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A simple and efficient route to luminescent imidazo[1,2- a ]pyridines from 2-aminopyridines, phenylacetylene and arylaldehydes was achieved by an one-pot, tandem process starting with an A3-coupling followed by 5-exo-dig cyclization. Copper(II)oxide/copper aluminate composite (5 wt% CuO–CuAl 2 O 4 composite) and d -glucose catalyzed optimal conditions for the reaction were established after examining various reaction parameters such as solvent, catalyst and temperature. The synthesis was much compatible with various functionalities. 2-Aryl-imidazo[1,2- a ]pyridines not capable of excited state intramolecular proton transfer emission displayed moderate fluorescence quantum yields in the blue-green region due to intramolecular charge transfer process. In addition, they exhibited peculiar solvatochromic behaviour in chlorinated solvents like chloroform and dichloromethane. Products containing 2-(2′-hydroxyphenyl) substituent underwent excited state intramolecular proton transfer in non polar and polar-aprotic solvents. Although such type of emission in solvents was very weak, the Stokes shifts values were high (14,638–11,448 cm −1 ) with strong solid-state emission in green to yellow region. [ABSTRACT FROM AUTHOR]

• We have synthesized a novel compound,5-(1H-pyrrol-2yl)-7, 8, 13, 14-tetrahydrodibenzo [a, i] phenanthridine. • It detects Al3+, Th4+ and picric acid in ACN/Water medium through ratiometric fluorescence. • The limit of detection (LOD) values are 11.37 nM and 12.5 nM and 0.53 nM for Al3+, Th4+ and picric acid respectively. The ratiometric fluorescence sensor of 5-(1H-pyrrol-2yl)-7, 8, 13, 14-tetrahydrodibenzo [a,i]phenanthridine (4a), a ligand with blue emission, was introduced for the quantitative recognition of Al3+ and Th4+ ions and picric acid using absorption and emission spectroscopic techniques. We investigated the unique recognition of Al3+ and Th4+ ions and picric acid by 4a using the studies of UV–vis absorption and fluorescence spectroscopy in acetonitrile as solvent. There was a marked color change from blue to green at 365 nm UV light. High binding constant values (Ka) of 1.175 × 107 M−1 for Al3+ ions and of 3.233 × 106 M−1 for Th4+ ions, 4.3093 × 104 M−1 for picricacid respectively were exhibited by the sensor 4a. The interference studies showed the existence of high selectivity and sensitivity for the probe 4a towards Al3+ and Th4+ ions over other competing cations. Ligand 4a interacted with Al3+ and Th4+ ions to create a 1 : 1 complex, and 1H NMR titration and Job's plot studies confirmed this mechanism further. The sensor 4a had many advantages like low detection limits (LOD) of 38.7 nM and 70.5 nM and 0.53 nM towards Al3+ and Th4+ ions, picricacid and fast reaction. The sensing can be carried out in a wide pH range of 3 to 11. The real time application of 4a was effectively verified by the determination of Al3+ and Th4+ ions and picricacid in paper strips test and also in different water samples. [ABSTRACT FROM AUTHOR]

A series of 1-((2-hydroxynaphthalen-1-yl)(phenyl)(methyl))pyrrolidin-2-one derivatives by an efficient iodine catalyzed domino reaction involving various aromatic aldehydes, 2-pyrrolidinone and β-naphthol was achieved and the structures were elucidated by FTIR 1 H NMR, 13 C NMR, and HRMS. Subsequently they were evaluated for cytotoxicity against breast cancer (MCF-7), colon cancer (HCT116) cell lines. In the cytotoxicity, the relative inhibition activity was remarkably found to be high in MCF-7 cell lines as 79% ( 4c ), 83% ( 4f ) and the IC 50 values were 1.03 µM ( 4c ), 0.98 µM ( 4f ). Compounds 4a , 4e , 4k – m , and 4q were found to be inactive and rest showed a moderate activity. In order to get more insight into the binding mode and inhibitor binding affinity, compounds ( 4a – q ) were docked into the active site phosphoinositide 3-kinase (PI3K) (PDB ID: 4JPS) which is a crucial regulator of apoptosis or programmed cell death. Results suggested that the hydrophobic interactions in the binding pockets of PI3K exploited affinity of the most favourable binding ligands ( 4c and 4f : inhibitory constant ( ki ) = 66.22 nM and 107.39 nM). The SAR studies demonstrated that the most potent compounds are 4c and 4f and can be developed into precise PI3K inhibitors with the capability to treat various cancers. [ABSTRACT FROM AUTHOR]

This paper presents a methodology of oxidative cascade cyclisation of 2-aminobenzoic acids and arylaldehyde using I 2 as a catalyst and an environmentally benign oxidant oxone. This method displays facile access to a diverse range of substituted aryl 4H-3,1-benzoxazin-4-ones. This synthetic methodology has many advantages such as: (1) easy availability of starting material, (2) transition metal-free condition (3) use of an environmentally benign oxidant. [ABSTRACT FROM AUTHOR]

This paper primarily deals with the development of highly efficient phosphorescent iridium (III) complex based on benzoimidazophenanthridine as main ligand. The potential of this complex, as phosphorescent emitter for optoelectronic applications, was screened by different methods, including luminescence spectrometry, cyclic voltammetry, thermogravimetric analysis, differential scanning calorimetry as well as photoelectron emission spectrometry. The possible application of the developed complex in single-colour vacuum-deposited organic light emitting diodes (OLEDs) exhibiting warm orange electrophosphorescence was demonstrated. The device was characterized with CIE1931 colour coordinates of (0.539, 0.459), colour temperature of 2088 K and maximum external quantum efficiency of 17.5%. Good performance in OLEDs can be partly explained by efficient orange phosphorescence with quantum yield of 60% at room temperature. This paper also deals with the development of white hybrid solution-processable organic light-emitting devices, exploiting ultralow concentration of newly synthesized iridium (III) complex as phosphorescent dopant in combination with blue fluorescencent emitter(host), and green emitter exhibiting thermally activated delayed fluorescence emitter. It was designed and fabricated by spin coating white hybrid devices, and was characterized by high quality (human-eyes-friendly) electroluminescence achieving CIE1931 coordinates of (0.335, 0.392), colour temperature of 2910 K and colour rendering index of 72 as well as high maximum external quantum efficiency of 8.7%. Image 1 • The solutions of iridium(III) complex showed PLQY of up to 60%. • The complex was utilized for solution processable hybrid OLEDs. • White electroluminescence with color temperature of 2910 K was observed. [ABSTRACT FROM AUTHOR]