Main-chain-type N,N′-chelate organoboron ammoquinolate polymers:: Synthesis, luminescence, and energy transfer behavior

A novel green luminescent compound, (k(2)-(N,N')-8-acetylaminoquinolate)diphenylborane (1) was synthesized and fully characterized. To incorporate into the polymer main-chain, (k(2)-(N,N')-8-acetylaminoquinolate)bis(4-iodophenyl)borane was also synthesized as a monomer. A new class of fluorescent main-chain type organoboron aminoquinolate polymers were prepared by means of the Sonogashira-Hagihara coupling reaction between diyne monomers and the aminoquinoline monomer. The obtained polymers were further investigated by UV-vis absorption and fluorescence spectroscopy. It was revealed that the fluorescent quantum efficiencies of the obtained polymers depended on the pi-conjugated linker unit. In addition, an efficient energy transfer was observed and well pi-extended linker units played a role in a light harvesting antenna for the organoboron aminoquinolate units.