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A [3 + 2] cycloaddition reaction using dialkyne and diazide comonomers, both bearing explosophoric groups, to synthesize energetic polymers containing furazan and 1,2,3-triazole ring as well as nitramine group in the polymer chain have been described. The developed solvent- and catalyst-free approach is methodologically simple and effective, the comonomers used are easily available, and the resulting polymer does not need any purification. All this makes it a promising tool for the synthesis of energetic polymers. The protocol was utilized to generate multigram quantities of the target polymer, which has been comprehensively investigated. The resulting polymer was fully characterized by spectral and physico-chemical methods. Compatibility with energetic plasticizers, thermochemical characteristics, and combustion features indicate the prospects of this polymer as a binder base for energetic materials. The polymer of this study surpasses the benchmark energetic polymer, nitrocellulose (NC), in a number of properties.

We have designed a new medium bandgap non-fullerene small-molecule acceptor consisting of an IDT donor core flanked with 2-(6-oxo-5,6-dihydro-4 H -cyclopenta[ c ]-thiophene-4-ylidene) malononitrile (TC) acceptor terminal groups ( IDT-TC ) and compared its optical and electrochemical properties with the IDT-IC acceptor. IDT-TC showed an absorption profile from 300 to 760 nm, and it has an optical bandgap of 1.65 eV and HOMO and LUMO energy levels of -5.55 and -3.83 eV, respectively. In contrast to IDT-IC, IDT-TC has an upshifted LUMO energy level, which is advantageous for achieving high open-circuit voltage. Moreover, IDT-TC showed higher crystallinity and high electron mobility than IDT-IC. Using a wide bandgap D-A copolymer P as the donor, we compared the photovoltaic performance of IDT-TC , IDT-IC, and IDT-IC-Cl nonfullerene acceptors (NFAs). Polymer solar cells (PSCs) using P: IDT-TC , P: IDT-IC, and P:IDT-IC-Cl active layers achieved a power conversion efficiency (PCE) of 14.26, 11.56, and 13.34%, respectively. As the absorption profiles of IDT-IC-Cl and IDT-TC are complementary to each other, we have incorporated IDT-TC as the guest acceptor in the P: IDT-IC-Cl active layer to fabricate the ternary (P: IDT-TC : IDT-IC-Cl) PSC, demonstrating a PCE of 16.44%, which is significantly higher than that of the binary BHJ devices. The improvement in PCE for ternary PSCs is attributed to the efficient exploitation of excitons via energy transfer from IDT-TC to IDT-IC-Cl, suitable nanoscale phase separation, compact stacking distance, and more evenly distributed charge transport., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Donor-acceptor-acceptor (D-A-A) type 1,8-naphthalimide based small molecules SM1 and SM2 functionalized with tetracyanobutadiene (TCBD) and dicyanoquino-dimethane (DCNQ) modules, showing strong absorption in the visible and near-infrared (NIR) region are reported. TCBD and DCNQ linked SM1 and SM2 exhibit multi-redox waves. The electrochemical and optical HOMO-LUMO gaps show similar trends. These SMs exhibit a broad absorption profile which is complementary to the D-A copolymer P donor and also possess an appropriate lowest unoccupied molecular orbital (LUMO) to serve as an acceptor with P with a LUMO level of -3.33 eV. The organic solar cells based on P : SM1 and P : SM2 exhibit a PCE of 4.94% and 6.11%, respectively. The higher value of the PCE for the SM2 based organic solar cells has been attributed to the broader absorption profile, more balanced charge transport and lower photon energy loss. The values of V oc of the organic solar cells for the SM1 acceptor (1.06 V and 1.02 V without and with solvent additive) are the highest values reported for devices based on non-fullerene acceptors to the best of our knowledge. The energy loss ( E loss ) of 0.56 eV and 0.48 eV for SM1 and SM2 based devices, respectively is one of the smallest reported for BHJ organic solar cells.