[1,2,3]-triazole derivatives: Mesomorphic property dependence on the molecular shape

Nowadays, heterocyclic units have been extensively studied for the preparation of thermotropic liquid crystals due to their ability to impartlateral and/or longitudinal dipoles and induce changes in molecular shape. Key parameters to accede to stable mesophases are the positionof the heterocycle and the nature of terminal and linking functions. We present in this paper, an overview of several series of 1,2,3-triazole liquidcrystalline derivatives thatwe designed and characterized.We highlight the effect of different connecting functions and the geometry of mesogeniccore on the mesomorphic behavior of these derivatives

Blue luminescent cyanopyridone based molecular architectures: A structure-property study

A new class of molecular architecture made of five conjugated rings carrying terminal methyl or variable alkoxy (chain lengths of 4, 6, 8, or 16) substituted at para positions has been synthesized. Among the five rings, two rings are of cyanopyridones utilized as an electron deficient N-heterocycle along with blue luminescent motif, and the rest of them are phenylene motifs. All the compounds produced good yield and ATR-IR, NMR and Mass spectroscopy confirmed their structures. Further, the compounds were stable up to ≈200 °C and the degradation occurs at higher temperature as evident from the TGA analysis. The mesomorphic study reveals that compound is only having very long terminal n-hexadecyloxy substituents appeared in-layers liquid crystalline organization as confirmed by POM and variable temperature XRD analysis. Further, the compounds showed intense blue fluorescence in both solution as well as solid state and their fluorescence quantum yields are dependent on the length of alkoxy chains. Calculated HOMO/LUMO levels by cyclic voltammetry measurements revealed that the compounds are ambipolar in nature and cited as an ideal candidates for electroluminescent applications.This research was supported by the Science & Engineering Research Board (SERB) under Young Scientists Scheme (Project File no.: YSS/2014/000835), Govt. of India, New Delhi. The author acknowledges the Mysore University, Mysore for the instrumental analysis. The authors also acknowledge the Ape instrument, Italy for AFM analysis. J. B. and M. B. R. have been financially supported by MINECO-FEDER of Spain-UE (Projects MAT2014-55205-P, CTQ2015-70174P, and MAT2015-66208-C3-1-P) and the Aragón Government and FSE (Project E04).Peer reviewe

Variation of the donor and acceptor in D-A-pi-A based cyanopyridine dyes and its effect on dye sensitized solar cells

Two metal free organic dyes (TPCTh and TPCRh) with D-A-pi-A configuration, having 3-cyanopyridine as an auxiliary acceptor and thiophene pi-linkers along with a triphenylamine donor and cyanoacetic acid/rhodanine-3-acetic acid anchoring groups, were successfully synthesized and utilized as sensitizers in the fabrication of dye-sensitized solar cells (DSSCs). The opto-electronic properties of TPCTh and TPCRh were compared with the model sensitizer CCTh having carbazole as the donor and cyanoacetic acid as the anchoring group. Both the dyes showed red shifted absorption spectra compared to the standard CCTh dye. Also, TPCRh showed a broader absorption spectrum with a reduced band gap compared to TPCTh. However, theoretical studies indicate that the unavailability of excited state conjugation over the anchoring group could lead to restricted charge injection for the TPCRh dye, whereas the TPCTh dye exhibits complete conjugation over the entire molecule. The photovoltaic performance of the TPCTh dye was found to be better compared with the standard CCTh sensitizer as a result of better absorption contributed by the lower band gap in TPCTh leading to improved photon-light conversion and thus an improved J(sc) of 11 mA cm(-2) over the 7.12 mA cm(-2) of CCTh. In addition, lifetime measurements corroborated a lower electron lifetime for TPCRh compared to TPCTh and CCTh

Flexible, biodegradable and recyclable solar cells: a review

Solar energy is conceivably the largest source of renewable energy at our disposal, but vital advances are expected to make solar cells economically viable. Biodegradable and flexible solar cells are currently under extensive investigation for environmentally-friendly electronic applications. Biomaterials based solar cell is emerging due to their sustainable, scalable, abundant, renewable, and environmentally-friendly energy production. This review highlights recent research progress in the emerging group of biomaterials and their integration for flexible solar cell devices. The more emphasis is given to the absolute recyclable solar cell technology, processing conditions and optimized processing conditions to produce a high amount of energy. This review briefly describes the recent progress in these classes of material, covering substrates and semiconductors. A prominent demand still exists for a next-generation of flexible, biodegradable and biocompatible solar cell substrate for ultimate energy generation application.Acknowledgements This publication was made possible by the support of an UREP grant from the Qatar National Research Fund (UREP23-116-2-041). The statements made herein are solely the responsibility of the authors. Dr. Ahipa T. N. is grateful to the Centre for Nano and Material Sciences, Jain University, Jain Global Campus, Jakkasandra Post, Kanakapura Taluk, Ramanagara-562112, India for providing necessary facilities. This research was supported by the Science & Engineering Research Board (SERB) (Project File No.: YSS/2014/000835) under Young Scientists Scheme, Govt. of India, New Delhi.Scopu