Synthesis, X-ray diffraction analysis, and chemical-optical characterizations of boron complexes from bidentate ligands

摘要

Herein is reported the synthesis and X-ray diffraction analysis for three boron complexes (2a-2c) prepared from the reaction of bidentate ligands (1a-1c) and diphenylborinic acid. Chemical characterization for the borinates is completed with IR, UV-Vis and NMR techniques, particularly 11B NMR spectra confirmed the formation of boron complexes. X-ray diffraction analysis showed that for compounds 2a and 2c a non-planar conformation for the main π-backbone is acquired after boron complexation; for compound 2b the planar conformation is preserved. Additionally, cubic nonlinear optical (NLO) properties were evaluated, through the optical susceptibility χ ~((3)) (-3ω, ω, ω, ω), using the THG Maker-Fringes technique. Results showed that χ ~((3)) response decreases from ligands to boron complexes; this behavior could be attributed to a structural conformation or deformation of the electronic π-system after boron complexation. The demonstrated electronic and structural features of these borinates could be useful for new strategies in the design of novel NLO dyes.