The vertical excitation energies of 13 BODIPY based dye sensitizers are benchmarked by means of TD-DFT, using 36 functionals from different DFT rungs. Most TD-DFT results were found to overestimate the excitation energies, and show mean absolute error (MAE) values in the range 0.2–0.5 eV. The dispersion-corrected, spin-component-scaled, double-hybrid (DSD) functionals DSD-BLYP and DSD-PBEP86 were found to have the smallest MAE values of 0.083 eV and 0.106 eV, respectively, which is close to the range of average errors found in the more expensive coupled-cluster methods. Moreover, DSD-BLYP and DSD-PBEP86 functionals show excellent consistency and quality of results (standard deviation = 0.048 eV and 0.069 eV respectively). However, the range separated hybrid (RSH) and the range separated double hybrid (RSDH) functionals were found to provide the best predictability (linear determination coefficient R² > 0.97 eV).

This study aimed to clarify the physico-chemical properties of cucurbit[7]uril (CB[7]) and cinnamaldehyde (Cinn) inclusion complexes (CB[7]–Cinn) and their resulting antitumor activity. CB[7]–Cinn inclusion complexes were prepared by a simple experimental approach and fully characterized for their stoichiometry, formation constant, particle size and morphology. Quantum chemical calculations were performed to elucidate the stable molecular structures of the inclusion complexes and their precursors and to investigate the probable stoichiometry and direction of interaction using three different DFT functionals at the 6-31G(d,p) basis set. The UV-vis spectrophotometric titrations as well as the Job plot, based on ¹H NMR spectroscopy, suggested 1 : 1 and 1 : 2 stoichiometries of CB[7] : Cinn. The formation constants of the complexes were calculated using Benesi–Hildebrand equations and non-linear fittings. Moreover, the theoretical calculations confirmed the potential formation of 1 : 1 and 1 : 2 stoichiometries and clarify the orientation of binding from the Cinn phenyl moiety. The nanoparticles' TEM images showed a crystal-like spherical shape, smooth surface, with a small tendency to agglomerate. CB[7]–Cinn inclusion complexes were analyzed for their antitumor activity against MDA-MB-231 breast cancer and U-87 glioblastoma cell lines. The IC₅₀ values were calculated after 72 hours of incubation with different concentrations of CB[7]–Cinn inclusion complexes and compared to free Cinn and free CB[7]. The IC₅₀ values for free Cinn and CB[7]–Cinn inclusion complexes were 240.17 ± 32.46 μM and 260.47 ± 20.83 μM against U-87 cells and 85.93 ± 3.35 μM and 176.3 ± 7.79 μM against MDA-MB-231 cells, respectively, despite the enhanced aqueous solubility. No significant cytotoxicity was noticed for the free CB[7].

CO₂ fixation is a prominent research theme that attracts the attention of scientists, stakeholders and governmental entities with the aim of ultimately bringing commercial products to the market. Herein, a series of mono-, bi-functional and polymeric imidazolium-based catalysts were synthesized and utilized for the production of cyclic carbonates (CCs) using epoxides and 1 bar of CO₂ under mild reaction conditions. In addition, three onium salts, namely, ammonium, phosphonium, and pyridinium, were synthesized and characterized using ¹H/¹³C nuclear magnetic resonance (NMR) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopies, together with thermal gravimetric analysis (TGA), high-resolution mass spectrometry (HRMS) and elemental analysis (EA). All the investigated organocatalysts showed almost quantitative CC conversions, which were isolated from the crude reaction and identified spectroscopically. Density functional theory (DFT) calculations revealed that the aforementioned onium salts followed the same detailed mechanism for the cycloaddition reaction, which started with the electrostatic interaction of the onium centers with the oxygen atom of the epoxide. Even in the case of the imidazolium nucleus, the acidic C2 proton played a marginal role in the epoxide activation than in the ring-opening step.

The absorption spectra modeled as the vertical excitation energies of 13 dye sensitizers used in dye-sensitized solar cells (DSSCs) are benchmarked by means of time-dependent (TD)-DFT, using 36 functionals from different DFT rungs.