A Y-shaped push-pull dye () with ,-dimethylanilino donors and a benzonitrile acceptor connected via an imidazole-based π-conjugated spacer was designed. It showed a dark yellow color in solution due to facile intramolecular charge-transfer interaction, but no fluorescence was detected, presumably due to the photo-induced electron transfer effect of the imidazole moiety. However, addition of nerve agents such as diethyl chlorophosphate (DCP, sarin mimic) and diethyl cyanophosphate (DCNP, Tabun mimic) resulted in a blue-colored fluorescence with fading of the native dark yellow color. Mechanistic studies indicated nucleophilic attack of imidazole at the phosphorus of DCP or DCNP, leading to the formation of a phosphorylated intermediate, which undergoes time-dependent hydrolysis (∼24 h) in aqueous medium. This process recovers the free probe (enzyme-like behavior) and releases a less-toxic organophosphate compound as the byproduct. The phosphorylated derivative of , formed during such interaction, shows a different electronic behavior, which reduces the extent of charge-transfer interaction as well as nonradiative decay and supports emissive properties. Considering the high sensitivity of towards DCP and DCNP with LOD 35 and 42 ppb, we prepared easy test strips for on-site vapor-phase detection of nerve agents.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.joc.1c01488 | DOI Listing |
J Org Chem
December 2024
Department of Chemistry, Birla Institute of Technology and Science, Pilani, Telangana 500078, India.
Optical detection of the HSO ion in pure aqueous medium is rare, owing to the very high Gibbs free energy of hydration and ambiguity to distinguish with the isostructural HPO ion. Herein, a pair of triphenylamine-based push-pull dyes with different numbers of terminal pyridine fragments, connected via an acetylenic linker, were synthesized by Sonogashira cross-coupling reaction. These two dyes displayed highly selective (LOD = 15.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2023
Caruso Department of Otolaryngology, University of Southern California, Los Angeles, CA 90033.
The intricate, crystalline cytoarchitecture of the mammalian organ of Corti presumably plays an important role in cochlear amplification. As currently understood, the oblique, Y-shaped arrangement of the outer hair cells (OHCs) and phalangeal processes of the Deiters cells serves to create differential "push-pull" forces that drive the motion of the basilar membrane via the spatial feedforward and/or feedbackward of OHC forces. In concert with the cochlear traveling wave, the longitudinal separation between OHC sensing and forcing creates phase shifts that yield a form of negative damping, amplifying waves as they propagate.
View Article and Find Full Text PDFJ Org Chem
November 2021
Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India.
A Y-shaped push-pull dye () with ,-dimethylanilino donors and a benzonitrile acceptor connected via an imidazole-based π-conjugated spacer was designed. It showed a dark yellow color in solution due to facile intramolecular charge-transfer interaction, but no fluorescence was detected, presumably due to the photo-induced electron transfer effect of the imidazole moiety. However, addition of nerve agents such as diethyl chlorophosphate (DCP, sarin mimic) and diethyl cyanophosphate (DCNP, Tabun mimic) resulted in a blue-colored fluorescence with fading of the native dark yellow color.
View Article and Find Full Text PDFJ Mol Model
April 2021
Laboratory of Applied Thermodynamics and Molecular Modeling, Department of Chemistry, Faculty of Science, University of Tlemcen, PB 119, 13000, Tlemcen, Algeria.
A theoretical analysis of a series of imidazole-based Y-shaped chromophores, D1-D8, is performed in order to investigate their non(linear) optical, fluorescence, and charge-transport properties. The calculations have been carried out employing DFT and TD-DFT methods at CAM-B3LYP and M06-2X levels of theory. FMO analysis reveals that in ground state, the highest occupied molecular orbital is localized on the 4,5-dimethylanilino donor moiety and imidazole core while the lowest unoccupied molecular orbital spreads on π-linker and nitro acceptor moieties.
View Article and Find Full Text PDFJ Org Chem
February 2021
Instituto de Nanociencia y Materiales de Aragón (INMA)-Departamento de Química Orgánica, CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain.
Three series of push-pull derivatives bearing 4-pyranylidene as electron donor group and a variety of acceptors were designed. On one hand, one-dimensional chromophores with a thiophene ring (series ) or 5-dimethylaminothiophene moiety (series ) as an auxiliary donor, non-coplanar with the π-conjugated system, were synthesized. On the other hand, related two-dimensional (2D) Y-shaped chromophores (series ) were also prepared to compare how the diverse architectures affect the electrochemical, linear, and second-order nonlinear optical (NLO) properties.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!