Currently, polymer organic solar cells (POSCs) are widely utilized due to their significant application, such as low-cost power conversion efficiencies (PCEs). Therefore, we designed a series of photovoltaic materials (D1, D2, D3, D5 and D7) by the incorporation of selenophene units (n = 1–7) as π₁-spacers by considering the importance of POSCs. Density functional theory (DFT) calculations were accomplished at MPW1PW91/6-311G (d, p) functional to explore the impact of additional selenophene units on the photovoltaic behavior of the above-mentioned compounds. A comparative analysis was conducted for designed compounds and reference compounds (D1). Reduction in energy gaps (∆E = 2.399 − 2.064 eV) with broader absorption wavelength (λ_max = 655.480 − 728.376 nm) in chloroform along with larger charge transference rate was studied with the addition of selenophene units as compared to D1. A significantly higher exciton dissociation rate was studied as lower values of binding energy (E_b = 0.508 − 0.362 eV) were noted in derivatives than in the reference (E_b = 0.526 eV). Moreover, transition density matrix (TDM) and density of state (DOS) data also supported the efficient charge transition origination from HOMOs to LUMOs. Open circuit voltage (V_oc) was also calculated for all the aforesaid compounds to check the efficiency, and significant results were seen (1.633–1.549 V). All the analyses supported our compounds as efficient POSCs materials with significant efficacy. These compounds might encourage the experimental researchers to synthesize them due to proficient photovoltaic materials.

Chitosan-bounded copper (chitosan–Cu) was introduced for green synthesis of novel ferrocenated spiropyrrolidine hybrids, namely 3′-(4-.bromobenzoyl)-5′-(4-hydroxybenzyl)-4′-ferrocenylspiro[indoline-3,2′-pyrrolidin]-2-one and 3′-(4-bromobenzoyl)-4′-ferrocenylspiro[indoline-3,2′-pyrrolidin]-2-one, in good yield. A one-pot three-component 1,3-dipolar cycloaddition reaction was employed for the formation of spiropyrrolidines from 1-(4-bromophenyl)-ferrocene-prop-2-en-1-one and azomethine ylides, which were developed in situ from tyrosine, glycine, and isatin, respectively. Various spectroscopic methods were used to establish the structures of spiropyrrolidines, and a single crystal X-ray diffraction study of a spiropyrrolidine provided additional confirmation. The crystallographic study revealed that compound 3a has one independent molecule in its unit cell, which is correlated with Hirshfeld surface analysis, and describes intramolecular contacts adversely. The highly yielded products in green conditions were determined for their antibacterial significance and were found to have good activity against Gram-positive and Gram-negative bacterial strains.

The novel piperidinium dicoumarol has been synthesized by the reaction of 3-formylchromone, 4-hydroxycoumarin, and piperidine under chitosan catalyzed solvent-free green conditions. FT-IR and NMR spectroscopy established the structure of dicoumarol, which was further confirmed by a single X-ray diffraction study. The single diffraction study has revealed the hydrogen bonding interactions, which were further validated by Hirshfeld surface analysis. Geometry optimizations of dicoumarol have been performed at the DFT level of theory by the B3LYP acting along with Gaussian 16, revision B.01 to calculate the geometric and electronic structure parameters.

This review highlights mechanochemical strategies for CO ₂ reduction catalysis, enabling sustainable pathways toward carbon-neutral products and environmental remediation.