文章基本信息

标题：Synthesis, TD-DFT, and optical properties study of a chromeno-quinoline (acceptor) and mirror-less laser action enabled by energy transfer from a conjugated-polymer (Donor)
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作者：Saradh Prasad ; Mohamad S. Alsalhi ; Raju Suresh Kumar 等
期刊名称：Journal of King Saud University - Science
印刷版ISSN：1018-3647
出版年度：2022
卷号：34
期号：7
页码：1-9
DOI：10.1016/j.jksus.2022.102260
语种：English
出版社：Elsevier
摘要：Graphical abstractDisplay OmittedAbstractStructurally interesting chromeno-quinolines were constructed via the cyclization reaction of O-propargylated naphthaldehyde and substituted anilines in good yields. We explored compound methyl-chromenoquinoline (MCQ) in detail for its optical properties using Time-dependent density-functional theory (TD-DFT) and experimental studies. The conjugated-polymer (CP) Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(2,5-p-xylene)] or [(ADS145UV or PFOPX)] was studied as donor. The TD-DFT implied that MCQ is a fluorescent compound with well-defined highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) structure at −5.327 eV and −1.836 eV, respectively, with an energy gap of 3.49 eV in toluene captivity. The TD-DFT-based model and experimental study showed an energy gap of 3.326 eV and 3.351 eV, respectively, and the deviation was 0.025 eV. The experimental studies of MCQ showed solvent-dependent fluorescence peak shifted from 445 ± 2 nm to 538 ± 2 nm for dielectric constant ranging from 0.01 (hexane) to 10.2 (water). Despite the good optical properties, MCQ produced a weak laser-induced fluorescence (LIF) and not produce amplified spontaneous emission (ASE) to any pump energy of 3rd harmonic from Nd:YAG laser (5 ns, 355 nm). When PFOPX of concentration 500 nM (500 μL) was added to MCQ of 506 mM (3.5 mL) concentration, the LIF suddenly improved tenfold due to efficient Fluorescence resonance energy transfer (FRET) process. At the optimal concentration of PFOPX (670 nM) in MCQ solution, the spectrum changed dramatically. The spectrum has five peaks with a LIF in the background, where peaks around 393.5 nm and 417.3 nm attribute to the oligomer; 438.7 nm attributed to a combined fluorescence of PFOPX and MCQ; 466.4 nm, and 493.1 nm corresponding to MCQ. Analysis shows that the peaks at 440 nm (partly) and 493 nm were ASE from MCQ.
关键词：KeywordsChromenoquinolinesMCQPFOPXEnergy transferFRETASE