La fundación de la Madrasa al-Adāb por la Asociación de ulemas musulmanes argelinos en la ciudad de Hennaya (Tremecén) en 1950

A biphenyl-fused BODIPY was synthesized through a facile oxidative cyclization of peripheral aryl-substituents at the β-position of the BODIPY unit. The extended π-system of the fused BODIPY induces near-infrared (NIR) absorption and strong π–π interactions in the solid state. These features are beneficial for the application of the dye as a functional material. The biphenyl-fused BODIPY dye was demonstrated to exhibit photocurrent conversion ability on the basis of its <i>n</i>-type semiconducting property

A Study of 1,2-Dihydro-1,2-azaborine in a π-Conjugated System

The reaction of N-Boc-protected bis(5-phenyl-2-pyrrolyl)borane with BF3·OEt2 produced 3-(phenylpyrrolyl)-6-phenyl-1,2-dihydro-1,2-azaborine in moderate yield. This compound showed an absorption band at a longer wavelength compared to that of its benzene analogue and also exhibited an intense red-shifted fluorescence with a high quantum yield close to unity. According to the X-ray structural analysis, cyclic voltammetry, and theoretical calculations, the 1,2-dihydro-1,2-azaborine acts not like a benzene analogue but like a cyclohexadiene analogue in the extended π-conjugated skeleton

Thiophene-Fused Ladder Boroles with High Antiaromaticity

A series of polycyclic thiophene-fused boroles were synthesized on the basis of stepwise substitution reactions from thienylboronic ester precursors. In these ladder-type π-conjugated systems, the thiophene-fused structure enhances the antiaromaticity of the borole ring. This trend is opposite to the conventional understanding that the arene-fused structure decreases the antiaromaticity of the 4π-electron ring skeletons. The ladder boroles exhibited characteristic properties such as long-wavelength absorptions and low reduction potentials

A Study of 1,2-Dihydro-1,2-azaborine in a π-Conjugated System

The reaction of N-Boc-protected bis(5-phenyl-2-pyrrolyl)borane with BF3·OEt2 produced 3-(phenylpyrrolyl)-6-phenyl-1,2-dihydro-1,2-azaborine in moderate yield. This compound showed an absorption band at a longer wavelength compared to that of its benzene analogue and also exhibited an intense red-shifted fluorescence with a high quantum yield close to unity. According to the X-ray structural analysis, cyclic voltammetry, and theoretical calculations, the 1,2-dihydro-1,2-azaborine acts not like a benzene analogue but like a cyclohexadiene analogue in the extended π-conjugated skeleton

A Radical Anion of Structurally Constrained Triphenylborane

Chemical reduction of the structurally constrained triphenylborane 1 with K produced a radical anion. EPR analysis demonstrated the delocalization of the unpaired electron spin density over the entire π skeleton to a greater extent than is the case for a nonconstrained Ph3B radical anion. DFT calculations indicated that the coplanarization of the benzene rings with the boron plane and the shortening of the B–C bond lengths by the structural constraint are responsible for the spin delocalization. The geometry optimization also suggested a bowl-shaped conformation as a viable local minimum structure in addition to the planar conformation. X-ray crystal structure analysis indeed revealed the nonplanar structure of the radical anion 1•–

Thiophene-Fused Ladder Boroles with High Antiaromaticity

A series of polycyclic thiophene-fused boroles were synthesized on the basis of stepwise substitution reactions from thienylboronic ester precursors. In these ladder-type π-conjugated systems, the thiophene-fused structure enhances the antiaromaticity of the borole ring. This trend is opposite to the conventional understanding that the arene-fused structure decreases the antiaromaticity of the 4π-electron ring skeletons. The ladder boroles exhibited characteristic properties such as long-wavelength absorptions and low reduction potentials

Thiophene-Fused Ladder Boroles with High Antiaromaticity

A series of polycyclic thiophene-fused boroles were synthesized on the basis of stepwise substitution reactions from thienylboronic ester precursors. In these ladder-type π-conjugated systems, the thiophene-fused structure enhances the antiaromaticity of the borole ring. This trend is opposite to the conventional understanding that the arene-fused structure decreases the antiaromaticity of the 4π-electron ring skeletons. The ladder boroles exhibited characteristic properties such as long-wavelength absorptions and low reduction potentials

Thiophene-Fused Ladder Boroles with High Antiaromaticity

A series of polycyclic thiophene-fused boroles were synthesized on the basis of stepwise substitution reactions from thienylboronic ester precursors. In these ladder-type π-conjugated systems, the thiophene-fused structure enhances the antiaromaticity of the borole ring. This trend is opposite to the conventional understanding that the arene-fused structure decreases the antiaromaticity of the 4π-electron ring skeletons. The ladder boroles exhibited characteristic properties such as long-wavelength absorptions and low reduction potentials

Thiophene-Fused Ladder Boroles with High Antiaromaticity

A series of polycyclic thiophene-fused boroles were synthesized on the basis of stepwise substitution reactions from thienylboronic ester precursors. In these ladder-type π-conjugated systems, the thiophene-fused structure enhances the antiaromaticity of the borole ring. This trend is opposite to the conventional understanding that the arene-fused structure decreases the antiaromaticity of the 4π-electron ring skeletons. The ladder boroles exhibited characteristic properties such as long-wavelength absorptions and low reduction potentials

A Radical Anion of Structurally Constrained Triphenylborane

Chemical reduction of the structurally constrained triphenylborane <b>1</b> with K produced a radical anion. EPR analysis demonstrated the delocalization of the unpaired electron spin density over the entire π skeleton to a greater extent than is the case for a nonconstrained Ph₃B radical anion. DFT calculations indicated that the coplanarization of the benzene rings with the boron plane and the shortening of the B–C bond lengths by the structural constraint are responsible for the spin delocalization. The geometry optimization also suggested a bowl-shaped conformation as a viable local minimum structure in addition to the planar conformation. X-ray crystal structure analysis indeed revealed the nonplanar structure of the radical anion <b>1</b>^{<b>•–</b>}