Synthesis and photophysical properties of tricyclic boron compounds. Experimental and theoretical study

The one pot reaction of 5-formyl-2-furanboronic acid, arylamines and aminophenol derivatives offered tricyclic boronates formation through the opening furan ring process. All seven synthesized compounds showed colorimetric properties when solved in different organic solvents, the solvatochromic effect was denoted by naked-eye as well as from the UV–vis spectra. Compounds also showed to be fluorescence under UV irradiation to 365 nm. DFT theoretical calculations showed that for structures having a major π conjugation extension, the energic difference between the HOMO – LUMO levels decrease. Thus, pyrene and anthracene derivatives showed a smaller band gap energy than phenyl derivatives, which is associate with the experimental observation of the blue-shift detected in either absorption or emission bands for aniline derivatives.