Graphene Oxide-terpyridine Conjugate: A Highly Selective Colorimetric and Sensitive Fluorescence Nano-chemosensor for Fe2+ in Aqueous Media

A graphene oxide-terpyridine conjugate (GOTC) based colorimetric and fluorescent nano-chemosensor was synthesized. It showed high selectivity and sensitivity for Fe2+ and Fe3+ ions in neutral aqueous solution over other metal ions such as Li+, Na+, Ba2+, Ca2+, Al3+, Cd2+, Co2+, Cu2+, Hg2+, Mn2+, Ni2+, Pb2+, Zn2+, Cr3+ and Ag+. In absorption spectra, upon addition of Fe2+ or Fe3+, the sensor displayed a peak at 568 nm, by changing the color of the solution from light pink for GOTC to light magenta and deep magenta for Fe3+ and Fe2+, respectively. Also, the fluorescence studies revealed that, Fe2+, Fe3+ and Co2+ quench the emission of GOTC at 473 nm, while other metal ions do not quench the fluorescence of GOTC in solution. Colorimetric and fluorescence techniques could be used for detection of Fe2+ ion concentration at least about 6-10 μM in water solution. The sensing on test paper was also investigated for the naked-eye detection of Fe2+

Ultrasound-assisted green synthesis of pyrroles and pyridazines in water via three-component condensation reactions of arylglyoxals

A green and efficient method for the preparation of 5-aryl-4-hydroxy-2-methyl-1H-pyrrole-3-carboxylic acid esters and 6-aryl-3-methylpyridazine-4-carboxylic acid esters via three-component reaction of arylglyoxal hydrates with β-dicarbonyl compounds in the presence of ammonium acetate and hydrazine hydrate using water as solvent under ultrasonic irradiation was reported. The reactions proceeded rapidly and afforded the corresponding pyrroles and pyridazines in good to high yields in very short reaction time

Chemistry of α‑Oxoesters: A Powerful Tool for the Synthesis of Heterocycles

Chemistry of α‑Oxoesters: A Powerful Tool for the Synthesis of Heterocycle

2-[Anilino(phenyl)methyl]cycloheptanone

In the title compound, C20H23NO, the cycloheptanone ring adopts a twist-chair conformation, with the aminomethyl substituent in an equatorial position. The relative configuration of the two stereocenters is R,R. In the crystal, molecules are linked by N—H...O hydrogen bonds into chains along [100]