10.1021/acsomega.7b02006.s001
Indravath
K. Naik
Indravath
K.
Naik
Ramakrishna Bodapati
Ramakrishna
Bodapati
Rudraditya Sarkar
Rudraditya
Sarkar
Navendu Mondal
Navendu
Mondal
Samar K. Das
Samar K.
Das
Functional Molecular System of Bis(pyrazolyl)pyridine
Derivatives: Photophysics, Spectroscopy, Computation, and Ion Sensing
American Chemical Society
2018
compounds IK -3
title compounds shift
absorption maxima
chromophores exhibit
Compounds IK -2
time-dependent DFT
donor moiety
Compound IK -2
cyclic pyrrolidine
single-crystal X-ray structure determination
molecule IK -3
Functional Molecular System
title chromophores
IK -7
fluorescence lifetime study
chromophore IK -4
HWE
TDDFT calculations
intramolecular charge transfer
title series
IK -3
Stokes shifts
fluorescence behavior
turn-off switch
space groups
compounds show
compound IK -7
absorption properties
donor functionalities
ICT
phosphonate precursor
2018-03-13 08:13:47
Dataset
https://acs.figshare.com/articles/dataset/Functional_Molecular_System_of_Bis_pyrazolyl_pyridine_Derivatives_Photophysics_Spectroscopy_Computation_and_Ion_Sensing/5976880
A new
series of conjugated donor−π–acceptor
type of 2,6-bis(pyrazolyl)pyridine derivatives (compounds <b>IK-(3–9)</b>) 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 <b>IK-2</b>, one of the
starting precursors, and molecule <b>IK-3</b>, the first member
of the donor−π–acceptor series, are additionally
characterized by single-crystal X-ray structure determination. Compounds <b>IK-2</b> and <b>IK-3</b> are crystallized in <i>P</i>1̅ (triclinic) and <i>P</i>2<sub>1</sub>/<i>c</i> (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 <b>IK-7</b>. The role of the position and nature
of the donor functionalities in the conjugated backbone of overall
donor moiety of compounds <b>IK-(3–9)</b>, 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 <b>IK-3</b>, <b>IK-5</b>, and <b>IK-7</b> 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 <b>IK-4</b>) in the title
series has been shown to act as a selective molecular sensor (turn-off
switch) for the Cu(II) ion.