Synthesis, characterization and band gap energy of new water soluble fluorescent diethanolamine-boron-subphthalocyanine dye using B nanoparticles and SiB6 microparticles

Abstract

In the present work, the novel synthesis methods were developed for the preparation of a new water soluble and fluorescent diethanolamine-boron-subphthalocyanine (Dea-B-SubPc) dye. The boron nanoparticles and SiB6 were utilized as the boron sources for the Dea-B-SubPc synthesis. In order to obtain the boron nanoparticles, the powder mixture of boron microparticles, phthalonitrile (Pn) and KCl was encapsulated into a Cu pipe and then mechanically roll-milled at room-temperature. The Dea-B-SubPc dye was synthesized via the reaction of the roll-milled boron nanoparticles and Pn in 50 % Dea-toluene solution at 120 °C. The Dea-B-SubPc was also synthesized by the reaction of Pn and SiB6 microparticles using similar experimental conditions. The prepared Dea-B-SubPc was characterized by using the SEM, FT-IR, NMR, HR-ESI-MS, cyclic voltammetry (CV), UV–vis. absorption and fluorescence (FL) emission spectroscopy. The Dea-B-SubPc is soluble in H2O, DMSO, MeOH and EtOH solvents. The optical band gap energy of the Dea-B-SubPc was found as 2.15 eV in MeOH and H2O, and 2.10 eV in DMSO. The Dea-B-SubPc solutions exhibited FL emissions at 592.2 nm in DMSO, 575.2 nm in MeOH and 577.8 nm in H2O with the excitation at 450 nm. The EHOMO and ELUMO energy levels of the Dea-B-SubPc were calculated as −5.82 eV and −4.08 eV, respectively and then the electrochemical band gap energy was found as 1.74 eV using the CV measurements. In summary, both the B nanoparticles and SiB6 microparticles were used successfully for the synthesis of the Dea-B-SubPc as a new fluorescent and low band gap energy dye material.