A fluorescent probe of N'-formyl-rhodamine B hydrazide: structure and spectral properties of protonation behaviour.

The title compound is an "off-on" rhodamine probe. It exhibits strong pH dependence and responds to protons. The optimized geometries and energies calculation of the protonation were determined at the B3LYP level using DFT.

Efficient and selective conversion of sucrose to 5-hydroxymethylfurfural promoted by ammonium halides under mild conditions.

The highly efficient and selective production of 5-hydroxymethylfurfural (HMF) from sucrose has been achieved in the presence of metal chlorides and ammonium halides under mild conditions. Notably, an 87% yield of HMF from sucrose was obtained with a catalyst system composed of CrCl(3) and NH(4)Br at 100°C for 1.0 h in N,N-dimethylacetamide (DMAc) solvent.

A theoretical study of imine-ene reaction influencing factors.

Potential energy surfaces of the imine-ene reaction between methanimine and propene have been calculated using restricted and unrestricted density functional theory at the B3LYP level. The results show that a concerted mechanism with an exo configuration for lone pair electrons transition structure is more favourable for the intermolecular bare imine-ene reaction. In addition, the C-C bond formation and the migration of the propene α-hydrogen occur simultaneously.