02015nas a2200205 4500008004100000022001400041245010700055210006900162260000900231300001600240490000700256520126800263100002301531700004001554700001801594700001801612700001801630700003001648856013101678 2023 eng d a1144-054600aDonor-acceptor-based two-dimensional polymer as a supercapacitor electrode with long cycling stability0 aDonoracceptorbased twodimensional polymer as a supercapacitor el cOCT  a18049-180540 v473 a

The high demand for energy and energy-storage devices urged organic 2D polymers as a potential candidate in this area. One of the major attractions of 2D polymers in electrochemical applications is their long cycling stability due to their rigid and porous structure. Herein, we developed a 2D polymer comprised of donor-acceptor units exhibiting reasonably good performance as a supercapacitor. The 2D polymer displayed a maximum specific capacitance of 218 F g-1 at a current rate of 0.1 A g-1, a higher power density of 4648.35 W kg-1, and an energy density of 7.05 W h kg-1. In a cycling stability test, it demonstrated a capacitance retention of 70% over 10 000 continuous charge-discharge cycles at a current rate of 2.5 A g-1. Such long cycling stability was attributed to the donor-acceptor units and the crystalline nature of the polymer. The sensible selection of the building blocks of the 2D polymers is crucial for the performance and hence provides scope for improvement. An organic donor-acceptor-based 2D polymer, a promising candidate for energy storage devices, displays a specific capacitance of 218 F g-1, a power density of 4648.35 W kg-1, an energy density of 7.05 W h kg-1, and a capacitance retention of 70% over 10 000 cycles.

1 aBhagyasree, T., M.1 aPuthiyaveetil, Priyanka, Pandinhare1 aKumar, Viksit1 aAsokan, Kiran1 aSreekumar, K.1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/donor-acceptor-based-two-dimensional-polymer-supercapacitor-electrode-long-cycling-stability02617nas a2200253 4500008004100000022001400041245008400055210007000139260000800209490000700217520178600224653001202010653001302022653001902035653001702054653003102071100001802102700002502120700002402145700002002169700003002189700003002219856011402249 2023 eng d a1433-785100aIsomer effect on energy storage of π-extended S-shaped double[6]heterohelicene0 aIsomer effect on energy storage of πextended Sshaped double6hete cNOV0 v623 a

Recently, chiral and nonplanar cutouts of graphene have been the favorites due to their unique optical, electronic, and redox properties and high solubility compared with their planar counterparts. Despite the remarkable progress in helicenes, pi-extended heterohelicenes have not been widely explored. As an anode in a lithium-ion battery, the racemic mixture of pi-extended double heterohelical nanographene containing thienothiophene core exhibited a high lithium storage capability, attaining a specific capacity of 424 mAh g-1 at 0.1 A g-1 with excellent rate capability and superior long-term cycling performance over 6000 cycles with negligible fade. As a first report, the pi-extended helicene isomer (PP and MM), with the more interlayer distance that helps faster diffusion of ions, has exhibited a high capacity of 300 mAh g-1 at 2 A g-1 with long-term cycling performance over 1500 cycles compared to the less performing MP and PM isomer and racemic mixture (150 mAh g-1 at 2 A g-1). As supported by single-crystal X-ray analysis, a unique molecular design of nanographenes with a fixed (helical) molecular geometry, avoiding restacking of the layers, renders better performance as an anode in lithium-ion batteries. Interestingly, the recycled nanographene anode material displayed comparable performance. A pi-extended double heterohelical nanographene of thienothiophene core fused with two hexabenzocoronene units exhibits excellent performance as an anode in a lithium-ion battery. The isomer (PP and MM) with more interlayer distance exhibited a high lithium storage capability compared to the other isomer and racemic mixture. Helical nanographene anodes display excellent rate capability, superior long-term cycling performance, and recyclability.image

10aBattery10agraphene10aLi-ion battery10ananographene10aOrganic Electrode Material1 aKumar, Viksit1 aBharathkumar, H., J.1 aDongre, Sangram, D.1 aGonnade, Rajesh1 aKrishnamoorthy, Kothandam1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/isomer-effect-energy-storage-%CF%80-extended-s-shaped-double6heterohelicene02176nas a2200253 4500008004100000022001400041245011800055210006900173260000800242490000700250520127800257653002001535653001901555653003301574653001401607653001601621100003301637700002901670700002601699700001801725700002201743700003001765856012701795 2023 eng d a1433-785100aPolymerizable solvent-free organic liquids: a new approach for large area flexible and foldable luminescent films0 aPolymerizable solventfree organic liquids a new approach for lar cAUG0 v623 a

The high demand for light-emitting and display devices made luminescent organic materials as attractive candidates. Solvent-free organic liquids are one of the promising emitters among them due to the salient features. However, the inherent limitations of forming sticky and noncurable surfaces must be addressed to become an alternate emitter for large-area device applications. Herein, we functionalized solvent-free organic liquids having monomeric emission in bulk with polymerizable groups to improve the processability. The polymerizable group on carbazole, naphthalene monoimide, and diketopyrrolopyrrole-based solvent-free liquid emitters enabled on-surface polymerization. These emitters alone and in combinations can be directly coated on a glass substrate without the help of solvents. Subsequent photo or thermal polymerization leads to stable, non-sticky, flexible, foldable, and free-standing large-area films with reasonably high quantum yield. Our demonstration of the tunable and white light-emitting films using polymerizable solvent-free liquids might be a potential candidate in flexible/foldable/stretchable electronics. The new concept of polymerizable liquid can be extended to other functional features suitable for futuristic applications.

10aEnergy Transfer10apolymerization10aSolvent-Free Organic Liquids10aThin-Film10aWhite Light1 aWakchaure, Vivek, Chandrakan1 aVeer, Sairam, Dnyaneshwa1 aNidhankar, Aakash, D.1 aKumar, Viksit1 aNarayanan, Aswini1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/polymerizable-solvent-free-organic-liquids-new-approach-large-area-flexible-and-foldable02426nas a2200277 4500008004100000022001400041245012800055210007000183260000900253490000700262520147600269653003801745653001001783653001801793653001701811653000901828100002201837700001801859700003001877700002401907700002001931700002001951700001801971700003001989856012902019 2024 eng d a0947-653900aBoron- and oxygen-doped π-extended helical nanographene with circularly polarised thermally activated delayed fluorescence0 aBoron and oxygendoped πextended helical nanographene with circul cAPR 0 v303 a

Helical nanographenes have garnered substantial attention owing to their finely adjustable optical and semiconducting properties. The strategic integration of both helicity and heteroatoms into the nanographene structure, facilitated by a boron-oxygen-based multiple resonance (MR) thermally activated delayed fluorescence (TADF), elevates its photophysical and chiroptical features. This signifies the introduction of an elegant category of helical nanographene that combines optical (TADF) and chiroptical (CPL) features. In this direction, we report the synthesis, optical, and chiroptical properties of boron, oxygen-doped pi-extended helical nanographene. The pi-extension induces distortion in the DOBNA-incorporated nanographene, endowing a pair of helicenes, (P)-B2NG, and (M)-B2NG exhibiting circularly polarized luminescence with glum of -2.3x10-3 and +2.5x10-3, respectively. B2NG exhibited MR-TADF with a lifetime below 5 mu s, and a reasonably high fluorescence quantum yield (50 %). Our molecular design enriches the optical and chiroptical properties of nanographenes and opens up new opportunities in multidisciplinary fields. B, O-doped pi-extended helical nanographene has been explored for its optical and chiroptical properties. The presence of helical and nanographene segments stabilize the helicity and imparts tunable optical properties. Helical nanographene display circularly polarized thermally activated delayed fluorescence. image

10acircularly polarized luminescence10aDOBNA10adual emission10ananographene10aTADF1 aVenugopal, Geethu1 aKumar, Viksit1 aJadhav, Ashok, Badrinaray1 aDongre, Sangram, D.1 aKhan, Abujunaid1 aGonnade, Rajesh1 aKumar, Jatish1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/boron-and-oxygen-doped-%CF%80-extended-helical-nanographene-circularly-polarised-thermally00867nas a2200229 4500008004100000245011500041210006900156260000800225490000700233653002700240653002500267653003000292653002800322100002500350700001900375700002400394700001800418700003000436700003100466700002000497856012000517 2024 eng d00aExtrusion 3D printing of intrinsically fluorescent thermoplastic polyimide: revealing an undisclosed potential0 aExtrusion 3D printing of intrinsically fluorescent thermoplastic cOCT0 v1610aAdditive manufacturing10afunctional extrusion10ahigh-performance polymers10athermoplastic polyimide1 aKothavade, Premkumar1 aKafi, Abdullah1 aDekiwadia, Chaitali1 aKumar, Viksit1 aSukumaran, Santhosh, Babu1 aShanmuganathan, Kadhiravan1 aBateman, Stuart uhttp://library.ncl.res.in/content/extrusion-3d-printing-intrinsically-fluorescent-thermoplastic-polyimide-revealing01510nas a2200193 4500008004100000022001400041245011000055210007000165260000900235300001600244490000700260520080300267100001801070700002401088700002201112700002201134700003001156856013001186 2024 eng d a1359-734500aTailoring helical ends of π-extended [6]heterohelicenes to control optical, and electrochemical features0 aTailoring helical ends of πextended 6heterohelicenes to control  cOCT  a11944-119470 v603 a

The inherent helical chirality and improved pi-stacking capabilities endow helicenes with fascinating photophysical characteristics when decorated with lateral pi-extensions. Here, we report the synthesis and physicochemical characterization of expanded hetero[6]helicenes fused with thiadiazole and selenadiazole rings at the helical ends. Comparing these heterohelicenes revealed the impact of the heteroatom-embedded aromatic rings on the excited state and redox features. A small structural variation of the terminal rings from thiadiazole to selenadiazole caused a striking change in the heterohelical nanographenes. The inherent helical chirality and improved pi-stacking capabilities endow helicenes with fascinating photophysical characteristics when decorated with heteroatoms.

1 aKumar, Viksit1 aDongre, Sangram, D.1 aVenugopal, Geethu1 aNarayanan, Aswini1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/tailoring-helical-ends-%CF%80-extended-6heterohelicenes-control-optical-and-electrochemical02167nas a2200253 4500008004100000245009100041210006900132260000900201300001500210490000700225520131300232653003801545653002301583653001301606653001701619653001801636100002401654700002201678700001801700700003001718700001801748700003001766856011701796 2025 eng d00aChiroptical amplification of [7]-helicene nanographene by additional helical chirality0 aChiroptical amplification of 7helicene nanographene by additiona cFEB  ae2024207670 v643 a

Nanographenes have captivated scientific interest since the pioneering discovery of graphene. Recently, attention has shifted towards exploring chiral and nonplanar nanographenes, for their distinct optical, chiroptical, and electronic properties. Despite the growing acceptance of helicenes, the research on inducing helical chirality on pi-extended derivatives to boost chiroptical properties remains unattended. In our study, we introduce a new pi-extended [7]-helicene resulting from the condensation of diamines with 3,6-dibromophenanthrene-9,10-dione, complemented by two hexabenzocoronene arms in the periphery. Notably, the nanographene containing binaphtho-[1,4]diazocine, compared to the corresponding phenazine, exhibits a remarkable average 2.5, 5, and 10-fold enhancements in quantum yield, dissymmetry factor, and brightness, respectively, when measured in five different solvents. These improvements underscore the significance of the induced helical chirality by the antiaromatic binaphtho-[1,4]diazocine in influencing the chiroptical properties of the helical nanographene. Our research represents a significant stride toward unlocking the potential of pi-extended helicenes and lays the groundwork for further exploration in designing and synthesizing new chiral nanomaterials.

10acircularly polarised luminescence10adissymmetry factor10ahelicene10ananographene10aquantum yield1 aDongre, Sangram, D.1 aVenugopal, Geethu1 aKumar, Viksit1 aJadhav, Ashok, Badrinaray1 aKumar, Jatish1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/chiroptical-amplification-7-helicene-nanographene-additional-helical-chirality02406nas a2200313 4500008004100000245008500041210007000126260000800196300001500204490000700219520144500226653001401671653000801685653001401693653001701707653002001724653000901744100001801753700002201771700003001793700002401823700002001847700001801867700001901885700001901904700002101923700003001944856011801974 2025 eng d00aRegioisomeric π-extended nanographene with long-lived phosphorescence afterglow0 aRegioisomeric πextended nanographene with longlived phosphoresce cFEB ae2024221250 v643 a

The cutouts of graphene sheets, particularly those with a nonplanar topology, present vast opportunities for advancement. Even a slight deviation from the planar structure can lead to intriguing (chiro)optical features for helically twisted nanographenes. In this context, we introduce two regioisomeric pi-extended nanographenes that exhibit distinct excited-state characteristics. The helicene structure and the photophysical features can be easily tuned by changing the connecting position of the nanographene to the carbazole core (2,7- and 3,6-). Single-crystal X-ray diffraction analysis confirmed the formation of nanographenes with bent and helical conformations. Both derivatives exhibited thermally activated delayed fluorescence at room temperature and phosphorescence at low temperatures. Notably, the nanographene with the bent structure displayed an impressive red afterglow lasting over 30seconds, in contrast to the very weak afterglow observed in the helical structure. DFT calculations revealed the existence of an isoenergetic higher triplet state (T-8) and comparatively weak spin-orbit coupling (T-1-S-0), thereby enabling the bent nanographene to exhibit a long-lived component and strong afterglow. Our findings highlight the significance of regioisomeric nanographenes with exceptional optical properties and offer a deeper understanding of the structure-property relationship in nonplanar nanographenes.

10aAfterglow10aCPL10aHelicenes10ananographene10aPhosphorescence10aTADF1 aKumar, Viksit1 aVenugopal, Geethu1 aJadhav, Ashok, Badrinaray1 aDongre, Sangram, D.1 aGonnade, Rajesh1 aKumar, Jatish1 aRuer, Paul, C.1 aHupp, Benjamin1 aSteffen, Andreas1 aBabu, Sukumaran, Santhosh uhttp://library.ncl.res.in/content/regioisomeric-%CF%80-extended-nanographene-long-lived-phosphorescence-afterglow