Synthesis And Properties Of Organic Boronic Acid Compounds Containing Schiff Base Structure

In this article, we have synthesized the 3-aminophenylboronic acid Schiff base and derivatives and introduced the structure and the properties of these material.Using 5-nitrosaicylaldehyde and 3-aminophenylboronic acid got 3-[(2-hydroxy-5-nitrophenyl)methylene] aminophenylboronic acid (compound 1). Compound 1 and diethanolamine were reactioned to get a 3-[(2-hydroxy-5-nitrophenyl)methylene]aminophenylboronic-diethanolamine ester compound (2). Characterization of Compound 1 and 2 have tested through infrared spectrum, element analysis, and hydrogen nuclear magnetic spectra, and the crystal structure of 2 aslo have tested. Single crystal structure analysis showed that the crystal belongs to tetragonal crystal system, Pca21 space group.1 A of the crystal cell parameters:a= 19.5516(19) A, b= 4.8474(5) A, c= 19.3396(19) A, a= 90.00 °,β= 90.00(2)°,γ= 90.00°, Z= 4, F(000)= 824.0, R1=0.0525, wR2= 0.0849. With compound 1+ARS, compound 2+ARS as the research system, their fluorescent properties were measured. Test condition of compounds 1+ARS system:the concentration of the compounds 1 is 3×10-2mol/L, the concentration of the ARS is 7×10-4 mol/L, all the solvent is DMF. With the increase of compound 1 in the system, the fluorescence intensity of the system is increased, showed that compound 1 have free boric acid groups. Test condition of compounds 2+ARS system:the concentration of the compound 2 is 3 ×10=2 mol/L, the concentration of the concentration of the ARS is 7×10-4 mol/L, all the solvent is DMF. Results show that with the increase of compound 2, the fluorescence intensity of the system has no obvious change, this shows that compound 2 doesn’t have free boric acid group.In this article, we have carried on the theoretical calculation of the similar structure compared with the compound 1, and have studied the electron density, orbital energy, etc.This paper, by using Pyridine-2-carboxaldehyde and 3-aminophenylboronic acid to obtain 3-[(2-pyridine)methylene] aminophenylboronic acid (compound 3). By using compound 3 and salicylaldehyde shrinkage ethanol amine Schiff base to obtain compound 4, and salicylaldehyde shrinkage isopropyl alcohol amine Schiff base to obtain compound 5 respectively. And studied the compounds.