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A straightforward strategy for the synthesis of pharmaceutically active 2‐aminobenzoxazoles and 2‐aminobenzothiazoles is described by using 2‐aminophenols, 2‐aminothiophenols, and functionalized phenylisothiocyanates as the model substrates. The developed method proceeds through the HFIP‐promoted cyclodesulfurization process which allows for the efficient synthesis of these scaffolds at 60 °C of reaction temperature without the addition of a transition metal‐catalyst or hazardous solvents with excellent yields (up to 92 %) of product formation. This process involves HFIP‐mediated hydrogen bonding interactions with the hydroxyl and thiol moieties, leading to bond breaking and formation during the reaction, resulting in the compounds of interest and the in situ release of H2S gas. [ABSTRACT FROM AUTHOR]

The increasing global demand for energy and growing environmental concerns emphasize the crucial role of solar energy as a sustainable and nondepletable resource. Solar cells, particularly dye‐sensitized solar cells (DSSCs), have gained prominence due to their efficient conversion of solar power, ecofriendly manufacturing processes, and noteworthy stability. Current research in sustainable energy focuses on transitioning from metal‐based to metal‐free organic materials. Tandem solar cells, combining n‐type and p‐type semiconductors sensitized with diverse photoactive dyes, show potential to surpass thermodynamic limits in photon conversion efficiency. Notably, the exploration of n‐type DSSCs as photoanodes in tandem architectures is promising. However, the absence of efficient p‐type photoactive cathodes remains a significant obstacle. Global research efforts are dedicated to addressing charge recombination issues in NiO‐based devices to enhance the efficiency of p‐type DSSCs. The success of any DSSC hinges on the selection of dyes/sensitizers with suitable anchoring groups, wide absorption in the visible–NIR region, and a high extinction coefficient. This article comprehensively reviews advancements in developing highly efficient p‐type sensitizers, emphasizing their pivotal role in unlocking the full potential of tandem solar cells. [ABSTRACT FROM AUTHOR]

A combination of reagents using I2 and DMSO has been established for the selective transformation of unactivated alkenes into iodohydrins and β‐iodoethers. The developed approach was served by the dual roles of DMSO as an oxidant as well as a hydroxylating agent under different solvent systems at 85 °C. The developed method holds an operational simplicity and is consistent with wide range of substituted alkenes to deliver iodohydrins and β‐iodoethers in yields up to 86 %. The formation of iodohydrins are selective in MeCN as solvent and the course of the reaction was examined by GC‐MS studies and DFT method. [ABSTRACT FROM AUTHOR]

Development of new, cost effective, stable heterogeneous catalyst for the organic transformations is an important thematic area of research. Present work describes the development of new Pd@rGO−CuFe2O4 catalyst and demonstrates its effectiveness for Suzuki‐Miyaura type coupling reactions. The additional advantage of this reaction is its feasibility using biomass‐derived solvent like γ‐Valerolactone (GVL) in aqueous media. The catalyst is prepared hydrothermally and characterized using XRD, FESEM, EDX, and XPS analysis. The catalyst exhibits excellent activity and recyclability (up to six times) in the C−C coupling reaction to deliver the corresponding biaryl molecules in yields up to 90 %. High efficiency for the conversion of nitriles to amides is also revealed by the prepared catalyst. [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]

The present work describes the effect of structural modification of carbazole‐based photosensitizers carrying carboxylic acid as a common anchoring functionality, on the photovoltaic parameters of newly fabricated DSSCs. In this study, we have selected our previously reported three carbazole‐based derivatives, viz. S1‐3 having different structural designs, that is, D‐π‐A (S1), D‐D‐π‐A (S2), and A‐π‐D‐π‐A (S3) with different donor units and π‐spacers, but an identical cyanoacetic acid anchoring unit. We have evaluated their optical, electrochemical, and photovoltaic behaviors in order to explore their structure‐property relationships. Also, the theoretical investigations were performed to obtain a deeper understanding of their HOMO‐LUMO levels, charge distribution in FMOs, directional flow of electrons within the push‐pull type sensitizers, and optical behavior. Finally, the DSSCs were constructed by employing these dyes as sensitizers without any co‐absorbents and the performance of the devices was evaluated by using illuminated current‐voltage characteristics. Among the tested dyes, di‐anchoring S3 exhibited improved PCE of 3.77 % due to its strong adsorption on the TiO2 surface that resulted in superior VOC of the cell. While the S2 containing electron‐releasing anisole as an auxiliary donor exhibited better JSC value leading to the optimum PCE of 3.73 % which is comparable to that of S3. Obviously, these results validate the role of the π‐spacer and additional donor of the sensitizers on the overall performance of the DSSCs. [ABSTRACT FROM AUTHOR]

Herein, we report the development of two new low-cost 9-(2-ethylhexyl)-9Hcarbazoles carrying the mono/dimethoxyphenyl substituted cyanovinylene units symmetrically at 3- and 6-positions of the carbazole core (CZ1-2), as potential hole-transporting materials (HTMs) for perovskite solar cell (PSC) application. The current work highlights their structural, photophysical, electrochemical, theoretical, and photoelectrochemical studies, including evaluation of their structure-property relationships. Evidently, the optical studies showcased their excellent fluorescence ability due to their push-pull natured structure; their λabs and λemi values were found to be in the order of 410-430 nm and 530-560 nm, respectively, with a bandgap in the range of 2.5-2.6 eV. Further, their theoretical studies, performed by using the DFT simulations clearly revealed in-depth information on their molecular geometries, FMO, and electronic properties. Finally, new PSCs were fabricated successfully by employing CZ1-2 as HTMs to evaluate their photovoltaic performances. Their results indicated that the device with CZ1 displayed enhanced PCE of 2.55% (JSC = 7.85 mA/cm2, VOC = 0.79 V and FF = 40%) than the cell with CZ2 (PCE = 1.71%, JSC = 8.15 mA/cm2, VOC = 0.4 V, FF = 49%) and the obtained data are well comparable with reference, Sipro- OMeTAD (PCE = 4.76%, JSC = 12.27 mA/cm2, VOC = 0.84 V, FF = 45%). Conclusively, the study furnishes a deeper understanding of the intricacies involved in the structuralmodification of in low-costHTM in achieving an enhanced performance of the devices. [ABSTRACT FROM AUTHOR]

Developing effective and low‐cost organic hole‐transporting materials (HTMs) is crucial for the construction of high‐performance perovskite solar cells (PSCs) and to promote their production in commercial ventures. In this context, we herein report the molecular design, synthesis and characterization of two novel D‐A‐D‐A‐D architectured 9‐(2‐ethylhexyl)‐9H‐carbazoles, connecting the mono/dimethoxyphenyl substituted cyanovinylene sidearms symmetrically at 3rd and 6th positions of the carbazole heterocycle (CZ1‐2), as potential hole‐transporting materials (HTMs). The current work highlights their structural, photophysical, thermal, electrochemical and theoretical investigations, including their structure‐property correlation studies. Evidently, the optical studies showcased their excellent fluorescence ability due to their push–pull natured structure with extended π‐conjugation. Further, in‐depth solvatochromic studies demonstrated their intramolecular charge‐transfer (ICT)‐dominated optoelectronic behavior, supported by various correlation studies. Also, the optical results revealed that CZ1 and CZ2 display λabs and λemi in the order of 410–430 nm and 530–560 nm, respectively, with a bandgap in the range of 2.5–2.6 eV. Finally, their quantum chemical simulations have provided an insight into the predictions of their structural, molecular, electronic and optical parameters. Conclusively, the study furnishes a deeper understanding of the intricacies involved in the structural modification of carbazole‐based HTMs for achieving better performance. [ABSTRACT FROM AUTHOR]

Herein, we report the design and synthesis of four new thiophene-bridged D–π–A configured organic dyes T1–4 comprising different donors, π-spacers and anchoring units, as potential sensitizers and co-sensitizers for DSSCs. The current work also highlights their structural, photophysical, thermal, electrochemical, theoretical, and photoelectrochemical studies, including evaluation of their structure–property relationships. The optical results revealed that the dyes T1–4 display λabs and λemi in the range of 402–461 nm and 556–575 nm, respectively, with a bandgap in the order of 2.31–2.58 eV. Furthermore, the results showed that the dyes possess all the pre-requisites to act as sensitizers/co-sensitizers. Among the tested dyes, the device based on sensitizer T2 achieved the highest PCE compared to the other three dyes, under the standard conditions. Furthermore, their co-sensitized devices were fabricated by co-adsorbing them with the well-known Ru-based MH-12 sensitizer and interestingly the co-sensitizer T3 carrying an alkoxy group and a barbituric acid anchor displayed the highest PCE of 8.79%, which is much higher than that of MH-12 alone (8.18%). Conclusively, the study furnishes a deeper understanding of the intricacies involved in the structural modification of sensitizers/co-sensitizers in achieving an enhanced performance of the devices. [ABSTRACT FROM AUTHOR]

The main objective of our present investigation includes the design synthesis and characterization of two novel D-π-A configured carbazole based dyes C1-2, carrying two different anchors and the same donor system. In the new design, a simple O-alkylated phenyl group as a donor scaffold, cyanovinylene and thiophene group serve as a π-spacer, while cyanoacetic acid, barbituric acid units function as electron acceptor/ anchoring units. The newly synthesized compounds were characterized by FTIR, NMR spectroscopic techniques including the elemental analysis. Further, their optical properties were investigated by using UV-visible, fluorescence spectrophotometer. In addition, the Density functional theory (DFT) calculations were performed to get their electron distribution in FMO levels. In order to investigate their photovoltaic characteristics, the synthesized dyes were employed as sensitizers towards the fabrication of DSSC's. The device fabricated with dye C1 displayed better PCE of 1.2 % with JSC of 3.64 mA·cm-2, VOC of 0.50 V and FF of 65 % than other dye C2. These experimental results provide a better understanding and deeper insight into the intricacies involved in the design of superior sensitizers to further improve the performance of DSSCs. [ABSTRACT FROM AUTHOR]