase IX(CA IX)-inhibitor acetazolamide(AZ).The core of nanobullets is the special zinc(II)phthalocyanine aggregates(ZPA)which could heat the tumor tissues upon 808-nm laser irradiation for photothermal therapy(PTT),along with the alkyl chain-functionalized thermally decomposable radical initiator ACVA-HDA on the side chain of HA for providing oxygen-independent alkyl radicals for ablating hypoxic cancer cells by thermodynamic therapy(TDT).The results provide important evidence that the combination of reverse hypoxia hallmarks CA IX as targets for inhibition by AZ and synergistic PTT/TDT possess incomparable therapeutic advantages over traditional(reactive oxygen species(ROS)-mediated)cancer treatment for suppressing the growth of both hypoxic tumors and their metastasis.

One-pot preparation of nanodispersion with readily available components for localized tumor photothermal and photodynamic therapy

Photothermal(PTT) and photodynamic(PDT) combined therapy has been hindered to clinical translation, due to the lack of available biomaterials, difficult designs of functions,and complex chemical synthetic or preparation procedures. To actualize a high-efficiency combination therapy for cancer via a feasible approach, three readily available materials are simply associated together in one-pot, namely the single-walled carbon nanohorns(SWCNH), zinc phthalocyanine(ZnPc), and surfactant TPGS. The established nanodispersion is recorded as PCT. The association of SWCNH/ZnPc/TPGS was confirmed by energy dispersive spectrum, Raman spectrum and thermogravimetric analysis. Under lighting, PCT induced a temperature rising up to about 60 ℃ due to the presence of SWCNH, production a 7-folds of singlet oxygen level elevation because of ZnPc, which destroyed almost all4T1 tumor cells in vitro. The photothermal effect of PCT depended on both laser intensity and nanodispersion concentration in a linear and nonlinear manner, respectively. After a single peritumoral injection in mice and laser treatment, PCT exhibited the highest tumor temperature rise(to 65 ℃) among all test groups, completely destroyed primary tumor without obvious toxicity, and inhibited distant site tumor. Generally, this study demonstrated the high potential of PCT nanodispersion in tumor combined therapy.

Zinc Phthalocyanine Thin Film-Based Optical Waveguide H_(2)S Gas Sensor

The detection of hydrogen sulfide(H_(2)S)is essential because of its toxicity and abundance in the environment.Hence,there is an urgent requisite to develop a highly sensitive and economical H_(2)S detection system.Herein,a zinc phthalocyanine(ZnPc)thin film-based K+-exchanged optical waveguide(OWG)gas sensor was developed for H_(2)S detection by using spin coating.The sensor showed excellent H_(2)S sensing performance at room temperature with a wide linear range(0.1 ppm 500 ppm),reproducibility,stability,and a low detection limit of 0.1ppm.The developed sensor showed a significant prospect in the development of cost-effective and highly sensitive H_(2)S gas sensors.

Synthesis and photoactivity of pH-responsive amphiphilic block polymer photosensitizer bonded zinc phthalocyanine

A zinc tetraaminophthalocyanine derivative, zinc tetra(methacryloyl moiety)aminophthalocyanine (MeZnAPc) (with a double bond) was synthesized by the reaction between zinc tetraaminophthalocyanine (ZnTAPc) and methacryloyl chloride. Atom transfer radical polymerization (ATRP) was employed as the polymerization technique to obtain a novel pH-responsive poly- meric photosensitizer (PEGIlo-b-P(DPA,rco-MeZnAPcm)) by copolymerizing of methoxypolyethylene glycols (MPEG) (as reducing agent), 2-(isopropylamino)ethyl methacrylate (DPA) and MeZnAPc. This photosensitizer was characterized by UV-vis spectroscopy, FTIR, ~H NMR, etc. The results indicated that the photosensitizer presented the well pH-responsive be- havior around the pH range 6.0-6.5 and the high photoactivity to 1,3-diphenylisobenzofuran (DPBF). The result of photoca- talysis oxidation of L-tryptophan (L-Try) suggested that zinc phthalocyanine could present high photoactivity due to its disper- sivity at pH 5.5 without formation of micelles, and its photoactivity decreased dramatically at pH 7.4 due to wrapping ZnTAPc into the micelles. Therefore, the novel pH-responsive polymeric photosensitizer has better application prospects in the field of photodynamic therapy.

Singlet Oxygen Generation and Photoinduced Charge Separation of Tetra Polyethyleneglycol Functionalized Zinc Phthalocyanine-Fullerene Dyad

Utilization of polyethyleneglycol （PEG） functionalized zinc phthalocyanine, （PEG）4ZnPc in （i） singlet oxygen generation, and （ii） in building energy harvesting donor-acceptor systems using fullerene, C60 as an acceptor via the well-known metal-ligand axial coordination approach is reported. The （PEG）4ZnPe was found to be capable of producing singlet oxygen with a quantum yield, ooa of 0.77 in toluene, a value higher than that obtained for pristine （t-bu）4ZnPc （φ△=0.54） carrying no PEG groups, revealing its usefulness in photodynamic therapy applications. Spectroscopic studies revealed efficient binding of phenylimidazole functionalized fullerene, C60 Im with l ： 1 stoichiometry to （PEG）4ZnPc. Binding constant K for the formation of （PEG）4ZnPc：ImC60 dyad was found to be 6 × 103 M 1 revealing moderate stability. Geometric and electronic studies of the dyad was arrived by B3LYP/3-21G（＊） method. The HOMO level was found to be on zinc phthalocyanine entity while the LUMO level was found to be on the C60 entity suggesting formation of （PEG）4ZnPc＊＋：ImC60＊ charge separated state during the process of electron transfer reaction. Redox studies on the （PEG）4ZnPc：ImC60 dyad enabled accurate determination of the oxidation and reduction potentials of the donor-acceptor system, and to evaluate free-energy changes associated for the charge separation process. Kinetics of photoinduced charge separation and recombination in the （PEG）4ZnPc：ImC60 dyad was investigated using femtosecond transient absorption studies. Relatively long-lived charge separated states were confirmed for the dyad suggesting their potential usefulness in energy harvesting applications.

Synthesis of organic semiconductor hexadecachloro zinc phthalocyanine and its gas sensitivity

Due to the difficulty in synthesizing perhalogenated metallophthalocyanine, the method of ammonium molybdate solid phase catalysis was introduced, and by using tetrachlorophthalic anhydride and urea as the raw materials, hexadecachloro zinc phthalocyanine （ZnPcCl16） was synthesized. Components of the composite were analyzed by energy spectrum, and its functional group structures and absorption peaks were characterized by IR and UV-vis spectroscopy. The thin films of gas sensors were prepared in a vacuum evaporation system and evaporated onto SiO2 substrates, where sensing electrodes were made by MEMS micromachining. The optimal conditions for the films are： substrate temperature of 150 ℃ evaporation current of 95 A and film thickness of 50 nm. The result showed that the sensors were ideally sensitive to Cl2 gas and could detect the minimum concentration of 0.3 ppm.

Conjugation of Disassembled Zincphthalocyanine-based Nanocomposites and the Synergistic Effect on Visible-light Photosensitive Activity

In this research,a conjugated Pc-MIL-88B(Fe)nanoplatform was constructed via a condensation process between modified zinc phthalocyanine and MIL-88B(Fe)for the removal of organic pollutants.The as-prepared material was fully characterized by TEM,XPS,ICP,FTIR,UV-Vis,N_(2) adsorption-desorption isotherm,etc.The results indicate that Pc-MIL-88B(Fe)preserved the topological structure of MIL-88B(Fe),and the micropores of framework could effectively prevent the aggregation of Pc in water.Meanwhile,the conjugated Pc-MIL-88B(Fe)basically maintains the singlet oxygen quantum yield of Pc,and behaves a much higher photocurrent intensity compared to NH_(2)-MIL-88 B(Fe).Additionally,the photosensitive activity and reusability of Pc-MIL-88B(Fe)were evaluated by the degradation of methylene blue in aqueous solution under visible light irradiation,and the degradation mechanism was also investigated in detail.

Mode-locked ytterbium-doped fiber laser with zinc phthalocyanine thin film saturable absorber

A stable mode-locked laser was demonstrated using a newly developed zinc phthalocyanine(ZnPc)thin film as passive saturable absorber(SA)in ytterbium-doped fiber laser(YDFL).The ZnPc thin film was obtained using a casting method and then inserted between the two fiber ferrules of a YDFL ring cavity to generate mode-locked pulses.The resulting pulsed laser operated at a wavelength of 1034.5 nm having a repetition rate of 3.3 MHz.At pump power of 277 mW,the maximum output power and pulse energy are achieved at 4.92 mW and 1.36 nJ,respectively.ZnPc has a high chemical and photochemical stability,and its significance for use as a potential SA in a mode-locked laser is reported in this work.

Quenching of zinc phthalocyanine excited states by viologen surfactant assemblies——The influence of microenvironment

A series of functional surfactants of N-alkyl-N'-butyl viologens has been synthesized. The quenching of excited singlet and triplet states of zinc phthalocyanine was studied in DMSO and in mixed micelles containing the functional surfactant as one and cationic cetyl trimethylam- monium bromide(CTAB),anionic sodium dodecylsulfate(SDS)and neutral TX-100 surfactant as the other component.Fluorescence quenching and laser photolysis studies indicate that the functional surfactants are solubilized at different sites in micelles,the process depends on chain length and exerts great influence on the quenching of zinc phthalocyanine excited states.

Experimental studies of the effects of ZnPcS_2P_2-based-photodynamic therapy on bone marrow purging

Background An effective purging technique plays an important role in autologous hematopoietic stem cells transplantation Photodynamic therapy (PDT) provides a novel approach for this purpose This study dealt with the purging effects of disulfodiphthalimidomethyl phthalolcyanine zinc (ZnPcS2P2)based photodynamic therapy (ZnPcPDT) Methods Fluorescence intensity of cell extracts was measured using a fluoresence spectrophotometry The proliferative potency of K562 cells and HL60 cells was detected using MTT colorimetric assay, Typan blue dye exclusion method, colony formation test The proliferative potency of normal hematopoietic cells was evaluated using mixture colonyforming unit (CFUMix), granulocytemacrophage colonyforming unit (CFUGM), and erythrocyte colonyforming unit (CFUE) assays K562 cells were mixed with normal mononuclear cells (MNCs) at ratios of 1∶100 and 1∶1000 for creating the model of simulated remission bone marrow Colony formation test and nestedRTPCR were carried out to detect the residual K562 cells in cell mixture Results After a 5hour incubation with ZnPcS2P2, the content of ZnPcS2P2 in normal MNCs was the lowest value At the same time, the content in K562 cells and HL60 cells was very high Therefore, the time point was selected as the optimal one for irradiating the cell suspensions ZnPcPDT could significantly kill proliferative K562 cells and HL60 cells in a dosedependent manner At the concentration of 10 μg/ml, the inhibitory rate of ZnPcPDT on the colony formation was 100% for K562 cells, 897% for HL60 cells 025 μg/ml ZnPcPDT could completely photoinactivate residual K562 cells in the simulated remission bone marrow Under an identical condition, the inhibitory rates of CFUMix, CFUGM, CFUE were 180%, 186%, and 178% respectively Conclusion ZnPcPDT appears to be a promising approach for bone marrow purging

A strategy for enhanced tumor targeting of photodynamic therapy based on Escherichia coli-driven drug delivery system

Escherichia coli(E. coli) DH5α has been recognized as a non-pathogenic bacterial strain with tumor colonization ability. However, whether such a bacteria-driven drug-delivery system can improve the targeting of tumor therapy or not remains essentially untouched. Herein, a series of zinc phthalocyanine(ZnPc) photosensitizers with different numbers of charges were prepared and their electrostatic adhesion properties on E. coli were investigated via measuring their fluorescence intensities by flow cytometer. Among these ZnPc photosensitizers investigated, the ZnPc conjugate with four positive charges(named ZnPc-IR710) exhibited the highest loading capacity and the best fluorescence imaging performance of E. coli. With the help of E. coli, E. coli@ZnPcIR710 presented a significantly enhanced cytotoxicity on human breast cancer MCF-7 cells compared with ZnPc-IR710(survival rate of tumor cells was 39% vs. 57% at a concentration of 50 nmol L-1). Moreover, in vivo study showed that E. coli@ZnPc-IR710 remarkably inhibited the tumor growth and resulted in a complete tumor growth suppress in subcutaneous mouse 4T1 breast tumor model. These results demonstrated the great promise of bacterial-guided photodynamic therapy(PDT) in the treatment of solid tumors, and provide a unique strategy to enhance the antitumor efficacy of PDT by utilizing bacterial vectors in tumors.

Formation of heterocaryotic and homonuclear bridged–dimeric complexes on surface

The formation of coordinated dimeric complexes bridged by axial ligands on surface is observed with the help of a 1,3,5-tris（10-carboxydecyloxy）benzene（TCDB） template through scanning tunneling microscopy（STM）. STM images of molecular adlayers of zinc tetraphenylporphyrin（Zn TPP）, zinc phthalocyanine（Zn Pc）, and their mixture are reported. Zn TPP and Zn Pc can spontaneously form highly an ordered structure with a 1：1 molar ratio, which is different from that of individual Zn Pc. The coordinated bimolecular complexes bridged with axial ligands, simply as Zn Pc–DPP–Zn TPP and Zn Pc–DPE–Zn Pc, are presented and the corresponding surface structures are compared. Zn Pc and Zn TPP can be connected by an axial ligand DPP and formed assembled structures out of surface. Two types of arrays with entirely new structure are obtained for the Zn Pc–DPE–Zn Pc complex. These bridged hybrid complexes provide an example of design of self-organized crystals on the basis of coordination through non-covalent interactions.