Synthesis of Organoboron Quinoline-8-thiolate and Quinoline-8-selenolate Complexes and Their Incorporation into the π-Conjugated Polymer Main-Chain

Abstract

Low-molecular-mass organoboron quinoline-8-thiolate and -selenolate complexes as model compounds, and organoboron polymers incorporated their complex structures into the poly(p-phenylene-ethynylene) main chain were prepared. Tetracoordination states of boron atoms in the obtained compounds were confirmed by 11 B NMR spectroscopy, and the detailed structures of the model compounds were determined by singlecrystal X-ray diffraction analysis. The polymers were synthesized by Sonogashira-Hagihara coupling reaction of organoboron quinolate-based monomers having diiodo groups with 1,4-diethynylbenzene derivatives bearing electron-donating or -withdrawing groups in moderate yields. Their optical properties were studied by UV-vis absorption and photoluminescence spectroscopies. Increasing atomic number of the 16 Group atom adjacent to the boron atom caused emission shift to longer wavelength and decreasing of absolute quantum yields for both the model compounds and the polymers. There are no differences between the polymers with the donating π-conjugated linker and with the accepting one in the photoluminescence property, resulting from efficient energy transfer from π-conjugated main chain to Q ligand. Furthermore, the obtained polymers showed high refractive indices (n d > 1.66).

Photoluminescent Color and Polarized Light Emission Tuning of Fluorene Derivatives Using a Photoreactive H‐Bonded Liquid Crystalline Polymer

“…[1][2][3][4][5][6][7][8][9][10] Furthermore, polarized light emission is a key issue for backlighting liquid crystal displays (LCDs) and polarized luminescent devices. [11][12][13][14][15][16] Various types of monomeric and polymeric p-conjugated materials, including quinoline, phenylene-ethynylene, anthracene, and fluorene (FL) derivatives, have been synthesized due to their high photoluminescence (PL) and thermal stability.…”

“…Although introducing p-conjugated linkages controls the photoluminescent properties of a material, including PL wavelength, a synthetic modification is required. [2][3][4][5][6][7][8][9] Alternatively, hydrogen (H)-bonding or protonation using a proton-donating material varies the electrooptical properties of p-conjugated materials when the light-emitting moiety contains basic nitrogen (N) atoms; thus, synthetic modification is not required to control the optical properties. [17] Thus, the H-bonding or protonation technique allows the electrophysical properties of basic Ncontaining photoluminescent materials to be tuned by adjusting the acidity of the proton-donating material.…”

Synthesis of an E-BODIPY based fluorescent Co-polymer containing organoboron quinolate units

“…The energy transfer efficiency was found to be 99.6% which explains the efficient quenching of quinolate fluorescence. This novel donor-acceptor polymeric system shows superior properties such as high fluorescence quantum yield, high energy transfer efficiency and absorption in a wide spectral range, compared with other organoboron quinolate polymers [32][33][34][35]. The fluorescence quantum yield of the polymer is also higher than other BODIPY based conjugated polymers [10,[27][28][29].…”

“…In all known organoboron quinolate polymers, the quinolate ligand is the acceptor while the aromatic π-conjugated main chain is the donor [32][33][34][35]. Because quinolates absorb and emit at higher energy in comparison with BODIPY, we reasoned that a co-polymer of an organoboron quinolate and E-BODIPY would produce a new polymer where quinolate is the donor and the E-BODIPY is the acceptor.…”

Recent Advances in the Synthesis and Applications of Organoborane Polymers

“…Transition metal-catalyzed C-C coupling processes have also attracted increased attention. They have been widely used to incorporate luminescent BODIPY and boron 8-hydroxyquinolate heterocycles into conjugated polymers [94][95][96][97][98][99][100][101]. In addition, Sonogashira-Hagihara coupling was used to embed bis(borabenzene)iron complexes into conjugated polymers (24, Scheme 5c), while a recent report details the Stille-type polymerization of thiophene derivatives of diboraanthracene [102].…”