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Herein we report that readily available 4‐alkenylisocoumarins can be regarded as potent dienolate equivalents. For example, lactol silyl ethers derived from 4‐alkenylisocoumarins were selectively converted to the corresponding benzo‐homophthalates through a fluoride‐induced ring opening step that was followed by a ring closure through a vinylogous intramolecular aldol condensation. Likewise, nucleophilic activation of 4‐alkenylisocoumarins directly yields diversely poly‐substituted naphthalenes and anthracenes without formation of any regioisomer. Photophysical evaluation of a set of thus obtained 1,3‐di‐ and 1,3,4‐trisubstituted anthracenes reveals their distinct intramolecular charge transfer (ICT) character during light absorption in polar solutions and excimer emission from the solid state when a face‐to‐face π‐stacked molecular assembly is present in the crystal packing. [ABSTRACT FROM AUTHOR]

Radical thermally initiated homopolymerization of methacrylic monomers based on aurone has been studied. Photochemical properties of these methacrylic monomers by UV-visible spectroscopy were investigated. It is shown that the new compounds are capable to radical homopolymerization and photoinduced cis-trans isomerization. It was found that increasing the electron donation of the substituent accelerates the process of radical homopolymerization of monomers. It was found that increasing the electron acceptance of the substituent accelerates the process of cis-trans isomerization. The rate constants and half-transformation times of cis-trans photoisomerization were determined by the tangent of the slope of the dependence Ln(Dfss-D0)/(Dfss-Dt) on the irradiation time of the solutions. [ABSTRACT FROM AUTHOR]

1,3‐Disubstituted N‐aryl‐2H‐isoindoles have been synthesized by a cascade reaction of divinyl ethers, which are derived from easily available 4‐bromoisocoumarins, with substituted anilines in HFIP. This cascade reaction consists of a ring‐opening step through addition‐elimination mechanism and the following 5‐exo‐tet type ring‐closing step via the intramolecular nucleophilic substitution reaction. Thus obtained 2H‐isoindoles have been derivatized to high‐order nitrogen‐containing polycycles including less accessible benzo[a]ullazines. [ABSTRACT FROM AUTHOR]

Photophysical properties of a series of bis(arylydene)cycloalkanone dyes with various donor substituents are studied using quantum chemistry. Their capacity for luminescence and nonradiative relaxation through trans–cis isomerization is related to their structure, in particular, to the donor capacity of the substituents and the degree of conjugation due to the central cycloalkanone moiety. It is shown that cyclohexanone central moiety introduces distortions and disrupts the conjugation, thus leading to a nonmonotonic change in their properties. The increasing donor capacity of the substituents causes increase in the HOMO energy (rise in the oxidation potential) and decrease in the HOMO–LUMO gap, which results in the red shift of the absorption spectra. The ability of the excited dye to relax through fluorescence or through trans–cis isomerization is governed by the height of the barrier between the Franck–Condon and S1–S0 conical intersection regions on the potential energy surface of the lowest π-π* excited state. This barrier also correlates with the donor capacity of the substituents and the degree of conjugation between the central and donor moieties. The calculated fluorescence and trans–cis isomerization rates are in good agreement with the observed fluorescence quantum yields. [ABSTRACT FROM AUTHOR]

As a new zero‐dimensional carbon‐based material, carbon dots (CDs) have attracted extensive attention owing to their advantages such as easy preparation and surface modification, good biocompatibility and water solubility, and tunable photochemical properties. CDs have become one of the most promising nanomaterials in the field of fluorescent sensing, bioimaging, and cancer therapy. How to precisely regulate the photochemical properties, especially the absorption, fluorescence, phosphorescence, reactive oxygen species generation, and photothermal conversion of the CDs, is the key to developing highly efficient phototheranostics for cancer treatment. Although many studies on cancer therapy using CDs have been published, no review has focused on the regulation of photochemical properties of CDs for phototheranostic applications. In this review, we summarized the strategies such as the selection of suitable carbon source, heteroatomic doping, optimum reaction conditions, surface modification, and assembly strategy to efficiently regulate the photochemical properties of the CDs to meet the requirements of different practical applications. This review might provide some valuable insight and new ideas for the development of CDs with excellent phototheranostic performance. This article is categorized under:Therapeutic Approaches and Drug Discovery > Emerging TechnologiesNanotechnology Approaches to Biology > Nanoscale Systems in BiologyDiagnostic Tools > In Vivo Nanodiagnostics and Imaging [ABSTRACT FROM AUTHOR]

Triangular all‐metal complexes have aroused our research interest due to their unique structural and properties. Herein, through the facile reduction of μ3‐oxo complex [μ3‐O(PPh3Au)3]+BF4− (1), we synthesized and isolated the triphenylphosphine stabilized triangular tri‐gold complex [(PPh3Au)3]+BF4− (2) for the first time (yield=90 %). Both complexes showed interesting photochemical sensitivity to temperatures and solvents. The cyclic voltammetry of these complexes showed one single oxidation process in CH3CN. These tri‐gold complexes (2 mol % based on the complex itself) were further applied in the catalytic hydroaminations for substituted phenylacetylenes with anilines and gave the corresponding imine products with great catalytic reactivity and regioselectivity without aiding any promoters or additives. When the loading of the tri‐gold complexes was decreased to 1.0 mol%, 95 % and 97 % of conversions were obtained using 1 and 2, respectively. When further decreased the catalyst loading to 0.5 mol% in preparative scale, 83 % and 80 % of isolated yields were achieved, respectively. This method presented great significance for the syntheses of a series of imine‐containing pharmaceutical intermediates even in preparative scale. Moreover, the investigations of catalytic mechanisms of this reaction indicated that these tri‐gold complexes played important roles as efficient pre‐catalysts in hydroaminations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dye-sensitized solar cells (DSSCs) • Using DFT and TD-DFT, to investigate the impact of the diphenylamine moieties on the planarity, photochemical and photophysical properties of a modeled dyes. • The dyes all have donor and acceptor groups linked by a π-linker group (D-π-A). • Designed dyes have smaller energy band-gap, larger λ max , higher electron-donating power, and higher electron-accepting power. • All the dyes have the potential to be used as photosensitizers in DSSCs. Dye-sensitized solar cells (DSSCs) play a significant role in the development of affordable, safe, and efficient solar energy technology. In this research, we have designed nine new dyes (J01-09) by modifying an experimentally reported thiophene-based dye (DSS) in the literature. The diethylaniline in the DSS as the electron donating group was replaced with diphenylamine to reduce planarity in the dye. The designed dyes all have donor and acceptor groups linked by a π-linker group (D-π-A). Using DFT and TD-DFT, we investigated the impact of the diphenylamine moieties on the planarity, photochemical and photophysical properties of the modeled dyes in isolation. The optimized structures, UV–Vis absorption, photochemical, and photovoltaic parameters were computed to study the photosensitizing capability of the modeled dyes. The photochemical and photovoltaic parameters of the study include; open-circuit voltage (V OC), light-harvesting efficiency (LHE), driving force of electron injection (ΔGinj), driving force of regeneration (ΔGreg), excited-state lifetime (τ), ionization potential (IP), adiabatic ionization potential (AIP), vertical ionization potential (VIP), electron affinity (EA), chemical hardness (η), electrophilicity index (ω), electron-donating power (ω-) and electron-accepting power (ω+) were calculated. Our findings indicate that only J03 and J08 absorb at longer wavelengths (719 and 753 nm respectively) indicating lower absorption energy bandgap compared to the DSS dye, attributed to the extension of conjugation between the thiophene and donor groups. Also, only J03 and J08 exhibited lower ΔGinj values (−0.985 and −0.667 eV respectively) and ΔGreg values (0.245 and 0.179 eV respectively) implying the dyes can be regenerated spontaneously compared to the DSS dye. Therefore, J03 and J08 are more promising to be developed as a superior photosensitizer in DSSCs. [ABSTRACT FROM AUTHOR]

The current study describes the synthesis, electrochemical, computational, and photochemical properties of octa (3-hydroxypropylthio) substituted cobalt (II) (4), copper (II) (5), nickel (II) (6) and zinc(II) (7) phthalocyanine derivatives. These novel compounds were characterized by elemental analysis, ¹H, ¹3C NMR, FT-IR, UV-Vis, and MS. The redox behaviors of these metallophthalocyanines were investigated by the cyclic voltammetric method. The optimized molecular structure and gauge-including atomic orbital (GIAO) ¹H and ¹3C NMR chemical shift values of these phthalocyanines in the ground state had been calculated by using B3LYP/6--31G(d,p) basis set. The outcomes of the optimized molecular structure were given and compared with the experimental NMR values. The photochemical properties including photodegradation and singlet oxygen generation of zinc(II) phthalocyanine were studied in DMSO solution for the determination of its photosensitizer behaviors. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a non-invasive therapeutic modality based on the interaction between a photosensitive molecule called photosensitizer (PS) and visible light irradiation in the presence of oxygen molecule. Protoporphyrin IX (PpIX), an efficient and widely used PS, is hampered in clinical PDT by its poor water-solubility and tendency to self-aggregate. These features are strongly related to the PS hydrophilic–lipophilic balance. In order to improve the chemical properties of PpIX, a series of amphiphilic PpIX derivatives endowed with PEG550 headgroups and hydrogenated or fluorinated tails was synthetized. Hydrophilic–lipophilic balance (HLB) and log p-values were computed for all of the prepared compounds. Their photochemical properties (spectroscopic characterization, photobleaching, and singlet oxygen quantum yield) were also evaluated followed by the in vitro studies of their cellular uptake, subcellular localization, and photocytotoxicity on three tumor cell lines (4T1, scc-U8, and WiDr cell lines). The results confirm the therapeutic potency of these new PpIX derivatives. Indeed, while all of the derivatives were perfectly water soluble, some of them exhibited an improved photodynamic effect compared to the parent PpIX.

Quinoline Schiff bases display potential applications in optoelectronics and laser fields because of their unique optical properties that arise from extensive delocalization of the electron cloud, and a high order of non-linearity. In this context, a new class of conjugated quinoline-derivative viz. N-(quinolin-3-ylmethylene)anilines were synthesized from 2-hydroxyquinoline-3-carbaldehyde in two good yielding steps. The ability of these imines to accept an electron from a donor is denoted by their electron acceptor number and sites, which is calculated using density functional theory (DFT). The optical properties such as FT-IR, Raman, UV-VIS, and EDS spectra were calculated using TD-DFT, which also provided the energy gap, HOMO-LUMO structure. The optical properties of the synthesized imino quinolines were experimentally studied using photoluminescence and absorption spectroscopy. The properties such as Stokes shift and quantum yield were calculated using experimental data. Furthermore, the compound bearing a methyl group on the aryl ring and ZnO nanoparticles (hydrothermally synthesized) were dissolved in toluene, and optically excited with a 355 nm nanosecond laser, which produced a random laser.

This article in view of the Compound 1 to Compound 6 (six) kinds of organic small molecule photovoltaic material preparation, thermal properties, UV-vis absorption spectroscopy, fluorescence spectroscopy, electrochemical properties and its ontology with PC60BM heterostructure of solar cell device is analyzed, in order to explore the performance differences of different organic small molecules, provide theoretical guidance for the preparation and development of photovoltaic materials. The results show that increase in the compound rigid structure helps to improve its thermal stability. The UV absorption spectra and fluorescence spectra of organic photovoltaic small molecules are mainly determined by receptor units, when the receptor cell contains three different kinds of donor cells of organic small molecule optical performance difference is not very big, and the UV absorption spectrum of DPP series is wider than that of the benzothiadiazole series. The bandgap size of the six compounds containing triphenylamine depends mainly on the narrow band gap in the small molecule; the triphenylamine is stronger than the carbazole hole transport capacity and fluorene, but its solubility is relatively poor; the DPP series of optical performance and benzothiadiazole is better, but the PV performance is not as benzothiadiazole series. [ABSTRACT FROM AUTHOR]

Abstract The aim of the present paper was to optimize the properties of phenothiazine photosensitizers (PSs), Azure B and its monobrominated derivative. They were entrapped in multilamellar liposomes of egg phosphatidylcholine (EPC) and dipalmitoylphosphatidylcholine (dpPC). The higher partition coefficient of both PSs in the EPC/water system compared with that of both PSs in the dpPC/water system allowed the selection of EPC to be used for the development of third generation photosensitizers. The optimal phospholipid/phenothiazine ratio and the location of these dyes in the lipid bilayer systems were established. These dyes were found to be located within the polar head group region of the lipid bilayer, which would enhance the effectiveness of the irradiation procedure. In addition, the encapsulation of both photosensitizers in liposomes led to a decrease in the aggregation of these compounds, and consequently to an increase in their singlet oxygen quantum yield (ϕ Δ). The encapsulation of the PSs in lipid vesicles significantly increased their photochemical reactivity, doubling the ϕ Δ value of AzBBr and increasing that of AzB by 60%. The results obtained demonstrate that the vehiculization of these PSs in liposomes allowed the development of third generation photosensitizers with better photochemical properties to be used in potential therapeutic applications. Highlights • Azure B and its monobrominated derivative were encapsulated in multilamellar liposomes. • Liposome encapsulation decreased the aggregation of phenothiazine dyes. • Encapsulated photosensitizers exhibited higher singlet oxygen quantum yield. [ABSTRACT FROM AUTHOR]

In this work we report preliminary results obtained for methacrylic polymers incorporating aurone side-group as photochemical active molecule. The aurone polymers were obtained by a three-step synthetic approach: (2Z)-6-hydroxy-2-(4-R-benzyliden)-1-benzofuran-3(2H)-ones were synthesized by using condensation reation of 6-hydroxybenzofuran-3-one with benzaldehydes; then methacrylate monomers were synthesized by reaction the alcohols with methacryloyl chloride; and the polymers were synthesized by free radical polymerization. Polymers were characterized by 1HNMR spectroscopy and DSC techniques. Their physicochemical properties are determined by absorption, fluorescence excitation and emission spectroscopies. [ABSTRACT FROM AUTHOR]

Arsenic (As) presents high toxicity and strong carcinogenicity, and its health risks are regulated by its oxidation state and speciation. As can form complexes with the surface of minerals or organic matter through adsorption, affecting its toxicity and bioavailability. However, the regulation effect of the interaction of coexisting minerals and organic matter on As fate remains largely unknown. Here, we discovered that minerals (e.g., pyrite) and organic matter (e.g., alanyl glutamine, AG) can form pyrite-AG complexes, promoting As(III) oxidation under simulated solar irradiation. The formation of pyrite-AG was explored in terms of the interaction of surface oxygen atoms, electron transfer and crystal surface changes. From the perspective of atoms and molecules, pyrite-AG showed more oxygen vacancies, stronger reactive oxygen species (ROS) and a higher electron transport capacity than pyrite alone. Compared with pyrite, pyrite-AG effectively promoted the conversion of highly toxic As(III) to less toxic As(V) due to the enhanced photochemical properties. Moreover, quantification and capture of ROS confirmed that hydroxyl radicals (•OH) played an important role in As(III) oxidation in the pyrite-AG and As(III) system. Our results provide previously unidentified perspectives on the effects and chemical mechanisms of highly active complexes of mineral and organic matter on As fate and provide new insights into the risk assessment and control of As pollution. [Display omitted] • Pyrite and alanyl glutamine (AG) formed pyrite-AG complexes in water. • Pyrite-AG enhanced photochemical properties and As adsorption sites. • ROS generated by pyrite-AG was 25.41–30.61% higher than that generated by pyrite. • Pyrite-AG significantly (p < 0.05) promoted As(III) oxidation compared with pyrite. [ABSTRACT FROM AUTHOR]

[Display omitted] • The photophysical properties of heterocyclic analogs of 1,4-cyclohexadiene were studied by theoretical calculation and experiment. • Their photophysical and photochemical properties were found to be related to the incorporation of different heteroatoms on the 1,4-cyclohexadiene ring. • The photophysical properties of heterocyclic analogs of 1,4-cyclohexadiene are meaningful for explaining their photochemical reactivity. The photophysical and photochemical properties of a series of heterocyclic analogs of 1,4-cyclohexadiene were studied by theoretical calculation and experiment. With the incorporation of different heteroatoms, the analogs presented distinct photophysical and photochemical properties from 1,4-cyclohexadiene. Their ultraviolet–visible absorption spectra were measured and found to be related to the heteroatoms on the 1,4-cyclohexadiene ring. Calculation of the geometrical and electronic structures of the ground-states revealed that incorporation of the heteroatom affected the photophysical properties of the molecule. The de-excitation processes and electron transition modes were discussed according to the calculated values of the spin–orbit coupling matrix and the electron-hole distributions of the excited states. The reactive sites and geometrical structures showed that incorporation of a heteroatom into 1,4-cyclohexadiene changed the spin density distribution and thus influenced the photochemical properties. These findings are meaningful in explaining the photo-reactivities of these molecules, and provide foundations for further experimental/theoretical investigations and pharmacological applications based on established structure–property correlations. [ABSTRACT FROM AUTHOR]

The development of industry and the increase in population have caused energy shortages and environmental pollution problems. Developing clean and storable new energy is identified as a key way to solve the problems above. Hydrogen is viewed as the most potential energy carrier due to its high calorific value and pollution-free. To convert solar energy into hydrogen energy, three nickel-based catalysts, Ni(aps)(pys) 2 (aps=2-amino-2-phenylacetic salicylaldehyde) (1), Ni(ads)(pys) 2 (ads=aniline salicylaldehyde, pys=pyridine-2-thiolate) (2), Ni(acs)(pys) 2 (acs=aniline 5-chlorosalicylaldehyde) (3), were synthesized and explored as photocatalysts for hydrogen production. A three-component photocatalytic system for hydrogen production was constructed using target complex as photocatalyst, triethanolamine (TEOA) as electron sacrificial agent and fluorescein (FL) as photosensitizer. Under the optimum conditions, about 1504 μmol of H 2 can be obtained with 25 mg catalyst 2 after 3 hours of irradiation. Finally, the hydrogen-production mechanism was discussed by experimental and theoretical methods., (© 2023 Wiley-VCH GmbH.)

The photochemical properties of 1-aryl-2,4,6-triphenyl-1,4-dihydropyrazines 1 were investigated in conventional solvents. The results demonstrated that 1 were unstable to form N-arylbenzamide 2 and N-arylbenzenecarboximidic acid 3 under irradiation with UV light. The photoreaction mechanism was proposed via a photooxygenation. The photoreaction products were determined by ¹H and 13C NMR, high-resolution mass spectrometry (HRMS), and single crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

As a new zero-dimensional carbon-based material, carbon dots (CDs) have attracted extensive attention owing to their advantages such as easy preparation and surface modification, good biocompatibility and water solubility, and tunable photochemical properties. CDs have become one of the most promising nanomaterials in the field of fluorescent sensing, bioimaging, and cancer therapy. How to precisely regulate the photochemical properties, especially the absorption, fluorescence, phosphorescence, reactive oxygen species generation, and photothermal conversion of the CDs, is the key to developing highly efficient phototheranostics for cancer treatment. Although many studies on cancer therapy using CDs have been published, no review has focused on the regulation of photochemical properties of CDs for phototheranostic applications. In this review, we summarized the strategies such as the selection of suitable carbon source, heteroatomic doping, optimum reaction conditions, surface modification, and assembly strategy to efficiently regulate the photochemical properties of the CDs to meet the requirements of different practical applications. This review might provide some valuable insight and new ideas for the development of CDs with excellent phototheranostic performance. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > In Vivo Nanodiagnostics and Imaging., (© 2022 Wiley Periodicals LLC.)

Photodynamic therapy (PDT) is a non-invasive therapeutic modality based on the interaction between a photosensitive molecule called photosensitizer (PS) and visible light irradiation in the presence of oxygen molecule. Protoporphyrin IX (PpIX), an efficient and widely used PS, is hampered in clinical PDT by its poor water-solubility and tendency to self-aggregate. These features are strongly related to the PS hydrophilic–lipophilic balance. In order to improve the chemical properties of PpIX, a series of amphiphilic PpIX derivatives endowed with PEG550 headgroups and hydrogenated or fluorinated tails was synthetized. Hydrophilic–lipophilic balance (HLB) and log p-values were computed for all of the prepared compounds. Their photochemical properties (spectroscopic characterization, photobleaching, and singlet oxygen quantum yield) were also evaluated followed by the in vitro studies of their cellular uptake, subcellular localization, and photocytotoxicity on three tumor cell lines (4T1, scc-U8, and WiDr cell lines). The results confirm the therapeutic potency of these new PpIX derivatives. Indeed, while all of the derivatives were perfectly water soluble, some of them exhibited an improved photodynamic effect compared to the parent PpIX. [ABSTRACT FROM AUTHOR]

Quinoline Schiff bases display potential applications in optoelectronics and laser fields because of their unique optical properties that arise from extensive delocalization of the electron cloud, and a high order of non-linearity. In this context, a new class of conjugated quinoline-derivative viz. N-(quinolin-3-ylmethylene)anilines were synthesized from 2-hydroxyquinoline-3-carbaldehyde in two good yielding steps. The ability of these imines to accept an electron from a donor is denoted by their electron acceptor number and sites, which is calculated using density functional theory (DFT). The optical properties such as FT-IR, Raman, UV-VIS, and EDS spectra were calculated using TD-DFT, which also provided the energy gap, HOMO-LUMO structure. The optical properties of the synthesized imino quinolines were experimentally studied using photoluminescence and absorption spectroscopy. The properties such as Stokes shift and quantum yield were calculated using experimental data. Furthermore, the compound bearing a methyl group on the aryl ring and ZnO nanoparticles (hydrothermally synthesized) were dissolved in toluene, and optically excited with a 355 nm nanosecond laser, which produced a random laser. [ABSTRACT FROM AUTHOR]

• The porous S-doped ZnO nanowires were fabricated by direct reaction of zinc foil. • The as-synthesized S-doped ZnO nanowire represents a half-arc mesoporous superstructure. • An enhanced photochemical property was observed in the as-prepared nanowires. • The S-doped ZnO nanowires have potential applications in optoelectronic applications. The photochemical properties of nanomaterials have always been a research focus in the preparation and optoelectronic applications of nanomaterials. In this work, the porous S-doped ZnO nanowires with cigarette shape were firstly fabricated by direct reaction of zinc foil in aqueous solution of sodium hyposulfite at constant temperature (65 °C). It can be determined that the as-synthesized nanomaterial is elemental S-doped ZnO nanowire with a half-arc mesoporous superstructure characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersion spectroscopy (EDX). Further, through the characterization of photochemical properties, an enhanced photochemical property was observed, indicating the S-doped ZnO nanowire with half-arc mesoporous superstructur have potential applications in dye sensitized photoelectrochemical cells, gas sensors, biosensors, optoelectronic devices, and so on. [ABSTRACT FROM AUTHOR]

• The photochemical properties of Fe(III)-Aspartate complex under irradiation were investigated. • Upon irradiation, the Fe(III)-Aspartate complex undergoes photolysis leading to formation of reactive oxygen species (ROS). • Paracetamol degradation was investigated in the presence of a Fe(III)-Aspartate complex. • Paracetamol degradation was found to amount 80 % at pH = 2.00 and 59 % at pH = 3.00 after 300 min upon UVA irradiation. In this study, the photochemical properties of Fe(III)-Aspartate complex (Fe(III)-Asp) and its performance for the degradation of paracetamol (PC) in aqueous solution under UVA irradiation has been investigated. First, the Fe(III)-Aspartate complex was characterized using UV–vis absorption; the results confirmed that the complex was stable (Log β = 13.81), with molar ratio Fe(III) : Asp = 1:1. Upon irradiation, the Fe(III)-Asp complex undergoes photolysis leading to the formation of reactive oxygen species (ROS) such as HO. Moreover, this photochemical transformation is dependent on the irradiation wavelength and pH. The direct photolysis of paracetamol after 300 min under UVA irradiation showed a negligible effect, while 80 %, 59 %, and 15 % of paracetamol was eliminated in the presence of Fe(III)-Asp complex at pH = 2.05, 3.10, and 4.05; respectively. The degradation was investigated using various parameters such as initial pH, complex concentration, Fe(III):Asp molar ratio, and paracetamol concentration. The use of tert -butyl alcohol as a scavenger confirmed the participation of HO in paracetamol elimination. Addition of Zn (II) and Mn (II) to the system paracetamol-Fe(III)-Asp/UVA showed no significant effect on the degradation, however, Cu (II) had a slightly inhibiting effect. This study highlights the important role that organic iron complexes can play on the fate of pharmaceutical pollutants in aquatic environments. [ABSTRACT FROM AUTHOR]

• UV/chlorine treatment significantly decreased the absorbance of the selected DOM. • Formation of hydroxylated or chlorinated products decreased the Φ RIs of DOM. • Formation of aromatic ketone or quinone increased the Φ RIs of DOM. • DOM more efficiently promote photodegradation of BZF after UV/chlorine treatment. Dissolved organic matter (DOM) is a ubiquitous component in effluents, DOM discharged with an effluent can affect the composition and properties of natural DOM in the receiving waters. As the photophysical and photochemical properties of effluent DOM can be changed by wastewater treatment processes, the effect of UV/chlorine treatment on the photophysical and photochemical properties of DOM was investigated using Suwannee River fulvic acid (SRFA) and Suwannee River natural organic matter (SRNOM) as representatives. Results showed that the absorbance of the two DOM was significantly decreased. The evolution trends of three representative photophysical parameters upon increase of chlorine dosages were observed. Also, a decrease in DOM aromaticity, molecular weight and electron-donating capacity was observed upon increasing chlorine dosage. Quantum yields of excited triplet state of DOM (3DOM*), singlet oxygen (1O 2) and hydroxyl radicals (· OH) first decreases and then increased in the UV/chlorine systems upon increasing chlorine dosages due to the different reaction pathways of the two DOM. Moreover, 3DOM* can not only be regarded as a "controller" of other reactive intermediates, but also effectively promote the photodegradation of bezafibrate, which is classified as a persistent organic contaminant. This study gives deep insights into effects of UV/chlorine on the photophysical and photochemical properties of DOM, and is helpful for understanding the dynamic roles of DOM in the photodegradation of micropollutants. Image, graphical abstract [ABSTRACT FROM AUTHOR]

We investigated the thermal behavior of bimetallic Bi–Mo and Bi–W carbonyl complexes, [Mo(CO) 5 (BiPh 3)] and [W(CO) 5 (BiPh 3)] respectively, to understand the mechanism of decomposition. TGA-DTA, TGA-MS, FTIR, powder XRD and EDX were used to analyze these compounds at different temperatures. At elevated temperature (~150 °C) loss of the M(CO) 5 (M = Mo, W) group occurs first, followed by the loss of phenyl groups at ~300 °C, resulting in the formation of yellow Bi 2 O 3 in presence of air. Additionally, we studied the photochemical behavior of these bimetallic Bi–Mo and Bi–W carbonyl complexes. UV irradiation of these compounds caused the loss of the metal carbonyl, resulting in the formation of BiPh 3. Image 1 • Thermal and photochemical behavior of bimetallic carbonyl compounds [Mo(CO) 5 (BiPh 3)] and [W(CO) 5 (BiPh 3)] were studied. • The Bi-M bond is the weakest in both compounds and at ~150 °C this bond cleaves first, resulting in loss of metal carbonyl. • The loss of phenyl groups occurs at ~300 °C, resulting in the formation of yellow Bi 2 O 3 in presence of air. • UV irradiation of these compounds caused the loss of the metal carbonyl, resulting in the formation of BiPh 3. [ABSTRACT FROM AUTHOR]

A review of publications on the synthesis and properties of a family of compounds called perinones was carried out. The basic molecule has been known for several decades mainly as a photostable pigment, and in recent years it has become increasingly used in organic electronics. This paper describes the methods of synthesis of low molecular weight compounds and polymers based on that molecule; the basic spectroscopic, photochemical, electrochemical and electronic properties important for the construction of organic electronics and optoelectronics devices are also discussed.

The study aimed to improve the efficiency of singlet oxygen by using the ultrasound and so calculated the singlet oxygen with both photochemical and sono-photochemical studies in DMSO and DMF. According to the results, the Φ Δ values in the photochemical studies significantly increased in the sono-photochemical studies, which is evidence that the sono-photochemical study improves the therapeutic activity. • Synthesis and characterization of di-axially 5-Bromo-2-hydroxypyridine substituted silicon (IV) phthalocyanine. • Comparison of singlet oxygen efficiency obtained by sono-photochemical and photochemical activities. • Investigation of aggregation and photophysico-chemical properties of highly soluble silicon phthalocyanine. Sono-photodynamic therapy (SPDT) is a favorable new modality for the treatment of the tumor cells. Although SPDT improves the therapeutic outcomes in cell applications, unlike PDT, SPDT studies are insufficient. In this study, to contribute to the development of SPDT, a promising sensitizer was synthesized, characterized, and analyzed photophysico-chemical properties. Afterwards, the singlet oxygen quantum yield of the sensitizer was calculated by both photochemical and sono-photochemical studies. When the methods are compared, the sono-photochemical studies (Φ Δ = 0.71 in DMSO, 0.65 in DMF) were found more effective than the photochemical studies (Φ Δ = 0.47 DMSO, 0.41 in DMF) in terms of producing singlet oxygen. This report will pave the way for the synthesis of new sensitizers to be used in SPDT. [ABSTRACT FROM AUTHOR]

To face the challenges of optimizing the properties of the photosensitizers currently used in the photodynamic inactivation of various microorganisms, we propose the bromination of thionine and the use of polymeric nanoparticles for the entrapment of halogenated derivative. Within this framework, the dibrominated derivative of thionine was synthesized and characterized. This new compound showed a high chemical and photochemical stability. In addition, bromination decreased the ionization constant and increased the aggregation of this photosensitizer in an aqueous medium. For this reason, the new compound showed a lower quantum yield of singlet oxygen production. However, the dibrominated thionine showed greater cell damage after photodynamic treatment. In order to prevent or decrease the aggregation of the photosensitizer in an aqueous medium, it was vehiculized in different polymeric polyacrylamide nanoparticles. In general, the vehiculization of the photosensitizers (PSs) in nanosized systems increased the production of singlet oxygen and enhanced their phototoxic activity against the microorganisms evaluated (methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus). The nanoparticle formed with the monomer 2 hydroxyethyl methacrylate (HEMA) showed the best photodynamic efficacy. The results obtained clearly suggest that polyacrylamide nanoparticles loaded with photosensitizers of the thiazine family have great potential for further application in antimicrobial photodynamic therapy. Unlabelled Image • The bromination was used for the design of a new second generation photosensitizer. • Properties of the dibrominated thionine were studied. • Polymeric nanoparticles were used to optimize properties of the new photosensitizer. • Photodynamic activity was evaluated against different strains of S. aureus. [ABSTRACT FROM AUTHOR]

Nanoporous TiO 2 spheres have emerged recently as a new class of TiO 2 nanomaterials for photochemical applications. Compared with conventional TiO 2 nanoparticles, the spherical assemblies consisting of low-dimensional nanocrystallites present significant advantages in terms of structural isotropy, monodisperse nature, structural diversity on nano- and (sub)micro-scales, structural stability, light harvesting property, interconnected nanobuilding blocks with less grain boundary, and easy reclaim. Superior performances have been demonstrated in the fields of photoelectrocatalysis and photovoltaics. Research efforts have been devoted to the rational design of a synthetic strategy for the facile preparation of nanoporous TiO 2 spheres. The last decade has witnessed rapid progress in developing a synthesis strategy of nanoporous TiO 2 spheres for optimal photochemical applications. Both chemical and physical routes have been extensively developed aiming to ease control over the self-assembly of nanobuilding blocks and, thus, the resultant textural properties and physicochemical performances of the nanoporous TiO 2 spheres. In this review, a comprehensive description of different synthetic strategies is first presented, with a special emphasis on the formation mechanism, in particular, the pathway followed by nanocrystallites to self-assemble into a spherical structure. Notable experimental parameters are also discussed for the reproducible and controllable preparation of nanoporous TiO 2 spheres with well-defined hierarchical structure, tunable porous microstructure from assembled nanobuilding blocks, and optimal physicochemical properties. Important applications in environmental photocatalysis, solar fuel synthesis, dye-sensitized solar cells (DSCs), and perovskite solar cells (PSCs) are summarized, and the synthesis-component-structure-property relationship in nanoporous TiO 2 spheres is highlighted. Finally, perspectives in this rapidly developing field are offered. [ABSTRACT FROM AUTHOR]