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The pyridine substituted thiourea derivative PTB-1 was synthesized and characterized by spectroscopic techniques as well as by single crystal X-ray crystallography. The metal ion sensing ability of PTB-1 was explored by various experimental (naked-eye, UV-Vis, fluorescence, mass spectrometry and 1H NMR spectroscopy) and theoretical (B3LYP/6-31G**/LANL2DZ) methods. PTB-1 exhibited a highly selective naked-eye detectable color change from colorless to dark brown and UV-Vis spectral changes for the detection of Ag+ with a detection limit of 3.67 μM in aqueous medium. The detection of Ag+ ions was achieved by test paper strip and supported silica methods. In contrast, PTB-1 exhibited a 23-fold enhanced emission at 420 nm in the presence of Hg2+ ions with a nano-molar detection limit of 0.69 nM. Finally, the sensor PTB-1 was applied successfully for the intracellular detection of Hg2+ ions in a HepG2 liver cell line, which was monitored by the use of confocal imaging techniques.

The detection of intracellular fluoride was achieved by a novel Schiff base chemosensor derived from vitamin B6 cofactor (L) using fluorescence imaging technique. The sensor L was synthesized by condensation of pyridoxal phosphate with 2-aminothiophenol. The anion recognition ability of L was explored by UV–Vis and fluorescence methods in DMSO and mixed DMSO-H2O system. The sensor L showed both naked-eye detectable color change from colorless to light green and remarkable fluorescence enhancement at 500 nm in the presence of F− and AcO−. The anion recognition was occurred through the formation of hydrogen bonded complexes between these anions and L, followed by the partial deprotonation of L. The detection limit of L for the analysis of F− and AcO− was calculated to be 1.88 μM and 9.10 μM, respectively. Finally, the detection of cytoplasmic fluoride was tested using human cancer cell HeLa through fluorescence imaging.

A simple uracil nitroso amine based colorimetric chemosensor (UNA-1) has been synthesized and screened for its cation recognition ability. Sensor UNA-1 exhibited a high sensitivity and selectivity towards Cu2+ ions in aqueous medium in the presence of a wide range of other competing cations (Ag+, Al3+, Ba2+, Ca2+, Cd2+, Co2+, Cr3+, Cs+, Fe2+, Fe3+, Li+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, Zn2+, Hg2+ and Sr2+). With Cu2+, the sensor UNA-1 gave a distinct color change from colorless to dark yellow by forming a complex of 1 : 1 stoichiometry. Furthermore, sensor UNA-1 was successfully utilized in the preparation of test strips and supported silica for the detection of Cu2+ ions from aqueous environment.

The pyridine substituted thiourea derivative PTB-1 was synthesized and characterized by spectroscopic techniques as well as by single crystal X-ray crystallography. The metal ion sensing ability of PTB-1 was explored by various experimental (naked-eye, UV-Vis, fluorescence, mass spectrometry and

An electronically active and spectral sensitive fluorescent "turn-on" chemosensor (BTP-1) based on the benzo-thiazolo-pyrimidine unit was designed and synthesized for the highly selective and sensitive detection of Fe3+ from aqueous medium. With Fe3+, the sensor BTP-1 showed a remarkable fluorescence enhancement at 554 nm (lambda(ex) = 314 nm) due to the inhibition of photo-induced electron transfer. The sensor formed a host-guest complex in 1:1 stoichiometry with the detection limit down to 0.74 nM. Further, the sensor was successfully utilized for the qualitative and quantitative intracellular detection of Fe3+ in two liver cell lines i.e., HepG2 cells (human hepatocellular liver carcinoma cell line) and HL-7701 cells (human normal liver cell line) by a confocal imaging technique. (C) 2014 Elsevier B.V. All rights reserved.

The anion recognition ability of a novel azo dye derived from 4-hydroxycuomarin (L) was investigated by experimental (UV–vis, fluorescence and 1H NMR) and theoretical [(B3LYP/6-31G(d,p)] methods. Among the surveyed anions, the receptor L showed both naked-eye detectable color and spectral changes in the presence of F−, AcO− and H2PO4− due to the formation of hydrogen bonding complexes followed by deprotonation between these anions and L.

A new phthalimide based chemosensor 2-(Pyridin-2-yl-(pyridine-2-ylimino)methyl)isoindoline-1,3-dione (PP3) was synthesized and characterized by IR, LCMS and NMR spectroscopic methods. The metal ions sensing ability of PP3 was examined by naked-eye and UV–Vis absorption techniques. The colorless solution of PP3 turned to yellow upon addition of Cu2+ and a new absorption band appeared at 434 nm. The Job's plot and HR-MS data confirms the formation of a new complex species between PP3 and Cu2+ in 1:1 binding stoichiometry. The sensor PP3 allowed the detection of Cu2+ down to 1.65 μM without any remarkable interference from the other tested metal cations.

A Zn-exchanged heteropolyacid supported onto silica (Zn-HPW/SiO2) activates methane at 25 °C into Zn-methyl. At higher temperatures and with CH4/O2 or CH4/CO2, it gives methanol and acetic acid respectively.

A novel Schiff base receptor (L) bearing catechol and phenol groups was synthesized and characterized by various spectral (FTIR, 1H NMR and mass) data. The anion recognition ability of L was investigated by experimental (UV-Vis, fluorescence and 1H NMR) and theoretical (B3LYP/6-31G**) methods. Among the tested anions, the receptor L showed both naked-eye detectable color change from light-yellow to intense brownish-yellow and spectral (hyperchromic shift at 450 nm and ‘turn-on’ fluorescence at 480 nm) changes selectively towards F− and AcO− in DMSO and mixed DMSO–H2O medium because of the formation of a hydrogen bonded anion-receptor complex followed by the deprotonation of L. The receptor L was tested for live breast cancer cell imaging and can be applied to the breast tumour diagnosis.

An imatinib intermediate, 6-methyl-N-[4-(pyridin-3-yl)pyrimidin-2-yl]benzene-1,3-diaminepyridopyrimidotoluidine (PPT-1), was developed for the colorimetric sensing of Cu2+ ions in aqueous solution. With Cu2+, the receptor PPT-1 showed a highly selective naked-eye detectable color change from colorless to red over the seventy other tested cations. The colorimetric sensing ability of PPT-1 was successfully utilized in the preparation of test strips and supported silica for the real samples analysis to detect Cu2+ ions from 100% aqueous environment. Moreover, the iodide-sensing ability of receptor PPT-1 was explored among the ten examined anions.

A pyridine based imine-linked chemosensor has been synthesized and evaluated its binding affinity with library of transition metal ions. It has prominent selectivity towards Pb2+ among other metal ions in DMF/H2O (9:1, v/v) solvent system. The 1:1 stoichiometric was confirmed by job’s plot and has a binding constant (Ka) = 5.142 × 103 M−1 on fluorescence. A B3LYP/6-31G and B3LYP/LanL2DZ basis sets were employed for optimization of 3 and 3.Pb2+.

Aim: Synthesis of some novel formazan derivatives from condensation of aniline diazo-nium salt with a variety of Schiff bases of 3,4-dimethyl-1H-pyrrole-2-carbohydrazidemoiety and evaluate their potential antimicrobial and antioxidant activities.Methods: Novel substituted formazans (2a-j) were prepared from Schiff bases of 3,4-dimethyl-1H-pyrrole-2-carbohydrazide (1a-j) by condensation with aniline diazoniumchloride in pyridine (Scheme 1). All the formazan derivatives were characterized by IR, 1 HNMR, 13 C NMR and Mass spectroscopy.Results: These molecules (2a-j) exhibits moderate to good antimicrobial and antioxidantactivities some of which are comparable to standards used in this study.Conclusion: The results of preliminary bioassays of derivatisation of Schiff bases to for-mazan indicate that a number of these molecules exhibits moderate to good antibacterial,antifungal and antioxidant activities some of which are comparable to standard used inthis study. The outcome indicates that there is a good scope for evaluation of this class ofcompounds as potential leads towards antimicrobial and antioxidant agents.Copyright a 2013, JPR Solutions; Published by Reed Elsevier India Pvt. Ltd. All rightsreserved.

We report a greener, economical, highly convenient and regioselective synthesis of (2E)-2-[2,3,6-arylpyrimidin-4(3H)-ylidene)acetonitriles derivatives 3. This is achieved by a strategy involving ring transformation reaction of 4-(methylthio)-2-oxo-6-aryl-2H-pyran-3-carbonitrile 1 with N-arylbenzamidine or N-arylpicolinamidine 2 in the presence of KOH/DMF catalyst at room temperature. This approach provides a one-pot approach for the synthesis of symmetrical, unsymmetrical and heteroaryl pyrimidin-4(3H)-ylidene)acetonitriles derivatives 3. Figure options Download full-size image Download as PowerPoint slide

A new, TiCl4-or SnCl4-mediated, solvent-free method was developed for the synthesis of N-Aryl benzamidines and N-phenylpicolinamidines, in moderate-to-good yield, using suitable amines and nitriles as starting materials.

The reaction in polyethylene glycol in the absence of any catalyst is a novel and eco-friendly method for the synthesis of pyridones.

An imatinib intermediate, 6-methyl-N-[4-(pyridin-3-yl)pyrimidin-2-yl]benzene-1,3-diaminepyridopyrimidotoluidine (PPT-1), was developed for the colorimetric sensing of Cu(2+) ions in aqueous solution. With Cu(2+), the receptor PPT-1 showed a highly selective naked-eye detectable color change from colorless to red over the seventy other tested cations. The colorimetric sensing ability of PPT-1 was successfully utilized in the preparation of test strips and supported silica for the real samples analysis to detect Cu(2+) ions from 100% aqueous environment. Moreover, the iodide-sensing ability of receptor PPT-1 was explored among the ten examined anions.

An amidine based chemosensor AM-1 was synthesized and characterized by various spectroscopic (FT-IR, (1)H-NMR and mass) data and elemental analyses. Sensor AM-1 exhibited high selectivity and sensitivity towards Fe(3+), Fe(2+) and Cu(2+) in the presence of other surveyed ions (such as Sr(2+), Cr(3+), Co(2+), Ni(2+), Zn(2+), Ag(+), Al(3+), Ba(2+), Ca(2+), Cd(2+), Cs(+), Hg(2+), K(+), Li(+), Mg(2+), Mn(2+), Na(+) and Pb(2+)) with a distinct naked-eye detectable color change and a shift in the absorption band. Moreover, the emission of AM-1 was quenched selectively only in the presence of Fe(3+).

12 Title compounds of type (III), (V), or (VII) are prepared by a ring transformation reaction via a two-carbon insertion from 2-acetylpyridine (II).

Herein, we present an innovative, novel, and highly convenient protocol for the synthesis of 3-(pyridin-2-yl)-5-sec-aminobiphenyl-4-carbonitriles (6a, 6b, 6c, 6d, 6e, 6f, 6g) and 9,10-dihydro-3-(pyridine-2-yl)-1-sec-aminophenanthrene-2-carbonitriles (10a, 10b, 10c, 10d, 10e), which have been delineated from the reaction of 4-sec-amino-2-oxo-6-aryl-2H-pyran-3-carbonitrile (4a, 4b, 4c, 4d, 4e, 4f, 4g) and 4-sec-amino-2-oxo-5,6-dihydro-2H-benzo[h]chromene-3-carbonitriles (9a, 9b, 9c, 9d, 9e) with 2-acetylpyridine (5) through the ring transformation reaction by using KOH/DMF system at RT. The salient feature of this procedure is to provide a transition metal-free route for the synthesis of asymmetrical 1,3-teraryls like 3-(pyridin-2-yl)-5-sec-aminobiphenyl-4-carbonitriles (6a, 6b, 6c, 6d, 6e, 6f, 6g) and 9,10-dihydro-3-(pyridine-2-yl)-1-sec-aminophenanthrene-2-carbonitriles (10a, 10b, 10c, 10d, 10e). The novelty of the reaction lies in the creation of an aromatic ring from 2H-pyran-2-ones and 2H-benzo[h]chromene-3-carbonitriles via two-carbon insertion from 2-acetylpyridine (5) used as a source of carbanion.

A pyridine based imine-linked chemosensor has been synthesized and evaluated its binding affinity with library of transition metal ions. It has prominent selectivity towards Pb

We report a greener, economical, highly convenient and regioselective synthesis of (2E)-2-[2,3,6-arylpyrimidin-4(3H)-ylidene)acetonitriles derivatives 3. This is achieved by a strategy involving ring transformation reaction of 4-(methylthio)-2-oxo-6-aryl-2H-pyran-3-carbonitrile 1 with N-arylbenzamidine or N-arylpicolinamidine 2 in the presence of KOH/DMF catalyst at room temperature. This approach provides a one-pot approach for the synthesis of symmetrical, unsymmetrical and heteroaryl pyrimidin-4(3H)-ylidene)acetonitriles derivatives 3. Figure options Download full-size image Download as PowerPoint slide

The reaction in polyethylene glycol in the absence of any catalyst is a novel and eco-friendly method for the synthesis of pyridones.

The ring transformation of 2H-pyran-2-ones by N-aryl amidines is strongly influenced by the amidine substituents and leads to title compounds of type (III).

The ring transformation of 2H-pyran-2-ones by N-aryl amidines is strongly influenced by the amidine substituents and leads to title compounds of type (III).

A facile one-pot method to prepare three-dimensional hierarchical nanostructures of titania with good control over their morphologies without the use of hydrofluoric acid is developed. The reaction is performed under microwave irradiation conditions in pure water, and enables enhanced photocatalytic activity. This study indicates that photocatalytic activity depends not only on the surface area but also on the morphology of the titania.

We report the use of silicon oxynitrides as novel adsorbents for CO2 capture. Three series of functionalized materials based on KCC-1, SBA-15 and MCM-41 with Si–NH2 groups were prepared using a simple one-step process via thermal ammonolysis using ammonia gas, and they demonstrated excellent CO2 capture capabilities. These materials overcome several limitations of conventional amine-grafted mesoporous silica. They offer good CO2 capture capacity, faster adsorption–desorption kinetics, efficient regeneration and reuse, more crucially excellent thermal and mechanical stability even in oxidative environments, and a clean and green synthesis route, which allows the overall CO2 capture process to be practical and sustainable.