02528nas a2200253 4500008004100000022001400041245011700055210006900172260000800241300001400249490000800263520162300271653002301894653004201917653003001959653001801989100002402007700002702031700001702058700001702075700003002092700002702122856012502149 2024 eng d a0031-865500aFar-red active unsymmetrical squaraine dyes containing N-arylated indoline donors for dye sensitized solar cells0 aFarred active unsymmetrical squaraine dyes containing Narylated  cJUL a1116-11260 v1003 a

Squaraine dyes possess sharp far-red active transition with high extinction coefficient and form aggregates on TiO2 surface. Aggregation of dyes on TiO2 has been considered as a detrimental factor for DSSC device performance, which can be controlled by appending alkyl groups to the dye structures. Hence by integrating alkylated (alkyl groups with both in-plane and out-of-plane) aryl group with indoline moiety to make it compatible with other electrolytes and for controlling the dye-aggregation, a series of squaraine acceptor-based dyes SQA4-6 have been designed and synthesized. SQA4-6 dyes showed absorption between 642 and 653 nm (lambda max), photophysical and electrochemical studies indicated that the HOMO energy levels of this sets of dyes are well aligned with the potentials of I-/I3-\$\$ {\textbackslashmathrm{I}}_3<\^>{-} \$\$ and [Co(bpy)3]2+/3+ redox shuttles for better dye regeneration process. DSSC device efficiency of 3% has been achieved for SQA5 dye with iodolyte (I-/I3-\$\$ {\textbackslashmathrm{I}}_3<\^>{-} \$\$) electrolyte in the presence of 0.3 mM of chenodeoxycholic acid (CDCA). The IPCE profile of DSSC device fabricated with SQA4-6 dyes indicated the contribution of aggregated structures for the photocurrent generation. Dye-sensitized solar cell (DSSC) device efficiency of 3% (Jsc 5.72 mA cm-2, Voc 662 mV and ff 79%) has been achieved for an unsymmetrical squaraine dye, SQA5 with iodolyte electrolyte and the incident photon to current efficiency (IPCE) profile indicates the contribution of aggregated structures for the photocurrent generation.*image

10aaggregation of dye10aarylation on N-atom of indoline donor10adye-sensitized solar cell10asquaraine dye1 aJadhav, Avinash, P.1 aSingh, Ambarish, Kumar1 aPandya, Rinu1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aJayaraj, Nithyanandhan uhttps://library.ncl.res.in/content/far-red-active-unsymmetrical-squaraine-dyes-containing-n-arylated-indoline-donors-dye02521nas a2200217 4500008004100000022001400041245016800055210006900223260000900292300001400301490000700315520171300322100002202035700001502057700002402072700001702096700001702113700002402130700002402154856012502178 2024 eng d a2050-752600aUnravelling polymorphism-driven luminescence in GFP chromophore analogues: insights into the phase transition and morphology-dependent optical waveguide properties0 aUnravelling polymorphismdriven luminescence in GFP chromophore a cJUN  a8368-83790 v123 a

The advent of multi-emission organic solid-state materials in response to external stimuli has sparked the scientific community due to their potential application in developing sophisticated optoelectronic sensors and bioanalytical tools. This article presents green fluorescent protein chromophore (GFPc) analogue-based polymorphs exhibiting significantly different emissions due to various noncovalent interactions in the supramolecular environment and conformational alterations in the crystalline state. In both compounds (A and B), the polymorphs undergo monotropic thermal phase transitions that are characterized by DSC, HSM, and VT-PXRD techniques. The distinct fluorescent emission characteristics of these polymorphs demonstrated morphology-related optical waveguiding features. Specifically, the plate-type Form A1 emitted light with a 2D blue hue, while the needle-type Form A2 emitted light with a yellowish-green colour. Additionally, the impressive waveguiding capabilities of Form B1 were explored in both straight and singly/doubly bending configurations to facilitate fluorescence propagation. Consequently, there is significant interest in developing organic materials based on GFP chromophores, which exhibit low emission in solution but display multi-fluorescent emission in the solid state. These materials are promising for applications such as optoelectronic devices, security tags, live cell imaging, and fluorescent inks. Polymorphs of GFPc analogs A and B display differences in their optical waveguiding properties in 1D and 2D depending on the crystal shapes. Furthermore, Form B1 demonstrates efficient optical waveguiding capabilities even when the crystal is bent.

1 aDabke, Niteen, B.1 aRaut, Yash1 aMali, Bhupendra, P.1 aPandya, Rinu1 aVanka, Kumar1 aManoj, Kochunnoonny1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/unravelling-polymorphism-driven-luminescence-gfp-chromophore-analogues-insights-phase00891nas a2200265 4500008004100000022001400041245011500055210007000170260000900240300001600249490000700265653001500272653001700287653001500304653001500319100002500334700001700359700001900376700002100395700001500416700002000431700002000451700001700471856013700488 2024 eng d a1359-734500aUnravelling the prebiotic origins of the simplest α-ketoacids in cometary ices: a computational investigation0 aUnravelling the prebiotic origins of the simplest αketoacids in  cOCT  a11283-112860 v6010aGLYOXYLATE10aHydrocarbons10aMetabolism10aPrecursors1 aDash, Soumya, Ranjan1 aPandya, Rinu1 aSingh, Geetika1 aSharma, Himanshu1 aDas, Tamal1 aHaldar, Hritwik1 aHotha, Srinivas1 aVanka, Kumar uhttps://library.ncl.res.in/content/unravelling-prebiotic-origins-simplest-%CE%B1-ketoacids-cometary-ices-computational-investigation02396nas a2200205 4500008004100000022001400041245011500055210006900170260000800239300001400247490000700261520167200268100001801940700002201958700001701980700001701997700002202014700002402036856013002060 2025 eng d a1528-748300aCocrystals of the green fluorescence protein chromophore analogue: coformer-induced switch between AIE and ACQ0 aCocrystals of the green fluorescence protein chromophore analogu cSEP a7473-74880 v253 a

Fluorescent organic solids hold great potential for advancing photonics applications. However, tuning their solid-state photoluminescent emissions remains a significant challenge. In this study, we report the synthesis and characterization of five cocrystals (two cocrystal polymorphs) derived from a pristine imidazolinone derivative (A) and the various coformer molecules, namely 1,2,4,5-tetrafluoro-3,6-diiodobenzene, 1,2,4,5-tetrafluoro-3,6-dibromobenzene, perfluoronaphthalene, and 3,4,5-trifluorobenzoic acid. The structural and optical properties of these cocrystals were examined by using single-crystal X-ray diffraction, absorption spectroscopy, photoluminescence spectroscopy, and photoluminescence decay spectroscopy. Cocrystals I, II, and III are isomorphous pairs and exhibit three-dimensional isostructurality, where the coformer molecules bridge adjacent helices of compound A, leading to aggregation-induced emission. In contrast, the cocrystal polymorphs IVA and IVB developed using coformer 3,4,5-trifluorobenzoic acid form two-dimensional sheet-like structures mediated by pi-stacking interactions between the coformers and molecule A, with interplanar distances ranging from 3.2 to 3.5 & Aring;. These stronger pi-pi interactions promote nonradiative decay pathways, resulting in reduced or quenched fluorescence and an aggregation-caused quenching effect. To gain further insights into their electronic properties, theoretical analysis including frontier molecular orbitals, time-dependent density functional theory, Hirshfeld surface analysis, molecular electrostatic potential, and noncovalent interaction plots were performed.

1 aSuresh, Sneha1 aDabke, Niteen, B.1 aPandya, Rinu1 aVanka, Kumar1 aDutta, Madhusudan1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/cocrystals-green-fluorescence-protein-chromophore-analogue-coformer-induced-switch-between02640nas a2200289 4500008004100000022001400041245015900055210006900214260000800283300001100291490000800302520162200310653002401932653002101956653002401977653003102001653002502032653001902057653001802076100002602094700001602120700001702136700001702153700003002170700002702200856012302227 2025 eng d a1010-603000aDouble anchoring squaraine dye with triazatruxene amine donor for dye-sensitized solar cells: sequential cosensitization for panchromatic light-harvesting0 aDouble anchoring squaraine dye with triazatruxene amine donor fo cMAY a1162290 v4623 a

Dyes are firmly bound to a semiconducting TiO2 film using carboxylic acid anchoring groups for an efficient electron transfer from the excited state of dye to the conduction band (CB) of TiO2. Strong dye binding can be accomplished with multi-anchoring dye designs to improve photophysical characteristics, including high extinction coefficients, panchromatic absorption, post-sensitization modifications, and dark current suppression, besides enhancing the stability of the dye-TiO2 interface. Herein, a novel KV2D dye with double squaraine acceptor and double carboxylic acid anchoring groups is designed to achieve a high extinction coefficient (epsilon, 3.57 x 105M-1cm-1) and robust binding to the TiO2 film for an effective electron transfer. We systematically changed the amount of coadsorbent chenodeoxycholic acid (CDCA) to control the aggregation of dyes on the TiO2 surface that improves the power conversion efficiency (PCE, eta) for the devices based on the doubleanchoring KV2D. Out of these devices, KV2D: CDCA (1:10) based cell exhibited the best PCE of 5.26% with VOC of 754 mV, JSC of 10.41 mA/cm2, and ff of 67%. The sequential cosensitization studies were carried out with a far-red active dye to find the effect of the strong binding of the sensitizer to the TiO2 film. Interestingly, when di-anchoring, KV2D was sensitized first for 12 h and then sequentially cosensitized with far-red absorbing SQS4 for 5 h to achieve a PCE of 5.0% with VOC of 697 mV, JSC of 10.23 mA/cm2, and ff of 70% with panchromatic spectral response in IPCE upto 730 nm giving higher photocurrent generation.

10aaggregation of dyes10aBulky donor unit10aDouble acceptor dye10aDye-sensitized solar cells10aself-assembly of dye10asquaraine dyes10atriazatruxene1 aIngole, Kiran, Balaso1 aSiby, Jesna1 aPandya, Rinu1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/double-anchoring-squaraine-dye-triazatruxene-amine-donor-dye-sensitized-solar-cells02455nas a2200241 4500008004100000022001400041245012100055210006900176260000800245300001400253490000700267520164400274100001901918700001801937700001701955700001601972700001701988700001902005700001702024700002002041700002102061856013102082 2025 eng d a2040-336400aInvestigating the visible range photoresponse of an organic single-crystal analogue of the green fluorescent protein0 aInvestigating the visible range photoresponse of an organic sing cAPR a8614-86230 v173 a

The growing demand for lightweight, flexible, semi-transparent and low-cost photodetectors (PDs) in wearable electronics and optical communication systems has prompted studies to investigate organic materials as feasible alternatives to conventional inorganic PDs. However, modern organic PDs often face responsivity, detectivity, and photoresponse speed limitations, particularly in the visible range. Here, we present the photoresponse of an organic single-crystal analogue of the green fluorescent protein (GFP) chromophore photodetector, fabricated on a silicon nitride substrate. A significant increase in photocurrent was detected upon illumination with visible wavelengths (532 nm, 630 nm, and halogen light). A remarkably consistent and repeatable photoresponse was obtained during the ON and OFF illumination cycles. The device showed the dependence of photocurrent on the applied bias voltages. The measured photocurrent, responsivity, detectivity, rise time, decay time, noise equivalent power and external quantum efficiency are studied for different wavelengths. Strikingly, the fabricated device demonstrates excellent performance in the visible region compared to several conventional organic and inorganic PDs. The observed responsivity and detectivity values for the device are 98 mA W-1 and 7.94 x 108 Jones, respectively. Furthermore, the device also exhibits rapid photoresponse dynamics with a rise time of 180 ms and a decay time of 152 ms. The excellent photodetection features indicate that the single crystal GFP could serve as a versatile broadband material for future applications in optoelectronics.

1 aVirole, Vishal1 aDabke, Niteen1 aVerma, Sahil1 aKumar, Ajay1 aPandya, Rinu1 aHusale, Sudhir1 aVanka, Kumar1 aGonnade, Rajesh1 aKanawade, Rajesh uhttps://library.ncl.res.in/content/investigating-visible-range-photoresponse-organic-single-crystal-analogue-green-fluorescent01554nas a2200205 4500008004100000022001400041245008300055210006900138260000800207300001600215490000700231520088700238100002701125700002001152700001701172700001701189700001901206700001901225856010401244 2025 eng d a1477-922600aManganese(i)-catalyzed dehydrogenative borylation of terminal alkynes0 aManganesescisccatalyzed dehydrogenative borylation of terminal a cJUL a10426-104320 v543 a

Compounds containing carbon-boron bonds serve as valuable intermediates for constructing more complex molecules by transforming these bonds into other carbon-element bonds. The catalytic dehydrogenative borylation of carbon-hydrogen bonds using HBpin presents an appealing method for synthesizing carbon-boron bonds. While this approach has been extensively explored with noble metals for various types of carbon-hydrogen bonds, its application with manganese-based catalysts remains rare. This study explores a dehydrogenative borylation process employing an Earth-abundant transition metal catalyst, FcbpyMn(CO)3Br (Mn(i)), in combination with HBpin under mild conditions. Arylalkynes featuring electron-withdrawing, electron-donating, and heteroaryl substituents yielded good to excellent results. Thorough DFT calculations were performed to understand the mechanism.

1 aGhanwat, Pratiksha, B.1 aBora, Debashree1 aPandya, Rinu1 aVanka, Kumar1 aSaha, Biswajit1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/manganesei-catalyzed-dehydrogenative-borylation-terminal-alkynes01579nas a2200253 4500008004100000022001400041245011600055210006900171260000800240490000700248520072200255653001300977653002900990653001601019653002901035653002001064653002601084100001801110700002001128700001701148700001701165700002001182856012301202 2025 eng d a0947-653900aUnlocking thermodynamic enolate for kinetically controlled desymmetrizing vinylogous (4+1) carbospiroannulation0 aUnlocking thermodynamic enolate for kinetically controlled desym cMAY0 v313 a

An unprecedented thermodynamically unfavorable (4+1) deysmmetrizing spiroannulation through a thermodynamic enolate intermediate, enabling a single-step synthesis of ubiquitous scaffolds such as all-carbon chiral spirocycles, is disclosed. In this spiroannulation, we present a vinylogous organocatalytic enantioselective desymmetrizing (4+1) cycloaddition approach involving alkylidene malononitrile and cyclopent-1,3-dienone. This carbospiroannulation method produces functionally enriched spiro[4,4]nonane structures with three stereocenters, has presented good-to-high yields and enantiomeric ratios. Detailed DFT calculations reveal an intriguing reaction mechanism, which validates our observations.

10a3-diones10aalkylidene malononitrile10acyclopent-110aquaternary stereocenters10aspiro compounds10athermodynamic enolate1 aSingh, Sanjay1 aSingh, Abhijeet1 aPandya, Rinu1 aVanka, Kumar1 aSingh, Ravi, P. uhttps://library.ncl.res.in/content/unlocking-thermodynamic-enolate-kinetically-controlled-desymmetrizing-vinylogous-4103762nas a2200265 4500008004100000022001400041245015300055210007000208260000800278300001600286490000600302520279600308653002003104653002003124653003103144653003003175653002803205100002403233700001603257700001703273700001703290700003003307700002703337856013203364 2025 eng d a2574-096200aVisible-light active π-extended unsymmetrical squaraine dyes for dye-sensitized solar cells: steric effects for controlling the aggregation of dyes0 aVisiblelight active πextended unsymmetrical squaraine dyes for d cOCT a15459-154700 v83 a

The dye-anchored TiO2 photoanode plays a vital role in the light harvesting and charge separation processes in dye-sensitized solar cells. Aggregation of dyes (H- and J-type) on the TiO2 surface is a facile process due to the presence of a periodical dye anchoring sites on the exposed facet of titania, and such self-assembled dye structures help broadening the absorption profile. However, photocurrent generation from such aggregated structure is a challenging task in dye-sensitized solar cell devices. Hence, controlling the dye aggregation on the TiO2 surface is an important aspect. Controlling the aggregation of dyes by which (i) an enhanced photocurrent generation (J SC) and (ii) enhanced V OC can be achieved by including the steric factors to the dye design principles, the steric factor in the sensitizer may help passivate the TiO2 surface to avoid the charge recombination process between electrons present in TiO2 and the oxidized electrolyte. On the other hand, extension of pi-conjugation in a sensitizer helps enhance the light absorption in the visible region besides modulating the HOMO and LUMO energy levels. Hence, synergizing both pi-extensions along with features that control the dye aggregation has been considered in designing visible active squaraine dyes. A thiophene pi-spacer was inserted in between a visible-light active unsymmetrical squaraine unit and a cyanoacetic acid acceptor unit to provide the AJ1 and AJ2 dyes. Though both the dye molecules possess a similar pi-framework, the AJ2 dye was functionalized with both in-plane and out-of-plane alkyl groups to decrease the aggregation of dyes on the TiO2 surface compared to AJ1. The AJ1 and AJ2 dyes absorbed at 560 nm with shoulder peaks appeared at 528 nm, which can be assigned to vibronic progression (1082 cm-1), and additional characteristic peaks of thiophene appeared at 392 nm with the molar extinction coefficient of 1.16-1.19 x 105 M-1 cm-1 in CH3CN. The LUMO and HOMO energy levels are well aligned with the conduction band of TiO2 and the redox potential of iodolyte (I-/I3 -) electrolyte with sufficient overpotentials for charge injection and dye regeneration processes, respectively. The highest DSSC device efficiency of 7.37% (J SC 14.44 mA/cm2, V OC 0.771 V, ff 67.1%) was achieved for the AJ2 dye with iodolyte (I-/I3 -) electrolyte in the presence of 2 equiv of optically transparent coadsorbent chenodeoxycholic acid (CDCA), which showed a good IPCE response in between 400 and 700 nm. Further, cosensitization of visible-light active AJ1, AJ2, and SQA10 dyes with a complementary far-red active SQS4 dyes showed the device efficiencies of 5.53% (AJ1:SQS4:CDCA), 7.14% (AJ2:SQS4:CDCA), and 7.18% (SQA10:SQS4:CDCA) with a good IPCE response in the 400-720 nm region.

10acosensitization10aDye aggregation10aDye-sensitized solar cells10api-extended squaraine dye10avisible-lightactivedyes1 aJadhav, Avinash, P.1 aSiby, Jesna1 aPandya, Rinu1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/visible-light-active-%CF%80-extended-unsymmetrical-squaraine-dyes-dye-sensitized-solar-cells02224nas a2200253 4500008004100000022001400041245018000055210006900235260000800304490000700312520127300319653002101592653003101613653002501644653001901669653001801688100002601706700001601732700001701748700001701765700003001782700002701812856013101839 2026 eng d a1861-472800aAuxiliary triazatruxene donor-based squaraine dyes for dye-sensitized solar cells: cis- and trans- configuration of dyes for modulating photophysical and electronic properties0 aAuxiliary triazatruxene donorbased squaraine dyes for dyesensiti cJAN0 v213 a

In DSSCs, dye regeneration efficiency and dye aggregation on the TiO2 surface can be modulated by using bulky aromatic donors wrapped with alkyl groups. Introduction of rigid aromatic rings around the donor unit of a dye will directly impact the driving force for electron injection and dye regeneration of a dye. In this work, we designed and synthesized KNS dyes with an auxiliary TAT donor integrated with a visible active squaraine dye. Here, octupolar-structured auxiliary TAT wrapped with alkyl groups is used as a strong donor and shelter to reduce the dye aggregation and charge recombination process. Further, to improve the light-harvesting efficiency and incident photon-to-current conversion efficiency of DSSC devices fabricated with KNS dyes, the central squaric acid unit has been modified by appending the electron-withdrawing dicyano group at the central squaric unit, and the trans-configured KNS1 dye was converted to cis-configured KNS2 dye. The power conversion efficiency of devices based on the KNS dyes was studied with and without 3 equivalents of CDCA by using the I-/I3 - electrolyte. Out of these devices, the KNS1: CDCA (1:3) based cell exhibited the best PCE of 6.25% with V OC of 793 mV, J SC of 11.08 mA cm-2, and ff of 71%.

10aBulky donor unit10aDye-sensitized solar cells10aself-assembly of dye10asquaraine dyes10atriazatruxene1 aIngole, Kiran, Balaso1 aSiby, Jesna1 aPandya, Rinu1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/auxiliary-triazatruxene-donor-based-squaraine-dyes-dye-sensitized-solar-cells-cis-and-trans02813nas a2200301 4500008004100000245016300041210006900204260000800273300001200281490000600293520178700299653002402086653002102110653002102131653002102152653002402173100002302197700001802220700001902238700001702257700001702274700001602291700001902307700001702326700001802343700002102361856012902382 2026 eng d00aPhotoluminescence decay lifetime study of hydrothermally synthesized highly porous ruthenium-silica composite for optical dissolved oxygen sensing application0 aPhotoluminescence decay lifetime study of hydrothermally synthes cJAN a937-9490 v93 a

Pore size and surface area of photoluminescence (PL)-based transition metal composites play crucial roles in facilitating oxygen diffusion, thereby enhancing the response and sensitivity of optical dissolved oxygen (DO) sensors. In this study, we successfully applied the hydrothermal method to synthesize a porous ruthenium composite embedded in a silica matrix, demonstrating its effectiveness for optical DO sensing applications. The ruthenium-silica (Ru-Si) composites were synthesized using Ru(bpy)3 2+ and tetraethyl orthosilicate (TEOS) as precursors, with reaction temperatures ranging from 120 degrees C to 200 degrees C over a fixed duration of 4 h. The structural, morphological, and compositional characterization techniques confirmed the successful synthesis and evaluated the porosity, surface features, and chemical structure of the resulting composites. The optimized Ru-Si composite exhibited the highest porosity, characterized by a specific surface area of 996.78 m2 g- 1, and exhibited the highest decay lifetime of 8.14 mu s in deionized (DI) water, compared to other composites. Importantly, we demonstrate an excellent linear response of the synthesized Ru-Si composite to DO concentrations ranging from 2.58 to 11.16 mg L-1, with a Stern-Volmer constant of 0.12. Furthermore, a density functional theory study was conducted to investigate the electronic transitions and to elucidate the oxygen quenching mechanism of the excited Ru composite with molecular oxygen. The calculated photophysical parameters of the composite show good agreement with the experimental results. Preliminary results suggest that the synthesized Ru-Si with high pore size and surface area could be an efficient and effective composite for use in DO sensing applications.

10aHydrothermal method10aopticalDO sensor10aoxygen quenching10aphotoluminescent10aruthenium composite1 aHattale, Gangadhar1 aKadam, Rutuja1 aVirole, Vishal1 aPandya, Rinu1 aPaul, Aditya1 aKumar, Ajay1 aShevate, Rahul1 aVanka, Kumar1 aSaha, Avishek1 aKanawade, Rajesh uhttps://library.ncl.res.in/content/photoluminescence-decay-lifetime-study-hydrothermally-synthesized-highly-porous-ruthenium