articles in 2024

The circularly polarized luminescence (CPL) spectra of S- and X-shaped double helicenes exhibit distinct vibrational structures and overall shape variations. In this study, we conducted an in-depth investigation into the vibronic effects influencing the CPL spectra of two double helicenes, namely DPC and DNH. Employing state-of-the-art computations utilizing the FC-HT1|VH model at the CAM−B3LYP/def2-TZVP level, we unveiled the paramount impact of Franck–Condon (FC), Herzberg-Teller (HT), and Duschinsky effects on their chiroptical responses. Our research underscores the pivotal role of structural deformations associated with the S1-to-S0 electronic transition in molding CPL spectra and wavelength-dependent dissymmetry (g) factor values, as well as the significance of HT effects in shaping and enhancing CPL responses. This extensive investigation not only advances our comprehension of the vibronic characteristics in configurationally distinct double helicenes but also offers valuable insights for the design of chiral molecules featuring controllable or finely-tunable CPL responses.

Nitro Lophines were readily synthesized via multicomponent reaction of benzil, nitro benzaldehyde and ammonium acetate. All three nitro Lophines were isolated in good yields and were also characterized by various analytical and spectroscopic techniques. A distinctive solvatochromism was observed in case of ortho and para nitro containing Lophines in their absorbance spectra. In particular, naked eye solvatochromism was observed, in case of para nitro Lophine, in the form of yellow and red coloured solution in methanol and DMSO respectively. Halochromism studies revealed the hypsochromic shift under acidic pH while bathochromic shift under alkaline pH for both nitro Lophines. Again the para nitro Lophine demonstrated wonderful distinctive colour change under acidic and alkaline pH in both methanol and DMSO as solvents. The measurement of absorbance at different pH values was carried out and the data obtained were used for calculation of dissociation constants employing several graphical methods. Computational calculations were carried out using TD-DFT for UV–Vis absorption calculation while graph-convolutional neural network model was utilized for calculation of dissociation constants. Ultimately, a reusable naked eye pH detection paper could be developed using para nitro Lophine as a sole indicator.

Development of two-dimensional materials and exploration of their functionalities are significant challenges due to their potential. In this study, we successfully fabricated a supramolecular nanosheet composed of amphiphilic Rose Bengal dyes in an aqueous medium. Furthermore, we elucidated a distinct change in the photosensitisation mechanism induced by nanosheet formation.

The significance of chiral molecules in advanced materials and technologies is undeniable in chemistry yet designing them with desired chiroptical properties lacks reliable strategies.