28 research outputs found
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 Pentacoordinate Boron-Containing π‑Electron System with Cl–B–Cl Three-Center Four-Electron Bonds
Tricoordinate
boron-containing π-electron systems are an
attractive class of compounds with intense fluorescence and strong
electron-accepting properties. However, the impact of pentacoordination
of the boron atoms on their properties has not been determined. We
now disclose a <i>B</i>,<i>B</i>′-bis(1,8-dichloro-9-anthryl)-substituted
9,10-dihydro-9,10-diboraanthracene as a new pentacoordinate organoboron
compound. In this skeleton, with the aid of the orthogonal arrangement
of the anthryl substituent, the B and Cl atoms can form a three-center
four-electron (3c–4e) Cl–B–Cl bond. The pentacoordination
of the boron atom significantly perturbs the electronic structure
and thereby the photophysical and electrochemical properties
Polycyclic π-Electron System with Boron at Its Center
We disclose a new planarized triarylborane in which the
tri-coordinated
boron atom is embedded in a fully fused polycyclic π-conjugated
skeleton. The compound shows high stability toward oxygen, water,
and silica gel, despite the absence of steric protection around the
B atom. Reflecting the electron-donating character of the π-skeleton
and the electron-accepting character of the B atom, this compound
shows broad absorption bands that cover the entire visible region
and a fluorescence in the visible/near-IR region. In addition, this
compound shows dramatic property changes upon formation of a tetra-coordinated
borate, such as thermochromic behavior in the presence of pyridine
Polycyclic π-Electron System with Boron at Its Center
We disclose a new planarized triarylborane in which the
tri-coordinated
boron atom is embedded in a fully fused polycyclic π-conjugated
skeleton. The compound shows high stability toward oxygen, water,
and silica gel, despite the absence of steric protection around the
B atom. Reflecting the electron-donating character of the π-skeleton
and the electron-accepting character of the B atom, this compound
shows broad absorption bands that cover the entire visible region
and a fluorescence in the visible/near-IR region. In addition, this
compound shows dramatic property changes upon formation of a tetra-coordinated
borate, such as thermochromic behavior in the presence of pyridine
Photodissociation of B–N Lewis Adducts: A Partially Fused Trinaphthylborane with Dual Fluorescence
The synthesis of a planarized trinaphthylborane
with partially
fused structure is presented. This compound shows not only high chemical
and thermal stability but also sufficient Lewis acidity to form Lewis
adducts with pyridine derivatives in solution. The B–N Lewis
adducts exhibit unprecedented photodissociation behavior in the excited
state, reminiscent of the photogeneration of carbenium ions from triarylmethane
leuco dyes. Consequently, these B–N Lewis adducts exhibit dual
fluorescence emission arising from the initial tetracoordinate B–N
adducts and the photodissociated tricoordinate boranes
Polycyclic π-Electron System with Boron at Its Center
We disclose a new planarized triarylborane in which the
tri-coordinated
boron atom is embedded in a fully fused polycyclic π-conjugated
skeleton. The compound shows high stability toward oxygen, water,
and silica gel, despite the absence of steric protection around the
B atom. Reflecting the electron-donating character of the π-skeleton
and the electron-accepting character of the B atom, this compound
shows broad absorption bands that cover the entire visible region
and a fluorescence in the visible/near-IR region. In addition, this
compound shows dramatic property changes upon formation of a tetra-coordinated
borate, such as thermochromic behavior in the presence of pyridine
Polycyclic π-Electron System with Boron at Its Center
We disclose a new planarized triarylborane in which the
tri-coordinated
boron atom is embedded in a fully fused polycyclic π-conjugated
skeleton. The compound shows high stability toward oxygen, water,
and silica gel, despite the absence of steric protection around the
B atom. Reflecting the electron-donating character of the π-skeleton
and the electron-accepting character of the B atom, this compound
shows broad absorption bands that cover the entire visible region
and a fluorescence in the visible/near-IR region. In addition, this
compound shows dramatic property changes upon formation of a tetra-coordinated
borate, such as thermochromic behavior in the presence of pyridine
Heterotriangulenes π‑Expanded at Bridging Positions
A series of nitrogen-containing heterotriangulenes
expanded at
the bridging positions has been synthesized. Among them, a dibenzo[<i>c,g</i>]fluorenylidene-substituted derivative has a highly twisted
conformation for the overcrowded alkene moieties, which impart a highly
electron-accepting character to the electron-donating heterotriangulene
skeleton and thereby an NIR absorption as well as multiredox properties
with a low reduction potential
Heterotriangulenes π‑Expanded at Bridging Positions
A series of nitrogen-containing heterotriangulenes
expanded at
the bridging positions has been synthesized. Among them, a dibenzo[<i>c,g</i>]fluorenylidene-substituted derivative has a highly twisted
conformation for the overcrowded alkene moieties, which impart a highly
electron-accepting character to the electron-donating heterotriangulene
skeleton and thereby an NIR absorption as well as multiredox properties
with a low reduction potential
Heterotriangulenes π‑Expanded at Bridging Positions
A series of nitrogen-containing heterotriangulenes
expanded at
the bridging positions has been synthesized. Among them, a dibenzo[<i>c,g</i>]fluorenylidene-substituted derivative has a highly twisted
conformation for the overcrowded alkene moieties, which impart a highly
electron-accepting character to the electron-donating heterotriangulene
skeleton and thereby an NIR absorption as well as multiredox properties
with a low reduction potential