Dataset Information

Functional Molecular System of Bis(pyrazolyl)pyridine Derivatives: Photophysics, Spectroscopy, Computation, and Ion Sensing.

ABSTRACT: A new series of conjugated donor-?-acceptor type of 2,6-bis(pyrazolyl)pyridine derivatives (compounds IK-(3-9)) have been synthesized via Horner-Wadsworth-Emmons (HWE) reaction, starting from a common phosphonate precursor and diverse donor aromatic aldehydes and characterized by routine spectral analysis including elemental analysis. Compound IK-2, one of the starting precursors, and molecule IK-3, the first member of the donor-?-acceptor series, are additionally characterized by single-crystal X-ray structure determination. Compounds IK-2 and IK-3 are crystallized in P1? (triclinic) and P2₁/c (monoclinic) space groups, respectively. The absorption maxima in the electronic spectra of the title compounds shift mainly due to intramolecular charge transfer (ICT) between different donor (dibutyl and cyclic pyrrolidine) groups and the acceptor moiety [2,6-bis(pyrazolyl) pyridine]. Solution-state emission spectral studies of all these compounds show large solvent sensitive behavior with significant amounts of Stokes shifts. The large solvent dependence of the emission indicates that the excited state is stabilized in more polar solvents due to the ICT. All chromophores exhibit solid-state fluorescence behavior except compound IK-7. The role of the position and nature of the donor functionalities in the conjugated backbone of overall donor moiety of compounds IK-(3-9), on the electronic absorption properties of the title chromophores has been demonstrated, which has further been corroborated by density functional theory (DFT) and time-dependent DFT (TDDFT) computational studies. The emission spectral results of compounds IK-3, IK-5, and IK-7 have also been supported by the DFT and TDDFT calculations. A fluorescence lifetime study on this series also shows that the excited states are stabilized in more polar solvents. Finally, one of the chromophores (chromophore IK-4) in the title series has been shown to act as a selective molecular sensor (turn-off switch) for the Cu(II) ion.

SUBMITTER: Naik IK

PROVIDER: S-EPMC6641288 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Functional Molecular System of Bis(pyrazolyl)pyridine Derivatives: Photophysics, Spectroscopy, Computation, and Ion Sensing.

Naik Indravath K IK Bodapati Ramakrishna R Sarkar Rudraditya R Mondal Navendu N Das Samar K SK

ACS omega 20180313 3

A new series of conjugated donor-π-acceptor type of 2,6-bis(pyrazolyl)pyridine derivatives (compounds IK-(3-9)) have been synthesized via Horner-Wadsworth-Emmons (HWE) reaction, starting from a common phosphonate precursor and diverse donor aromatic aldehydes and characterized by routine spectral analysis including elemental analysis. Compound IK-2, one of the starting precursors, and molecule IK-3, the first member of the donor-π-acceptor series, are additionally characteri ...[more]

PMID: 31458568

Similar Datasets

Project description:Rapid and efficient analysis of fluoride ion is crucial to providing key information for fluoride ion hazard assessment and pollution management. In this study, we synthesized one symmetrical structure called 1,4-bis(4,5-diphenyl-1H-imidazol-2-yl)benzene (1a) and two asymmetrical structures, namely 2-(4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl)-1H-phenanthro(9,10-d)imidazole (1b) and 2-(4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl)-1H-imidazo(4,5-f)(1,10)phenanthroline (1c), which served as an efficient anion sensor for fluoride ion over a wide range of other anions (Cl-, Br-, I-, NO₃-, ClO₄-, HSO₄-, BF₄-, and PF₆-) owing to imidazole group in the main backbone. The absorption intensity of compound 1a at λmax 358 nm slightly decreased; however, a new band at λmax 414 nm appeared upon the addition of fluoride ion, while no evident change occurred upon the addition of eight other anions. The photoluminescence intensity of compound 1a at λmax 426 nm was nearly quenched and fluorescence emission spectra were broadened when fluoride ion was added into dimethyl sulfoxide (DMSO) solution of compound 1a. Compared with the optical behaviors of the DMSO solution of compound 1a in the presence of Bu₄N⁺F-, compounds 1b and 1c exhibited considerable sensitivity to fluoride ion due to the increase in coplanarity. Furthermore, compared with the fluorescence emission behaviors of the DMSO solutions of compounds 1a and 1b in the presence of Bu₄N⁺F-, compound 1c exhibited the most significant sensitivity to fluoride ion due to the charge transfer enhancement. Consequently, the detection limits of compounds 1a-1c increased from 5.47 × 10-6 M to 4.21 × 10-6 M to 9.12 × 10-7 M. Furthermore, the largest red shift (75 nm) of the DMSO solution compound 1c in the presence of fluoride ion can be observed. Our results suggest that the increase in coplanarity and the introduction of electron-withdrawing groups to the imidazole backbone can improve the performance in detecting fluoride ion.

Dataset Information

Functional Molecular System of Bis(pyrazolyl)pyridine Derivatives: Photophysics, Spectroscopy, Computation, and Ion Sensing.

Publications

Functional Molecular System of Bis(pyrazolyl)pyridine Derivatives: Photophysics, Spectroscopy, Computation, and Ion Sensing.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets