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Glioblastoma multiforme (GBM), the most aggressive form of brain cancer, poses substantial challenges to effective treatment due to its complex and infiltrative nature, making it difficult to manage. Photodynamic therapy (PDT) and sonodynamic therapy (SDT), have emerged as promising individual treatment options against GBM due to their least-invasive approach. However, both PDT and SDT have drawbacks that require careful consideration. A combination therapy using light and sound waves has gained attention, offering new avenues to overcome challenges from individual therapies. Sono-photodynamic therapy (SPDT) has been used against various tumours. Researchers are considering SPDT as a favourable alternative to the conventional therapies for GBM. SPDT offers complementary mechanisms of action, including the production of ROS, disruption of cellular structures, and induction of apoptosis, leading to enhanced tumour cell death. This review gives an insight about PDT/SDT and their limitations in GBM treatment and the need for combination therapy. We try to unveil the process of SPDT and explore the mechanism behind improved SPDT-meditated cell death in GBM cells by focusing on the ROS-mediated cell response occurring as a result of SPDT and discussing current modifications in the existing sensitisers for their optimal use in SPDT for GBM therapy. [ABSTRACT FROM AUTHOR]

Dynamic tumor therapies (mainly including photodynamic therapy (PDT) and sonodynamic therapy (SDT)) offer new approaches to cancer treatment. They are often characterized by their noninvasive nature, high selectivity, and low toxicity. Sensitizers are crucial for dynamic therapy. Developing efficient sensitizers with good biocompatibility and controllability is an important aim in dynamic therapy. Porphyrins and metalloporphyrins attract great attention due to their excellent photophysical properties and low cytotoxicity under non-light. Compared to porphyrins, metalloporphyrins show greater potential for dynamic therapy due to their enhanced photochemical and photophysical properties after metal ions coordinate with porphyrin rings. This paper reviews some metalloporphyrin-based sensitizers used in photo/sonodynamic therapy and combined therapy. In addition, the probable challenges and bottlenecks in clinical translation are also discussed. [ABSTRACT FROM AUTHOR]

Energy can exist in nature in a wide range of forms. Energy conversion refers to the process in which energy is converted from one form to another, and this process will be greatly enhanced by energy conversion sensitizers. Recently, an emerging class of new materials, namely liquid metals (LMs), shows excellent prospects as highly versatile materials. Notably, in terms of energy delivery and conversion, LMs functional materials are chemical responsive, heat‐responsive, photo‐responsive, magnetic‐responsive, microwave‐responsive, and medical imaging responsive. All these intrinsic virtues enabled promising applications in energy conversion, which means LMs can act as energy sensitizers for enhancing energy conversion and transport. Herein, first the unique properties of the light, heat, magnetic and microwave converting capacity of gallium‐based LMs materials are summarized. Then platforms and applications of LM‐based energy conversion sensitizers are highlighted. Finally, some of the potential applications and opportunities of LMs are prospected as energy conversion sensitizers in the future, as well as unresolved challenges. Collectively, it is believed that this review provides a clear perspective for LMs mediated energy conversion, and this topic will help deepen knowledge of the physical chemistry properties of LMs functional materials. [ABSTRACT FROM AUTHOR]

The regioselective synthesis of biphenyls, which are economically important pharmaceuticals, agrochemicals, and liquid crystals, is a challenging task. Current methods rely on metal‐dependent cross‐coupling reactions, which unfortunately require the use of harmful halogenated aryls and heavy metal catalysts that are toxic and difficult to remove from the final products. Recently, we have circumvented these problems by developing a metal‐free and broadly applicable photochemical method for biphenyl synthesis using UV−C light, called photosplicing. Here we present an improved method using photosensitizers in combination with UV−B, UV−A light, or sunlight. Using a high‐precision flow reactor with deep‐UV LEDs, we investigated the ability of commonly available organic photosensitizers to enhance the photosplicing reaction and identified a number of suitable photosensitizers with the required triplet energy. This method allows for easy batch synthesis of biaryls in borosilicate glassware and paves the way for their large‐scale production without the need for flow reactors. [ABSTRACT FROM AUTHOR]

Solar energy is an abundant source of energy, and harnessing the sun's radiation with an efficient solar cell can be a promising technology for a limitless supply of sustainable energy. The amount of solar power that reaches the earth is beyond the world's energy consumption. But, the main cause for minimal usage of the sun's energy is the complicated technology, restricted band gap, high-temperature instability, and high cost of production. Likewise, the usage of space and infrastructure required for the installation of solar cells is yet another reason for limited usage. Upon comparing the emerging photovoltaics, DSSC (dye-sensitized solar cells) can be a solution for the drawbacks faced by the older generation solar cells which has greater future scope as an energy harvester. Rapid technological growth over the years, usage of affordable materials, and capability of working efficiently in low lighting conditions make DSSC a commercially viable and potent solar energy harvester. Furthermore, its efficiency can be improved with the inclusion of low-dimensional nanocarbons in various components of DSSC. Therefore, this review describes the mechanisms of improving the performance of zero-dimensional nanocarbons and their application in components of DSSC alternative to conventional materials. The significant impact of surface functionalization of low-dimensional nanocarbon on the performance of dye-sensitized solar cells is also discussed. [ABSTRACT FROM AUTHOR]

Quantum yields, structure, and enzymatic activity points of coumarin–activated C-334 chemiluminescence of lipid peroxidation processes under the action of cytochrome C and cardiolipin complex in aqueous medium and in nonpolar environment were modeled. It is presented for consideration that: (1) quantum yields are significantly higher in the presence of the physical activator coumarin C-334 than in the case of its own unactivated luminescence; (2) enzymatic activity depends not only on the concentration of cytochrome C but also on the percentage ratio between its native and partially denatured forms. [ABSTRACT FROM AUTHOR]

Individual differences in emotional coping styles are likely to affect information processing on different stages. Repressive coping is assumed to be related to an attentional bias away from threatening information. Possible links to biases in later stages of information processing have not been investigated to date. In the current study, 82 participants completed the visual dot-probe task as a measure of attentional bias and the Approach-Avoidance Task (AAT) as a measure of approach/avoidance bias and classified into coping groups via the Mainz Coping Inventory (MCI). Prevalence of attention bias and approach/avoidance bias were compared between groups. Main results revealed a strong approach tendency toward positive stimuli for repressors and a strong avoidance tendency for sensitizers. No group differences were found for approach bias to negative stimuli or for attention bias. The present findings of strong preferential processing of positive stimuli in repressors may be part of broader information processing alterations, which may also be linked to alterations in emotion processing. [ABSTRACT FROM AUTHOR]

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This article reviews the upconversion phosphors based on their ability to emit various peaks corresponding to different colors in the visible range. The review suggests that these upconversion phosphors have a wide range of applications in the field of medical science and display devices especially. The study suggests that Erbium (III) and Ytterbium (III) have the capability to transfer energy gained from the excitation source to other co-dopants. Hence the co-dopants gain additional energy apart from the excitation sources which is usually 980 nm (near IR) and retain more energy than the energy provided by the excitation source. The mechanism of upconversion was also discussed. Most of the research used at least two dopants with the host for preparing an upconversion phosphor when they function like sensitizers and activators. [ABSTRACT FROM AUTHOR]

Anchoring groups are crucial for enhancing the performance of dye-sensitized solar cells (DSSCs). For instance, cyanoacrylic acid serves as the primary anchoring group in DSSC due to its crucial elements required for effective electron transport. However, it suffers from degradation. To address this limitation, this study proposes alternative cyano-based anchoring groups for sensitizers. Density functional theory (DFT) and time-dependent DFT were used to investigate the optical and electronic properties of the dyes. The studied dyes (excluding the dye containing OH group) displayed three absorption bands within the visible and NIR regions. Low-energy peaks ranged from 498 to 576 nm, corresponding to excitation from ground state to first excited state. Moderate intensity bands appeared at 376 to 418 nm, with the highest energy bands falling within 351 to 384 nm. Ground state oxidation potential values for the dyes were lower than the redox potential of the iodide/triiodide pair. Similarly, excited state oxidation potential values were higher than or equal to the conduction band of TiO2, except for NO2 and CHO containing dyes. Ionization potential values ranged from 6.24 eV to 6.40 eV, while electron affinity values were within 1.21 eV to 2.74 eV. Chemical potential values ranged from 3.75 to 4.57 eV, and chemical hardness of the dyes fell between 1.83 to 2.54 eV. The proposed cyano-based anchoring groups show promising potential for enhancing DSSC performance. [ABSTRACT FROM AUTHOR]

Introduction: Previous research suggested differential stress reactivity depending on individuals' coping style, e.g., as classified by the model of coping modes. Specifically, stronger physiological reactivity and weaker subjective stress ratings were found for repressors than for sensitizers. However, it remains to be investigated (i) whether these findings, which are largely based on social stress induction protocols, also generalize to other stressors, (ii) whether repressors vs. sensitizers also exhibit differential stress recovery following the application of a relaxation method, and (iii) which stress reactivity and recovery patterns are seen for the two remaining coping styles, i.e., fluctuating, and non-defensive copers. The current study thus examines stress reactivity in physiology and subjective ratings to a non-social stressor and the subsequent ability to relax for the four coping groups of repressors, sensitizers, fluctuating, and non-defensive copers. Methods: A total of 96 healthy participants took part in a stress induction (Mannheim Multicomponent Stress Test) and a subsequent relaxation intervention. Subjective ratings of stress and relaxation, heart rate (HR), heart rate variability (HRV), and blood pressure were assessed during the experiment. HR and blood pressure are markers of the sympathetic stress response that can be regulated by relaxation, while HRV should increase with relaxation. To investigate long-term relaxation effects, subjective ratings were also assessed on the evening of testing. Results: Despite successful stress induction, no differential responses (baseline to stress, stress to relaxation) were observed between the different coping groups on any of the measures. In contrast, a strong baseline effect was observed that persisted throughout the experiment: In general, fluctuating copers showed lower HR and higher HRV than non-defensive copers, whereas repressors reported lower subjective stress levels and higher levels of relaxation during all study phases. No differences in subjective ratings were observed in the evening of testing. Conclusion: Contrary to previous research, no differential stress reactivity pattern was observed between coping groups, which could be due to the non-social type of stressor employed in this study. The novel finding of physiological baseline differences between fluctuating and non-defensive individuals is of interest and should be further investigated in other stressor types in future research. [ABSTRACT FROM AUTHOR]

The application of wide-gap semiconductor nanoparticles for improving optical characteristics of dye-sensitized solar cells (DSSCs) is considered. Here, silicon carbide nanoparticles (nSiC) are used as wide-gap quantum dots, and chromophores (lutetium diphthalocyanine and delphinidin) play the role of sensitizers. The influence of SiC nanoparticles on the absorption spectra of chromophores in tetrahydrofuran solutions, as well as their direct influence on substrates with titanium dioxide after introduction of sensitizers, is investigated. The characteristics of designed DSSCs are measured, and the DSSC performance is estimated based on the measurement data. The DSSC power and efficiency are calculated. It is found that addition of wide-gap semiconductor nanoparticles to a sensitizer improves significantly the characteristics of solar cells and increases essentially their stability. This improvement can be explained by the exciton decay, at which an electron passes initially to a nanoparticle of wide-gap SiC and then to a titanium dioxide (TiO2) nanoparticle. The best characteristics of the solar cell versions under consideration correspond to those obtained for delphinidin with SiC nanoparticles. [ABSTRACT FROM AUTHOR]

Light-activated polymerization is one of the most important and powerful strategies for fabrication of various types of advanced polymer materials. Because of many advantages, such as economy, efficiency, energy saving and being environmentally friendly, etc., photopolymerization is commonly used in different fields of science and technology. Generally, the initiation of polymerization reactions requires not only light energy but also the presence of a suitable photoinitiator (PI) in the photocurable composition. In recent years, dye-based photoinitiating systems have revolutionized and conquered the global market of innovative PIs. Since then, numerous photoinitiators for radical polymerization containing different organic dyes as light absorbers have been proposed. However, despite the large number of initiators designed, this topic is still relevant today. The interest towards dye-based photoinitiating systems continues to gain in importance, which is related to the need for new initiators capable of effectively initiating chain reactions under mild conditions. In this paper we present the most important information about photoinitiated radical polymerization. We describe the main directions for the application of this technique in various areas. Attention is mainly focused on the review of high-performance radical photoinitiators containing different sensitizers. Moreover, we present our latest achievements in the field of modern dye-based photoinitiating systems for the radical polymerization of acrylates. [ABSTRACT FROM AUTHOR]

Properties of a delphinidin complex with silicon carbide nanoparticles have been studied by optical methods. Electron microscopy data have been used to determine the phase composition of silicon carbide samples. A comparative analysis of the absorption spectra of solutions of delphinidin and delphinidin with silicon carbide nanoparticles has shown a marked increase in light absorption in the presence of the nanoparticles. The observed large increase in absorbance attests to a considerable adsorption of delphinidin molecules on the surface of silicon carbide nanoparticles. Combining delphinidin with silicon carbide nanoparticles improves the performance of Grätzel cells compared to the sensitizer without nanoparticles. The addition of silicon carbide nanoparticles to the dye increases the power and efficiency of the Grätzel cell. [ABSTRACT FROM AUTHOR]

This article discusses the prevalence of contact sensitizers in cosmetics marketed as safe for pregnant women. The study analyzed leave-on and rinse-off products available in online drugstores in Poland and found that only 2.5% of the products did not contain haptens, which are substances that can cause allergic reactions. The most common haptens found in the products were perfume, tocopherol, and panthenol. The authors suggest that pregnant and breastfeeding women should carefully examine the composition of these products to minimize the risk of skin sensitization. [Extracted from the article]

Dye-sensitized solar cells (DSSCs) still survive as one of the promising low-cost photovoltaic third-generation technologies, addressing 'secure, clean and efficient solar energy conversion'. Here we present and compare some recent state-of-the-art progress on the exploitation of the best artificial dyes for application in DSSCs. Furthermore, we provide an extensive discussion on the main limitations in the use of these dyes, outlining future developments for their use in bifacial employment exploring their frontal and back irradiation. We report also how to take advantage of the Albedo effect to boost power conversion efficiency. Finally, we present our view on the future prospective in the development of advanced materials for better DSSCs. [ABSTRACT FROM AUTHOR]

While 2‐alk‐ω‐enyloxy‐sustituted benzaldehydes do not display any photochemical reactivity at the arene core, the respective iminium perchlorates were found to undergo efficient reactions either upon direct irradiation (λ=366 nm) or under sensitizing conditions (λ=420 nm, 2.5 mol% thioxanthen‐9‐one). Three pathways were found: (a) Most commonly, the reaction led to benzoxacyclic products in which the olefin in the tether underwent a formal, yet unprecedented carboformylation (13 examples, 44–99 % yield). The cascade process occurred with high diastereoselectivity and was found to be stereoconvergent. (b) If a substituent resides in the 3‐position of the benzene ring, a meta photocycloaddition was observed which produced tetracyclic skeletons with five stereogenic centers in excellent regio‐ and diastereoselectivity (2 examples, 58–79 % yield). (c) If the tether was internally substituted at the alkene, an arene photocycloaddition was avoided and an azetidine was formed in an aza Paternò–Büchi reaction (2 examples, 95–98 % yield). [ABSTRACT FROM AUTHOR]

While 2‐alk‐ω‐enyloxy‐sustituted benzaldehydes do not display any photochemical reactivity at the arene core, the respective iminium perchlorates were found to undergo efficient reactions either upon direct irradiation (λ=366 nm) or under sensitizing conditions (λ=420 nm, 2.5 mol% thioxanthen‐9‐one). Three pathways were found: (a) Most commonly, the reaction led to benzoxacyclic products in which the olefin in the tether underwent a formal, yet unprecedented carboformylation (13 examples, 44–99 % yield). The cascade process occurred with high diastereoselectivity and was found to be stereoconvergent. (b) If a substituent resides in the 3‐position of the benzene ring, a meta photocycloaddition was observed which produced tetracyclic skeletons with five stereogenic centers in excellent regio‐ and diastereoselectivity (2 examples, 58–79 % yield). (c) If the tether was internally substituted at the alkene, an arene photocycloaddition was avoided and an azetidine was formed in an aza Paternò–Büchi reaction (2 examples, 95–98 % yield). [ABSTRACT FROM AUTHOR]

Finding new efficient p‐type sensitizers for NiO photocathodes is a great challenge for the development of promising low‐cost tandem dye‐sensitized solar cells (DSSCs). Now, the focus of researchers investigating these cells has been to create high‐performance p‐type systems. With this intention, herein, the design and synthesis of six new phenoxazine‐based donor–acceptor (D–A)‐configured organic dyes PO1–6 was reported, comprising different acceptor moieties specially designed for the sensitization of mesoporous p‐type semiconductor NiO for the construction of p‐type DSSCs (p‐DSSCs). This work includes structural, photophysical, thermal, electrochemical, theoretical, and photoelectrochemical studies of these dyes, including evaluation of their structure‐property relationships. The optical studies revealed that PO1–6 displayed adequate absorption and emission features in the range of 480–550 and 560–650 nm, respectively, with a bandgap in the order of 2.05–2.40 eV, and their thermodynamic parameters favored an efficient interfacial charge transfer involving NiO. Among the six new dyes, the device based on sensitizer PO2 carrying electron‐withdrawing 1,3‐diethyl‐2‐thiobarbituric acid achieved the highest power conversion efficiency of 0.031 % (short‐circuit current density=0.89 mA cm−2, open‐circuit voltage=101 mV, and fill factor=35 %). Conclusively, the study furnishes an understanding of the intricacies involved in the structural modification of phenoxazine‐based sensitizers to further ameliorate the performance of the p‐type DSSCs. [ABSTRACT FROM AUTHOR]

This work describes the first hot exciton fluorescent material based on benzo[c][1,2,5]thiadiazole and chiral binaphthol enabling circularly polarized luminescence (CPL) through a chiral perturbation strategy. The new molecular architecture displays CPL, hybridized local and charge transfer (HLCT) properties concurrently. Utilizing it as the emitter, circularly polarized organic light‐emitting diodes (CP‐OLEDs) achieve an external quantum efficiency (EQE) of 7.2% with a good exciton utilization (36%) and a moderate circularly polarized electroluminescence (CPEL) dissymmetry factor (gEL, 2.1 × 10−3). In addition, the CP‐HLCT molecule is sensitized by a thermally activated delayed fluorescence material, significantly ameliorating the efficiency of HLCT fluorescent CP‐OLEDs. Excellent performances of twofold maximum EQE (EQEmax) of 15.3% and 82% exciton utilization are obtained in the sensitized device, regarding an extremely low‐efficiency roll‐off of 2.6% at 1000 cd m−2 as well as CPEL with a gEL value of 2.0 × 10−3. [ABSTRACT FROM AUTHOR]

Purely organic emitters have shown great potential but still suffer from low efficiency in near‐infrared organic light‐emitting diodes (NIR‐OLEDs) due to the intensive non‐radiative recombination. In this contribution, two pairs of thermally activated delayed fluorescence (TADF) enantiomers (R/S‐DOBP and R/S‐HDOBP) with tetracoordinate boron geometries were designed and synthesized. The TADF emitters simultaneously showed aggregation‐induced emission, circularly polarized luminescence, high‐contrast mechanochromism, and piezochromism behaviors. More importantly, R/S‐DOBP and R/S‐HDOBP revealed high photoluminescence quantum yields and efficient reverse intersystem crossing in neat films. The nondoped solution‐processed OLEDs based on these unique emitters revealed the NIR emission (peaking at 716 nm) with a maximum external quantum efficiency of 1.9 % and high exciton utilization efficiency of 86 %, which represent one of the best solution‐processed nondoped NIR‐OLEDs. [ABSTRACT FROM AUTHOR]

Purely organic emitters have shown great potential but still suffer from low efficiency in near‐infrared organic light‐emitting diodes (NIR‐OLEDs) due to the intensive non‐radiative recombination. In this contribution, two pairs of thermally activated delayed fluorescence (TADF) enantiomers (R/S‐DOBP and R/S‐HDOBP) with tetracoordinate boron geometries were designed and synthesized. The TADF emitters simultaneously showed aggregation‐induced emission, circularly polarized luminescence, high‐contrast mechanochromism, and piezochromism behaviors. More importantly, R/S‐DOBP and R/S‐HDOBP revealed high photoluminescence quantum yields and efficient reverse intersystem crossing in neat films. The nondoped solution‐processed OLEDs based on these unique emitters revealed the NIR emission (peaking at 716 nm) with a maximum external quantum efficiency of 1.9 % and high exciton utilization efficiency of 86 %, which represent one of the best solution‐processed nondoped NIR‐OLEDs. [ABSTRACT FROM AUTHOR]

Radiant energy (solar energy) plays a vital role due to its continuous power supply and environmentally friendly in meeting the people's energy demand. The need for an endless supply of energy, majorly through solar energy exploitation has driven the expansion and diversification of a device for proper energy storage. This review summarizes a photo-supercapacitor's working mechanism. The classification of a supercapacitor was discussed and the advancements of the active components that makeup a photosupercapacitor and the improvements on photo-supercapacitor in energy storage were highlighted. For the constant generation of electricity, dye-sensitized solar cells (DSSCs) and supercapacitor are incorporated. The invention of hybridized dye-sensitized solar cell (DSSC)-capacitors and DSSC-supercapacitors are crucial in energy storage processes, and the advancement in technology has triggered the creation of a photosupercapacitor for efficient harvesting of energy and proper storage mechanisms. The intent of pairing a DSSC with a supercapacitor for conversion of energy and proper energy storage arose when dye molecules absorb radiant energy and the absorbed energy is transformed to electrical energy. The use of active components of a photo-supercapacitor will determine its conversion efficiency. The performance of active components of photo-supercapacitors such as dye, electrolyte, photoanode, and the counter electrode are the main factors that contribute to efficient conversion of energy to improve the photo-supercapacitor's storage life. [ABSTRACT FROM AUTHOR]

The rapid growth of the population severely influences the supply of energy, accordingly ensuring clean energy has become a big challenge now and will be in the future. Fossil fuels have been satisfying the energy demand until now, but fossil fuels, being non‐renewable sources, will not be able to satisfy the energy demand in the future and will have a negative impact on the environment. Renewable energy sources have become the most demanding topic for researchers in this crisis. The solar cell, which is an abundant renewable energy resource, converts solar power into electrical energy without any environmental damage. Silicon solar cells have higher efficiency, but their high manufacturing cost, complicated procedures and environmental issues restrict their usage. Then dye‐sensitized solar cells (DSSCs) have been introduced as an alternative to silicon solar cells. In DSSC, both natural and synthetic dyes are used. Though synthetic dyes provide higher efficiency, they are environmentally harmful. Afterward, the concept of natural dye‐sensitized solar cells (NDSSC) have been materialized where only natural dyes are used. Researchers and environmentalists are looking for natural dyes as a replacement for synthetic dyes in recent times, as natural dyes are plentiful, can be collected naturally and have no environmental effects. Natural dyes in the form of anthocyanins, carotenoids, flavonoids, chlorophylls, tannins and betalains are extracted from various portions of plants that include leaves, roots, flowers, fruits, seeds, barks, etc. In this review, we investigate natural sources of dyes, natural sensitizers (dyes), shortcomings and remedies, improvements in efficiency and stability, developments, and commercialization. In addition, recent advances and the comparison of natural and synthetic dyes have been discussed in this review. [ABSTRACT FROM AUTHOR]

The photochemical synthesis of yet unknown 2‐oxospiro[azetidine‐3,3′‐indolines] (17 examples, 80–95 % yield), 2,4‐dioxospiro[azetidine‐3,3′‐indolines] (eight examples, 87–97 % yield), and 1‐oxo‐1,3‐dihydrospiro[indene‐2,3′‐indolines] (17 examples, 85–97 % yield) is described. Starting from readily accessible 3‐substituted indoles, a dearomatization of the indole core was accomplished upon irradiation at λ=420 nm in the presence of thioxanthen‐9‐one (10 mol%) as the sensitizer. Based on mechanistic evidence (triplet energy determination, deuteration experiments, by‐product analysis) it is proposed that the reaction proceeds by energy transfer via a 1,4‐ or 1,5‐diradical intermediate. The latter intermediates are formed by excited state hydrogen atom transfer from suitable alkyl groups within the C3 substituent to the indole C2 carbon atom. Subsequent ring closure proceeds with pronounced diastereoselectivity to generate a 4‐ or 5‐membered spirocyclic dearomatized product with several options for further functionalization. [ABSTRACT FROM AUTHOR]

The photochemical synthesis of yet unknown 2‐oxospiro[azetidine‐3,3′‐indolines] (17 examples, 80–95 % yield), 2,4‐dioxospiro[azetidine‐3,3′‐indolines] (eight examples, 87–97 % yield), and 1‐oxo‐1,3‐dihydrospiro[indene‐2,3′‐indolines] (17 examples, 85–97 % yield) is described. Starting from readily accessible 3‐substituted indoles, a dearomatization of the indole core was accomplished upon irradiation at λ=420 nm in the presence of thioxanthen‐9‐one (10 mol%) as the sensitizer. Based on mechanistic evidence (triplet energy determination, deuteration experiments, by‐product analysis) it is proposed that the reaction proceeds by energy transfer via a 1,4‐ or 1,5‐diradical intermediate. The latter intermediates are formed by excited state hydrogen atom transfer from suitable alkyl groups within the C3 substituent to the indole C2 carbon atom. Subsequent ring closure proceeds with pronounced diastereoselectivity to generate a 4‐ or 5‐membered spirocyclic dearomatized product with several options for further functionalization. [ABSTRACT FROM AUTHOR]

At present, metalloporphyrin compounds demonstrate three main uses as anticancer sensitizers: (1) photosensitizers, (2) photothermal conversion agents, and (3) ultrasound sensitizers. Developing efficient sensitizers for cancer with excellent controllability and biocompatibility is an important goal of oncology medicine. Because of the different structural diversity of anticancer sensitizers, such sensitizers are used for treating cancers by employing a variety of tumor treatment methods such as mature photodynamic therapy, commonly used clinically photothermal therapy and promising sonodynamic therapy. Among the many sensitizers, metalloporphyrin-complex sensitizers attract wide attention due to their excellent performance in tumor treatment and diagnosis. This review briefly describes some metalloporphyrin anticancer drugs and diagnostic agents related to photodynamic, photothermal and sonodynamic therapy, and discusses the roles of metal atoms in these drugs. [ABSTRACT FROM AUTHOR]

Multiple resonance (MR) emitters are promising for highly efficient organic light‐emitting diodes (OLEDs) with narrowband emission; however, they still face intractable challenges with concentration‐caused emission quenching, exciton annihilation, and spectral broadening. In this study, sterically wrapped MR dopants with a fluorescent MR core sandwiched by bulk substituents were developed to address the intractable challenges by reducing intermolecular interactions. Consequently, high photo‐luminance quantum yields of ≥90 % and small full width at half maximums (FWHMs) of ≤25 nm over a wide range of dopant concentrations (1–20 wt %) were recorded. In addition, we demonstrated that the sandwiched MR emitter can effectively suppress Dexter interaction when doped in a thermally activated delayed fluorescence sensitizer, eliminating exciton loss through dopant triplet. Within the above dopant concentration range, the optimal emitter realizes remarkably high maximum external quantum efficiencies of 36.3–37.2 %, identical small FWHMs of 24 nm, and alleviated efficiency roll‐offs in OLEDs. [ABSTRACT FROM AUTHOR]

Multiple resonance (MR) emitters are promising for highly efficient organic light‐emitting diodes (OLEDs) with narrowband emission; however, they still face intractable challenges with concentration‐caused emission quenching, exciton annihilation, and spectral broadening. In this study, sterically wrapped MR dopants with a fluorescent MR core sandwiched by bulk substituents were developed to address the intractable challenges by reducing intermolecular interactions. Consequently, high photo‐luminance quantum yields of ≥90 % and small full width at half maximums (FWHMs) of ≤25 nm over a wide range of dopant concentrations (1–20 wt %) were recorded. In addition, we demonstrated that the sandwiched MR emitter can effectively suppress Dexter interaction when doped in a thermally activated delayed fluorescence sensitizer, eliminating exciton loss through dopant triplet. Within the above dopant concentration range, the optimal emitter realizes remarkably high maximum external quantum efficiencies of 36.3–37.2 %, identical small FWHMs of 24 nm, and alleviated efficiency roll‐offs in OLEDs. [ABSTRACT FROM AUTHOR]

Natural dyes extracted from Senna singueana flowers and leaves, Ximenia caffra fruits and Bougainvillea glabra bracts were used as sensitizers to fabricate dye sensitized solar cells (DSSCs). The UV-Vis characterization of these species' crude and purified natural dyes showed that Senna singueana leaves have broad broadband absorption, followed by Bougainvillea glabra bracts. The absorption intensity of Senna singueana leave and Bougainvillea glabra bract for crude and purified dyes was comparable, indicating their potential in DSSCs performance. The photoelectrochemical performance of the selected dyes used as a sensitizer in DSSCs indicated that Senna singueana leaves attained the highest open-circuit voltage (Voc) and short circuit current density (Jsc) of 471 mV and 4.32 mA/cm2 for crude dye, and 355 mV and 4.87 mA/cm2 for purified dye. In contrast, Bougainvillea glabra bract had 380 mV and 3.34 mA/cm2 for crude dye and 75 mV and 1.95 mA/cm2 for purified dye. The photo-to-electric conversion efficiency of the DSSCs based on Senna singueana leaves as sensitizers were 0.68% (crude) and 0.51% (purified) and that of Bougainvillea glabra bract were 0.45% (crude) and 0.04% (purified). To our best knowledge, this is the first time to report the highest efficiency for Senna singueana leave in DSSC. Various organic solvents were used for purification; however, the photoelectrochemical performance of those extracts demonstrated that crude dyes are more effective than purified dyes as sensitizers in DSSCs application. [ABSTRACT FROM AUTHOR]

Energy production must evolve from heavily depending on fossil fuels to renewable resources in order to cease the depletion of those resources. Solar energy development is an alternative to reduce our reliance on fossil fuels which also helps to offset global warming by reducing greenhouse gas emissions. Generally, photovoltaic (PV) cells are classified based on the generation (GEN) or category. Dye-sensitized solar cells (DSSCs) which from the third GEN are still one of the best alternatives over the silicon-devices due to its sustainability and rapid improvement in conversion efficiency. However, there are several factors hampering dependency on DSSCs such as cost and environmental concerns. Therefore, we conducted this systematic literature review based on the Scopus database to find out possible answers for those questions. To the present time, transition metal complexes based on ruthenium (Ru) are the most prevailing sensitizers. However, these noble metal-based devices are not sustainable due to the toxicity and scarcity of Ru metal. Thus, designing alternatives that transcend these drawbacks is worthwhile in the long run. In this context, copper (Cu) complexes become the prominent choice. Other than the economic benefits, Cu complexes mainly Cu(I) polypyridyl-based compounds display numerous photophysical similarities with [Ru(2,2′-bipyridine)3] 2+ such as strong metal-ligand charge transfer (MLCT) absorption in the visible region and a relatively long excitedstate lifetime. In summary, qualities possessed by Cu complexes are excellent as sensitizers and ideal to be the replacement for Ru complexes. [ABSTRACT FROM AUTHOR]

A series of six new Fe(II)NHC‐carboxylic sensitizers with their ancillary ligand decorated with functions of varied electronic properties have been designed with the aim to increase the metal‐to‐ surface charge separation and light harvesting in iron‐based dye‐sensitized solar cells (DSSCs). ARM130 scored the highest efficiency ever reported for an iron‐sensitized solar cell (1.83 %) using Mg2+ and NBu4I‐based electrolyte and a thick 20 μm TiO2 anode. Computational modelling, transient absorption spectroscopy and electrochemical impedance spectroscopy (EIS) revealed that the electronic properties induced by the dimethoxyphenyl‐substituted NHC ligand of ARM130 led to the best combination of electron injection yield and spectral sensitivity breadth. [ABSTRACT FROM AUTHOR]

Homocoupling reactions promoted by photocatalysts are not very abundant in the literature. However, the products generated from such processes are very interesting. In this review, we highlight the most relevant reports concerning photocatalyzed dimerizations covering the literature until the middle of 2020. Reactions will be classified according to the type of starting material employed, with an emphasis being placed on the corresponding mechanism. 1 Introduction 2 Arenes and Heteroarenes 3 Alkenes 4 Alkanes 5 Alkynes 6 Aldehydes, Ketones, Alcohols, Amines and Imines 7 Carboxylic Acids 8 Nitro Compounds 9 Conclusions [ABSTRACT FROM AUTHOR]

A series of piperidine‐naphthalene monoimide, donor−acceptor (D−A) chromophores and their thionated derivatives were prepared. The physical properties of the chromophores were studied by spectroscopic and electrochemical measurements and DFT calculations. Relative to their non‐thionated counterparts, the thionated D−A chromophores display enhanced visible‐light absorption and 1O2‐sensitization quantum yields and negligible fluorescence, suggesting facile triplet formation of this class of molecules. This behavior originates from the significant n‐π* character in the singlet excited state, resulting in large spin‐orbit coupling between the singlet/triplet manifolds regardless of the degree of D/A interactions. With the electrochemically active D/A moieties and high triplet energy, the thionated chromophores can be used as amphoteric photosensitizers to catalyze reductive and oxidative photoreactions with efficiency comparable to Ru(bpy)32+ as the sensitizer. Our results demonstrate that thiocarbonylation can be utilized in amide/imide‐containing D−A chromophores to provide a wide range of heavy‐atom‐free redox‐active photosensitizers. [ABSTRACT FROM AUTHOR]

Lightweight computing technologies such as the Internet of Things and flexible wearable systems have penetrated our everyday lives exponentially in recent years. Without a question, the running of such electronic devices is a major energy problem. Generally, these devices need power within the range of microwatts and operate mostly indoors. Thus, it is appropriate to have a self-sustainable power source, such as the photovoltaic (PV) cell, which can harvest indoor light. Among other PV cells, the dye-sensitized solar cell (DSSC) has immense capacity to satisfy the energy demands of most indoor electronics, making it a very attractive power candidates because of its many benefits such as readily available materials, relatively cheap manufacturing methods, roll-to-roll compatibility, easy processing capabilities on flexible substrates and exceptional diffuse/low-light performance. This review discusses the recent developments in DSSC materials for its indoor applications. Ultimately, the perspective on this topic is presented after summing up the current progress of the research. [ABSTRACT FROM AUTHOR]

Summary: In the present context of increasing population, renewable and sustainable energy alternatives are very much essential to satisfy the necessities of the world. To satisfy this growing demand, scientists are prioritizing the production of cost‐effective and high‐performance clean energy appliances. Dye‐sensitized solar cells (DSSCs) are one such material that is at the forefront of modern solar cell technologies. Being one of the main components of DSSCs, metal‐free organic dyes play a crucial role in light processing and electron injection. In recent times, carbazole (CZ)‐, triphenylamine (TPA)‐, and phenothiazine (PTZ)‐based derivatives have been identified as suitable alternatives to Ru(II) polypyridyl complexes because they are easy to synthesize and exhibit excellent thermal and electronic properties. This review focuses largely on the latest developments in the use of monoanchored and multianchored CZ, TPA, and PTZ scaffolds for DSSC applications and focuses especially on the correlation between molecular design and photovoltaic performance. The physical properties of devices can be adjusted through the sensitizer's strategic design that helps to improve the performance of the devices. We tabulated the photovoltaic parameters corresponding to all dyes presented in this review. Also, applications of additives are presented after the systematic review on CZ‐, TPA‐, and PTZ‐based dyes. [ABSTRACT FROM AUTHOR]

The utilization of solar energy via photoelectrochemical cells (PEC) towards hydrogen (H2) production is a promising approach in the field of artificial photosynthesis. In this work, the synthesis and complete characterization of the first covalently linked porphyrin‐cobalt diimine‐dioxime dyad (ZnP‐Co) is reported. The synthetic procedure that was followed is based on simple and high yielding reactions, without using any noble metal. Photophysical investigation of the dyad revealed sufficient electronic communication between the sensitizer and the catalyst in the excited state. Finally, NiO films were sensitized with ZnP‐Co and the H2‐evolving photoelectrochemical activity of the resulting photocathode was assessed. The modest performances could be rationalized thanks to photolysis and post‐operando characterizations of the system, thus providing some guidelines toward the design of more efficient porphyrin‐based assemblies. [ABSTRACT FROM AUTHOR]

In this work, a design approach of three thermally activated delayed fluorescence (TADF) emitters to extend the device lifetime of the TADF sensitized fluorescent devices was studied. Three TADF materials, 5‐{4,6‐bis[4‐(tert‐butyl)phenyl]‐1,3,5‐triazin‐2‐yl}‐2‐(10,15‐diphenyl‐10,15‐dihydro‐5H‐diindolo[3,2‐a:3′,2′‐c]carbazol‐5‐yl)benzonitrile (tTCNTruX), 4‐[3‐cyano‐4‐(10,15‐diphenyl‐10,15‐dihydro‐5H‐diindolo[3,2‐a:3′,2′‐c]carbazol‐5‐yl)phenyl]‐2,6‐diphenylpyrimidine‐5‐carbonitrile (PCNTruX) and 4‐(4‐{10,15‐bis[4‐(tert‐butyl)phenyl]‐10,15‐dihydro‐5H‐diindolo[3,2‐a:3′,2′‐c]carbazol‐5‐yl}‐3‐cyanophenyl)‐2,6‐diphenylpyrimidine‐5‐carbonitrile (PCNtTruX), were synthesized as sensitizers for TADF‐sensitized fluorescent organic light‐emitting diodes. The two tTCNTruX and PCNtTruX TADF emitters were designed to have Dexter energy transfer with blocking groups either in the donor or acceptor unit of the donor–acceptor‐type TADF sensitizer. The TADF materials showed small singlet–triplet energy splitting and a high reverse intersystem crossing (RISC) rate for effective sensitization of the fluorescent emission of the fluorescent emitter. tTCNTruX‐ and PCNtTruX‐sensitized fluorescent devices showed maximum external quantum efficiencies (EQEs) of 17.7 % and 11.5 % in the yellow and red devices, respectively, which were higher than those of TADF‐sensitized devices with the corresponding TADF sensitizer without a blocking group. Moreover, the device lifetime was also extended by employing the tTCNTruX and PCNtTruX sensitizers. This work demonstrated that the tTCNTruX and PCNtTruX sensitizers are effective to improve the maximum EQE and device lifetime of TADF‐sensitized fluorescent devices. [ABSTRACT FROM AUTHOR]

3‐Substituted quinoxalin‐2(1H)‐ones and various aryl‐substituted or tethered olefins underwent an enantioselective, inter‐ or intramolecular aza Paternò–Büchi reaction upon irradiation at λ=420 nm in the presence of a chiral sensitizer (10 mol %). For the intermolecular reaction with 1‐arylethenes as olefin components, the scope of the reaction was studied (14 examples, 50–99 % yield, 86–98 % ee). The absolute and relative configuration of the products were elucidated by single‐crystal X‐ray crystallography. The reaction is suggested to occur by triplet energy transfer in a hydrogen‐bonded 1:1 complex between the imine substrate and the catalyst. The intramolecular cycloaddition, consecutive reactions of the product azetidines, and an alternative reaction mode of quinoxalinones were investigated in preliminary experiments. [ABSTRACT FROM AUTHOR]

3‐Substituted quinoxalin‐2(1H)‐ones and various aryl‐substituted or tethered olefins underwent an enantioselective, inter‐ or intramolecular aza Paternò–Büchi reaction upon irradiation at λ=420 nm in the presence of a chiral sensitizer (10 mol %). For the intermolecular reaction with 1‐arylethenes as olefin components, the scope of the reaction was studied (14 examples, 50–99 % yield, 86–98 % ee). The absolute and relative configuration of the products were elucidated by single‐crystal X‐ray crystallography. The reaction is suggested to occur by triplet energy transfer in a hydrogen‐bonded 1:1 complex between the imine substrate and the catalyst. The intramolecular cycloaddition, consecutive reactions of the product azetidines, and an alternative reaction mode of quinoxalinones were investigated in preliminary experiments. [ABSTRACT FROM AUTHOR]

In the field of direct production of hydrogen from solar energy and water, photocatalytic methods hold great potential especially when metal‐free molecular components are preferred. In this work, we have developed a new class of calix[4]arene‐based molecular photosensitizers to be used as antenna systems in the photocatalytic production of hydrogen. The structure of the dyes has a typical donor‐π‐acceptor molecular architecture where a calix[4]arene scaffold is used as an embedded donor. The new materials have been fully characterized in their optical, electrochemical, and photocatalytic properties. The properties conferred by the calix[4]arene donor afforded twice larger performances compared to the corresponding linear system though showing similar quantitative optical properties. The new molecular design paves the way to a new strategy for photocatalytic hydrogen production where the calix[4]arene scaffold can afford more efficient systems and can offer the potential for host‐guest supramolecular effects. [ABSTRACT FROM AUTHOR]

Hyperfluorescence is emerging as a powerful strategy to develop optoelectronic devices with high‐color purity and enhanced stability. It requires appropriate integration of a sensitizer displaying efficient thermally activated delayed fluorescence (TADF) and an emitter displaying strong, narrow‐band fluorescence. Here, through a joint computational and experimental approach, an unprecedented, end‐to‐end systems level description of the electronic and optical processes that take place in a hyperfluorescent emissive layer composed of a TADF sensitizer, 2,5‐bis(2,6‐di(9H‐carbazol‐9‐yl)phenyl)‐1,3,4‐oxadiazole (4CzDPO), and a fluorescent emitter, 2,5,8,11‐tetra‐tert‐butylperylene (TBPe) is provided. The photophysical properties measurement of the emissive layer is combined with the computational determination of the electronic properties, film morphology, and excitation transfer phenomena. The Förster resonance energy transfer rates from 4CzDPO to TBPe are on the order of 1011 s−1, considerably higher than the radiative and nonradiative recombination rates for 4CzDPO. These features ensure nearly complete energy transfer to TBPe, leading to a five‐fold increase in the photoluminescence quantum yields in the 4CzDPO:TBPe system in comparison to neat films of 4CzDPO. This approach highlights the factors that can provide efficient energy transfer from TADF molecules to fluorescent emitters, suppress energy transfer among TADF molecules, and avoid the need for a host material within the emissive layer. [ABSTRACT FROM AUTHOR]

Organelle‐targeting photosensitizers have attracted increasing attention in the development of drugs for photodynamic therapy because they can efficiently induce cellular functional disorder upon light irradiation. In this work, we reported a ruthenium(II) complex bearing two lipophilic carbon chains which specifically binds to the cell membrane. Light irradiation on the complex‐treated cells caused an increase of intracellular reactive oxygen species. The photocytotoxicity of the complex toward HeLa cells were evaluated via the 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. A high dose (3 µm) of the complex induced apoptotic cell death by photogeneration of intracellular reactive oxygen species. A low dose (0.25 µm) of the complex did not cause noticeable cell death but increased the permeability of the cell membrane upon light irradiation. [ABSTRACT FROM AUTHOR]

Trisubstituted allenes with a 3‐(1′‐alkenylidene)‐pyrrolidin‐2‐one motif were successfully deracemized (13 examples, 86–98 % ee) employing visible light (λ=420 nm) and a chiral triplet sensitizer as the catalyst (2.5 mol %). The photocatalyst likely operates by selective recognition of one allene enantiomer via hydrogen bonds and by a triplet‐sensitized racemization process. Even a tetrasubstituted allene (45 % ee) and a seven‐membered 3‐(1′‐alkenylidene)‐azepan‐2‐one (62 % ee) could be enantiomerically enriched under the chosen conditions. It was shown that the axial chirality of the allenes can be converted into point chirality by a Diels–Alder (94–97 % ee) or a bromination reaction (91 % ee). Ring opening of the five‐membered pyrrolidin‐2‐one was achieved without significantly compromising the integrity of the chirality axis (92 % ee). [ABSTRACT FROM AUTHOR]

Trisubstituted allenes with a 3‐(1′‐alkenylidene)‐pyrrolidin‐2‐one motif were successfully deracemized (13 examples, 86–98 % ee) employing visible light (λ=420 nm) and a chiral triplet sensitizer as the catalyst (2.5 mol %). The photocatalyst likely operates by selective recognition of one allene enantiomer via hydrogen bonds and by a triplet‐sensitized racemization process. Even a tetrasubstituted allene (45 % ee) and a seven‐membered 3‐(1′‐alkenylidene)‐azepan‐2‐one (62 % ee) could be enantiomerically enriched under the chosen conditions. It was shown that the axial chirality of the allenes can be converted into point chirality by a Diels–Alder (94–97 % ee) or a bromination reaction (91 % ee). Ring opening of the five‐membered pyrrolidin‐2‐one was achieved without significantly compromising the integrity of the chirality axis (92 % ee). [ABSTRACT FROM AUTHOR]

Dye‐sensitized solar cells (DSSCs) based on CuII/I bipyridyl or phenanthroline complexes as redox shuttles have achieved very high open‐circuit voltages (VOC, more than 1 V). However, their short‐circuit photocurrent density (JSC) has remained modest. Increasing the JSC is expected to extend the spectral response of sensitizers to the red or NIR region while maintaining efficient electron injection in the mesoscopic TiO2 film and fast regeneration by the CuI complex. Herein, we report two new D‐A‐π‐A‐featured sensitizers termed HY63 and HY64, which employ benzothiadiazole (BT) or phenanthrene‐fused‐quinoxaline (PFQ), respectively, as the auxiliary electron‐withdrawing acceptor moiety. Despite their very similar energy levels and absorption onsets, HY64‐based DSSCs outperform their HY63 counterparts, achieving a power conversion efficiency (PCE) of 12.5 %. PFQ is superior to BT in reducing charge recombination resulting in the near‐quantitative collection of photogenerated charge carriers. [ABSTRACT FROM AUTHOR]

The dye‐sensitized solar cell (DSC) is a proven technology that operates efficiently under both sunlight and ambient dim light. However, because sunlight is significantly different from ambient dim light in terms of irradiance and emission spectrum, designing a single sensitizer that can perform equally efficiently under both conditions remains practically difficult. For the first time, panchromatic Ru(II) sensitizers bearing the tBu substituted 6‐quinolin‐8‐yl‐2,2′‐bipyridine anchor and 2,6‐bis(pyrazolyl)pyridine ancillary with peripheral CF3 and C3F7 substituents and central tBu substituent are synthesized to provide superior conversion efficiency. The quinolin‐8‐yl‐2,2′‐bipyridine anchor enhances the spectrum response from 550 to 700 nm, which is particularly important to fluorescent light spectrum. Furthermore, the introduction of bulky C3F7 and tBu groups effectively increase the steric hindrance that allows better dye uptake and suppresses interfacial recombination, both of which are important for light harvesting under dim light. The champion device in this study exhibits a remarkable power conversion efficiency of 31.82% under 6000 lux fluorescent light without the use of a cosensitizer. Meanwhile, the device also shows a high PCE of 10.37% under simulated 1 sun irradiation, making it the first ruthenium sensitizer suitable for both high and dim light applications under the same fabrication condition in DSC. [ABSTRACT FROM AUTHOR]

A general and straightforward way of preparing few‐nanometer‐sized well‐separated MAPbIxBr3−x (MA=methylammonium) perovskite photosensitizers on the surface of an approximately 1 μm thick mesoporous TiO2 photoanode was suggested through a two‐step sequential deposition of low‐concentrated lead halides (0.10–0.30 m PbI2 or PbBr2) and methylammonium iodide/bromide (MAI/MABr). When those nanoscale MAPbIxBr3−x perovskites were incorporated as a photosensitizer in typical solid‐state dye‐sensitized solar cells (ss‐DSSCs), it could be verified clearly by the capacitance analysis that nano‐particulate MAPbI3 perovskites play the same role as that of a typical dye sensitizer (MK‐2 molecule) although their size, composition, and structure are different. [ABSTRACT FROM AUTHOR]

A chiral phosphoric acid with a 2,2'‐binaphthol core was prepared that displays two thioxanthone moieties at the 3,3'‐position as light‐harvesting antennas. Despite its relatively low triplet energy, the phosphoric acid was found to be an efficient catalyst for the enantioselective intermolecular [2+2] photocycloaddition of β‐carboxyl‐substituted cyclic enones (e.r. up to 93:7). Binding of the carboxylic acid to the sensitizer is suggested by NMR studies and by DFT calculations to occur by means of two hydrogen bonds. The binding event not only enables an enantioface differentiation but also modulates the triplet energy of the substrates. [ABSTRACT FROM AUTHOR]