Abstract:Main‐chain boron‐containing π‐conjugated polymers are attractive for organic electronic, sensing, and imaging applications. Alternating terthiophene‐borane polymers were prepared and the effects of regioisomeric attachment of the conjugated linker and variations in the electronic effect of the pendent aryl groups (2,4,6‐tri‐tert‐butylphenyl, Mes*; 2,4,6‐tris(trifluoromethyl)phenyl, FMes) examined. Pd2dba3/P(t‐Bu)3‐catalyzed Stille polymerization of arylbis(2‐thienyl)borane and arylbis(3‐thienylborane) with 2,5… Show more
“…These results demonstrate that these bulky aryl groups on boron can have a significant impact on the optical properties of small p-π* conjugated compounds. Indeed, extended conjugated systems such as p-π* conjugated polymers exhibit relatively high Φ PL values . This suggests that the molecular orbitals of the bulky aryl group on boron are not involved in the fluorescence process of the extended p-π conjugated system.…”
Boron-doped π-conjugated materials have generated
interest
owing to their interesting photophysical properties derived from the
empty p-orbital on boron. In particular, the electron-accepting properties
of triarylborane units are useful for the development of electron-deficient
π-conjugated materials such as organic n-type semiconductors.
On the other hand, sulfones and sulfoxides are also electron-deficient
species that can be easily prepared by oxidation of the corresponding
sulfides. In this work, we prepared new thiophene-fused thiaborin
conjugated building blocks with different oxidation states of the
sulfur atom. The new building blocks possess distinct photophysical
properties that are dependent on the oxidation state of the sulfur
atom. In particular, the sulfone compound exhibits a LUMO energy level
that is markedly lower than those of the corresponding dithienylborane
and dithienylthiophene S,S-dioxide,
suggesting that the combination of boron and sulfone enhances the
electron-accepting properties. In addition, the sulfone unit can be
modified by the Stille cross-coupling reaction, demonstrating its
potential use in other functional p-π* conjugated materials.
“…These results demonstrate that these bulky aryl groups on boron can have a significant impact on the optical properties of small p-π* conjugated compounds. Indeed, extended conjugated systems such as p-π* conjugated polymers exhibit relatively high Φ PL values . This suggests that the molecular orbitals of the bulky aryl group on boron are not involved in the fluorescence process of the extended p-π conjugated system.…”
Boron-doped π-conjugated materials have generated
interest
owing to their interesting photophysical properties derived from the
empty p-orbital on boron. In particular, the electron-accepting properties
of triarylborane units are useful for the development of electron-deficient
π-conjugated materials such as organic n-type semiconductors.
On the other hand, sulfones and sulfoxides are also electron-deficient
species that can be easily prepared by oxidation of the corresponding
sulfides. In this work, we prepared new thiophene-fused thiaborin
conjugated building blocks with different oxidation states of the
sulfur atom. The new building blocks possess distinct photophysical
properties that are dependent on the oxidation state of the sulfur
atom. In particular, the sulfone compound exhibits a LUMO energy level
that is markedly lower than those of the corresponding dithienylborane
and dithienylthiophene S,S-dioxide,
suggesting that the combination of boron and sulfone enhances the
electron-accepting properties. In addition, the sulfone unit can be
modified by the Stille cross-coupling reaction, demonstrating its
potential use in other functional p-π* conjugated materials.
Despite the great success of the concept of doping organic compounds with BN units to access new materials with tailored properties, its use in polymer chemistry has only been realized quite recently. Herein, we present a comprehensive study of oligo‐ and poly(arylene iminoborane)s comprising a backbone of phenylene or thiophene moieties, as well as combinations thereof, linked via B=N units. The novel polymers can be regarded as BN analogues of poly(p‐phenylene vinylene) (PPV) or poly(thiophene vinylene) (PTV) or their copolymers, respectively. Our modular synthetic approach allowed us to prepare four polymers and twelve monodisperse oligomers with modulated electronic properties. Alternating electron‐releasing diaminoarylene and electron‐accepting diborylarylene building blocks give rise to a pronounced donor–acceptor character. Effective π‐conjugation over the arylene iminoborane backbone is evidenced by systematic bathochromic shifts of the low‐energy UV‐vis absorption maximum with increasing chain length, which is furthermore supported by crystallographic and computational investigations. Furthermore, all compounds investigated show emission of visible light in the solid state and aggregation‐induced emission (AIE) behavior, due to the presence of partially flexible linear B=N linkages in the backbone.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.