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Development of Pyrene Embedded Luminophore via π‐linker: Room Temperature Phosphorescence (RTP) and Sensing towards Nitroaromatics (NACs)

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Kannan Jamuna
Kannan Jamuna
Kannan Jamuna
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Prasannamani Govindharaj at Lodz University of Technology
Prasannamani Govindharaj
Aravind Krishnan
Aravind Krishnan
Aravind Krishnan
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Savitha Devi Natarajan at Arul Anandar College
Savitha Devi Natarajan
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Abstract and Figures

A pyrene base luminophore was designed and synthesised under ambient conditions using [4+2] annulation. The synthesised probe PYINDP exhibits good optical properties and emits greenish blue, with high colour purity in solid, solution, and thin film phases. In solution, the CIE coordinates were found to be (0.20, 0.48), and for an aggregated state emitting deep green colour, the CIE values are (0.27, 0.65). Room temperature phosphorescence (RTP) is generated by the luminophore PYINDP, owing to the ISC process. Moreover, the emitter demonstrated an excellent limit of detection values in detecting nitroaromatics (NACs). Bio‐imaging studies on HEK, A549 cell lines were successfully carried out to verify the staining capability of PYINDP in biological systems.
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Development of Pyrene Embedded Luminophore via π-
linker: Room Temperature Phosphorescence (RTP) and
Sensing towards Nitroaromatics (NACs)
Kannan Jamuna,[a, b] Prasannamani Govindharaj,[c] Aravind Krishnan,[d]
Natarajan Savitha Devi,[e] Amal Tom Sebastian,[b] Narayanan Selvapalam,[a]
Moubani Mukherjee,[b] Przemyslaw Data,*[c] Santhalingum Gayathri,[f]
Shanmugam Sivakumar,*[b] and Balasubramaniem Ashokkumar[f]
A pyrene base luminophore was designed and synthesised
under ambient conditions using [4 +2] annulation. The synthes-
ised probe PYINDP exhibits good optical properties and emits
greenish blue, with high colour purity in solid, solution, and
thin film phases. In solution, the CIE coordinates were found to
be (0.20, 0.48), and for an aggregated state emitting deep green
colour, the CIE values are (0.27, 0.65). Room temperature
phosphorescence (RTP) is generated by the luminophore
PYINDP, owing to the ISC process. Moreover, the emitter
demonstrated an excellent limit of detection values in detecting
nitroaromatics (NACs). Bio-imaging studies on HEK, A549 cell
lines were successfully carried out to verify the staining
capability of PYINDP in biological systems.
Introduction
Organic conjugated systems have gained extensive attention
recently due to their wide applications in electronic and
optoelectronic, biosensor, and bio-imaging fields.[1–4] Pyrene, as
a representative polyaromatic hydrocarbon, finds extensive
usage in various organic electronic devices, including OLEDs,[5–7]
OFETs,[8–11] solar cells,[12,13] and other organic
semiconductors,[14,15] owing to its deep blue fluorescence,
macrocyclic conjugation, and high charge carrier mobility.[16–18]
The pyrene moiety enables thermal and chemical stability and a
high photoluminescence quantum yield. However, its suitability
for efficient OLED applications is limited due to the quenching
of fluorescence efficiency caused by excimer formation.[19–22] In
the solid state, most pyrene systems exhibit weak or non-
fluorescent behaviour due to their extensive π-conjugation.
Researchers overcome this limitation by attaching bulky
substituents or spiro-type frameworks to the pyrene moiety to
inhibit π–πinteractions.[23,24] Researchers have extensively
studied the detection of harmful and toxic nitroaromatic
compounds (NACs) for a multitude of environmental and safety
purposes. NACs, which are primary constituents in many
explosives and widely used in industries such as rocket fuel,
dye, leather, pharmacology, and chemicals,[5,25–28] include several
substances recognized as harmful or carcinogenic. Among
them, picric acid (PA) contributes significantly to soil and water
pollution due to its high solubility in water.[29,30] Inhalation of PA
can cause various physiological problems, including skin
irritation, hepatic malfunction, and anaemia.[31–36] Therefore,
researchers find the convenient and sensitive detection of NACs
an appealing research topic.
Herein, we report the synthesis and structural elucidation of
a new pyrene moiety decorated with a phenanthridine scaffold.
The probe was synthesised via a novel [4 +2] annulation
strategy between oxoketene dithioacetals (3) and indenoquino-
line (4). The heterocyclic luminophore PYINDP has a nitrogen
atom favouring an n-π* transition and creating triplet-state
excitons, leading to room temperature phosphorescence (RTP)
through intersystem crossing (ISC) under ambient
conditions.[37,38] The optical properties of the compound were
comprehensively excavated employing density functional
theory (DFT) calculations. Additionally, the probe PYINDP can
detect nitroaromatic chemicals, such as 4-nitroaniline (NA), 2,6-
dinitroaniline (DNA), and picric acid (PA), through a FRET and
electrostatic interaction mechanism with high sensitivity.
[a] K. Jamuna, N. Selvapalam
Kalasalingam Academy of Research and Education, Krishnan Koil, Viruthu-
nagar-626126, India
[b] K. Jamuna, A. T. Sebastian, M. Mukherjee, S. Sivakumar
Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj
University, Madurai-625021, India
E-mail: sivakumar.chemistry@mkuniversity.ac.in
[c] P. Govindharaj, P. Data
Łódź University of Technology, Faculty of Chemistry, Department of
Molecular Physics, Stefana Żeromskiego 116, 90-924 Łódź, Poland
E-mail: przemyslaw.data@p.lodz.pl
[d] A. Krishnan
Department of Chemistry, Saint Berchmans College, 686101 Kottayam
Changanassery, Kerala, India
[e] N. Savitha Devi
Department of Chemistry Arul Anandar College Madurai-625514 Tamil
Nadu India
[f] S. Gayathri, B. Ashokkumar
School of Biotechnology Madurai Kamaraj University, Madurai-625021
Tamil Nadu India
Supporting information for this article is available on the WWW under
https://doi.org/10.1002/cptc.202400046
Wiley VCH Donnerstag, 07.11.2024
2411 / 367201 [S. 161/167] 1
ChemPhotoChem 2024,8, e202400046 (1 of 7) © 2024 Wiley-VCH GmbH
ChemPhotoChem
www.chemphotochem.org
Research Article
doi.org/10.1002/cptc.202400046
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