A New Azo-Schiff Base Dual-mode Chemosensor: Colorimetric Detection of Cobalt Ions and Fluorometric Detection of Aluminum Ions in Aqueous Ethanol Solution.

A new Azo-Schiff base ligand (H2L) was designed and synthesized as a cation chemosensor. The chemosensor H2L as dual chemosensor showed selective fluorescence recognition of Al3+ with a noticeable fluorescence enhancement and colorimetric detection of Co2 + in aqueous ethanol solution. The H2L exhibits a linear response toward Al3+ ions in the concentration range of 1.91 × 10-8 M to 4.8 × 10-6 M with a limit of detection of 1.91 × 10-8 M. The sensing mechanism of sensor H2L toward Al3+ was investigated by 1H NMR and IR spectroscopies. Fluorescence switch based on the control of EDTA and Al3+ proved H2L could act as a reversible chemosensor. The molecular structure of [NiL] complex has been determined by X-ray crystallography.

Ni-citric acid coordination polymer as a practical catalyst for multicomponent reactions.

Coordinative polymers (CP) are a subclass of Metal-organic frameworks (MOFs) with porous microstructures which have been widely synthesized in recent years and applied in various fields especially in catalysis science. In this work Coordinative polymers (CP) of nickel and citric acid (CA) was prepared as a new catalyst (Ni-CP) and applied in organic multicomponent reactions. The obtained catalyst was characterized by SEM, WDX, EDS, AAS, FT-IR, XRD and BET analysis. N2 adsorption-desorption isotherms indicate good BET surface area for Ni-CP; therefore can be employed as an efficient catalyst in multicomponent reactions for the synthesis of polyhydroquinoline and 2,3-dihydroquinazolin-4(1H)-one derivatives. Finally, this catalyst was recovered and reused several consecutive times.