Finding New Precursors for Light Harvesting Materials: A Computational Study of the Fluorescence Potential of Benzanthrone Dyes

Green synthesis of novel spiropyrazoline-indolinones in neutral deep eutectic solvents and DFT studies

Novel spiropyrazoline-indolinones (4a-t) have been synthesized successfully in neutral deep eutectic solvents by reacting 5-Cl/Br-isatin (1a-b) with aromatic ketones (2a-b) and a variety of substituted hydrazines (3a-e) in good to excellent yields. This eco-friendly straightforward synthetic protocol discloses good functional group compatibility. The conventional synthetic approach was compared with the greener route of microwave-assisted synthesis of spiropyrazolines using ethanol. This approach utilized mild reaction conditions which furnished high yields in short reaction time employing one pot two-step multicomponent. All new compounds were structurally confirmed by detailed spectroscopic analysis and density functional theory calculations. This method provides efficient access to spiropyrazole derivatives using biodegradable and green solvent.

Synthesis and Properties of New 3-Heterylamino-Substituted 9-Nitrobenzanthrone Derivatives

In the present study, new fluorophores based on disubstituted benzanthrone derivatives were designed starting from 9-nitro-3-bromobenzanthrone with nucleophilic substitution of the bromine atom with some secondary cyclic amines. It has been found that this reaction is positively affected by the presence of a nitro group in comparison with 3-bromobenzanthrone. The new compounds exhibit intense absorption and pronounced luminescent properties in various organic solvents. In this regard, their photophysical properties were evaluated with an experimental study of the solvatochromic behavior of the obtained compounds in various solvents. It has recently been found that the addition of an electron-withdrawing nitro group to the benzanthrone core increases its first- and second-order hyperpolarizability. Such dyes can be used in the fabrication of optical limiter devices. Therefore, the developed fluorescent molecules have a potential prospect for extensive application in optoelectronics.

N′-(3-Bromo-7-oxo-7H-benzo[de]anthracen-9-yl)-N,N-dimethylimidoformamide

We report a synthesis of 3-bromo-9-N′-(N,N-dimethylformamidino)benzanthrone in good yield by a condensation reaction of 3-bromo-9-aminobenzanthrone with dimethylformamide in the presence of phosphorous oxychloride. The structure of the synthesized amidine was characterized by FTIR-ATR, NMR experiments, and elemental analysis. The title compound was analyzed by UV-Vis and fluorescence spectroscopy in various organic solvents.