Green synthesis of silver nanoparticles using Piper longum catkin extract irradiated by sunlight: antibacterial and catalytic activity

Research on Chemical Intermediates - In this study, rapid and cost-effective biosynthesis of silver nanoparticles (AgNPs) was synthesized by using Piper longum (P. longum) catkin extract. The...     

Ratiometric fluorescent chemosensor for silver ion at physiological pH

Bis-pyrene derivative 1, bearing two pyrene and pyridine groups, was synthesized as a ratiometric fluorescent chemosensor for Ag(+) in aqueous solution. Fluorescent chemosensor 1 displayed a selective ratiometric change with Ag(+), which was attributed to the excimer-monomer emissions of pyrenes. A mechanism for the binding mode was proposed based on fluorescence changes, NMR experiments, and theoretical calculations.     

A Novel Dimeric BINOL for Enantioselective Recognition of 1,2‐Amino Alcohols

A novel auxillary chiral dimeric binol has been designed, synthesized, and used to enantioselectively recognize 1,2‐amino alcohols through the three point of interactions, the reversible imine bond, resonance assisted hydrogen bonding and the hydrogen bonding by the additional chiral moiety introduced at the receptor. The enantioselectivities were comparable to those of the previous reported receptors.     

Reactive extraction of enantiomers of 1,2-amino alcohols via stereoselective thermodynamic and kinetic processes

(R)-amino alcohol with an enantiomeric excess of >95% was resolved by reactive extraction processes from 2 equiv of racemic alcohol using a chiral receptor 2 as an enantioselective extractant. One resolution cycle is composed of three extractions: a stereoselective reversible imine formation, a stereoselective irreversible imine hydrolysis, and the recovery of 2 and enantiomeric amino alcohols.