| Abstract
| - A series of stilbeneboronate pinacol cyclic esters, containing none to three nitro groups, have beensynthesized by various olefination reactions and characterized by X-ray single-crystal structure analysis.A stilbeneboronate ester bearing electron-acceptor groups experiences transition to a push−pull π-electronsystem upon complexation with one fluoride ion at the boron atom. The UV−vis absorption maxima ofthe presented nitro-substituted stilbeneboronate esters are red-shifted upon addition of fluoride ions,indicating this binding event. The enhancement of the polarity of the investigated compounds and thechanges in the electronic system were investigated by UV−vis absorption spectroscopy and solvatochromism. Additionally, studies were performed by natural bond orbital (NBO) analysis and RI-CC2calculations of the vertical excitation energies. The synergism of fluoride ion complexation and solvationupon the UV−vis band shift is interpreted in terms of linear solvation energy relationships (LSERs)using the Kamlet−Taft solvent parameter set. It is found that the UV−vis absorption of the fluoro-boronates is strongly dependent on the solvents hydrogen-bond donating ability.
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