New Di-, Tri-, and Tetra-Core-Functionalized Naphthalene Diimides from Reactions of Allyl Ethers with Lewis Acids

Core-substituted NDIs bearing aryl allyl ethers have a predisposition to deallylation in the presence of Lewis Acids (LA). However, under certain conditions, with appropriate choice of LA, the reaction can be controlled to yield unexpected and highly functionalized dinaphthol systems through a [3,3]-sigmatropic (Claisen) rearrangement. The major products of the rearrangement study have been characterized by X-ray crystallographic analysis and the per-substituted products are shown to undergo ring-closing metathesis to form heterocyclic core-extended NDIs. This study highlights a simple method to construct a series of important donor–acceptor building blocks for the preparation of new conjugated materials

Fluorescent carbon dots based phytosensor for indoor formaldehyde pollution monitoring

abstract: Indoor formaldehyde pollution released from household products is one of the major causes of several health diseases. Ornamental plants have been paid more attention recently to improve air quality and increase natural decorative appeal. Therefore, we aimed to use ornamental plants as a plant-based biosensor or phytosensor to monitor/detect indoor formaldehyde exposure. The synthesized carbon dots with nitrogen doping (N-doped CDs) in this study shows a big “turn-off” significant response with high selectivity to formaldehyde. The lowest formaldehyde concentration that gave the observable fluorescence quenching signal by naked eye on Fittonia albivenis (Nerve Plant) was 50.0 μg/L, which is lower than the exposure limit of 80.0 μg/L as indicated by World Health Organization. The results showed that ornamental plants with the aid of N-doped CDs can be developed into phytosensor for formaldehyde detection. Furthermore, findings in this study will be useful for the development of plant biosensor for other indoor air pollution monitoring

New Di-, Tri-, and Tetra-Core-Functionalized Naphthalene Diimides from Reactions of Allyl Ethers with Lewis Acids

Core-substituted NDIs bearing aryl allyl ethers have a predisposition to deallylation in the presence of Lewis Acids (LA). However, under certain conditions, with appropriate choice of LA, the reaction can be controlled to yield unexpected and highly functionalized dinaphthol systems through a [3,3]-sigmatropic (Claisen) rearrangement. The major products of the rearrangement study have been characterized by X-ray crystallographic analysis and the per-substituted products are shown to undergo ring-closing metathesis to form heterocyclic core-extended NDIs. This study highlights a simple method to construct a series of important donor-acceptor building blocks for the preparation of new conjugated materials

Synthesis of Novel Fluorescent Sensors Based on Naphthalimide Fluorophores for the Highly Selective Hg2+-Sensing

With an aim to develop the new sensors for optical detection of Hg2+ ions, two novel fluorometric sensors were designed and successfully prepared using 2-(3-(2-aminoethylsulfanyl)propylsulfanyl)ethanamine and one or two N-methylnaphthalimide moieties (1 and 2). Sensor 1 was obtained via N-alkylation, N-imidation and a one-pot nucleophilic aromatic substitution, and N-formylation of the amine, while sensor 2 was prepared via N-alkylation, N-imidation, and nucleophilic aromatic substitution. The characterization, including 1H NMR, 13C NMR, and mass spectrometry, was then performed for 1 and 2. The Hg2+-binding behaviors of the sensors were investigated in terms of sensitivity and selectivity by fluorescence spectroscopy. Sensor 1 especially provided the reversible and highly Hg2+-selective ON-OFF fluorescence behavior by discriminating various interfering ions such as Pb2+, Co2+, Cd2+, Mn2+, Fe2+, K+, Na+, and in particular Cu2+ and Ag+ with a detection limit of 22 ppb toward Hg2+ ions