Search results for "Ovalene"
showing 8 items of 8 documents
Regioselective Bromination and Functionalization of Dibenzo[hi,st]ovalene as Highly Luminescent Nanographene with Zigzag Edges.
2019
Dibenzo[hi,st]ovalene (DBOV) is a nanographene with a combination of zigzag and armchair edges, consisting of 38 sp2 carbons. Excellent optical properties with strong red emission have been demonstrated. Here we report the regioselective bromination of DBOV bearing two mesityl groups (DBOV-Mes) by treatment with N-bromosuccinimide (NBS) under mild conditions. The dibrominated DBOV was further subjected to transition-metal-catalyzed cross-coupling reactions, that is, Suzuki and Sonogashira coupling, demonstrating the edge-decoration of DBOV with different functional groups. Notably, DBOVs arylated at the bay regions showed intense red emission and enhanced fluorescence quantum yields of up t…
A Highly Luminescent Nitrogen-Doped Nanographene as an Acid- and Metal-Sensitive Fluorophore for Optical Imaging.
2021
Dibenzo[hi,st]ovalene (DBOV) has excellent photophysical properties, including strong fluorescence and high ambient stability. Moreover, the optical blinking properties of DBOV have enabled optical super-resolution single-molecule localization microscopy with an imaging resolution beyond the diffraction limit. Various organic and inorganic fluorescent probes have been developed for super-resolution imaging, but those sensitive to pH and/or metal ions have remained elusive. Here, we report a diaza-derivative of DBOV (N-DBOV), synthesized in eight steps with a total yield of 15%. Nitrogen (N)-bearing zigzag edges were formed through oxidative cyclization of amino groups in the last step. UV-v…
Dibenzo[hi,st]ovalene as Highly Luminescent Nanographene: Efficient Synthesis via Photochemical Cyclodehydroiodination, Optoelectronic Properties, an…
2019
Dibenzo[hi,st]ovalene (DBOV), as a new nanographene, has demonstrated promising optical properties, such as red emission with a high fluorescence quantum yield of 79% and stimulated emission, as well as high thermal stability and photostability, which indicated its promise as a light-emitting and optical gain material. However, the previous synthetic routes required at least 12 steps. This obstructed access to different derivatives, e.g., to obtain crystals suitable for X-ray diffraction analysis and to tune the optoelectronic properties. Here, we report an efficient synthetic pathway to DBOV based on a sequential iodination-benzannulation of bi(naphthylphenyl)diyne, followed by photochemic…
CCDC 1852851: Experimental Crystal Structure Determination
2019
Related Article: Qiang Chen, Stefan Thoms, Sven Stöttinger, Dieter Schollmeyer, Klaus Müllen, Akimitsu Narita, Thomas Basché|2019|J.Am.Chem.Soc.|141|16439|doi:10.1021/jacs.9b08320
CCDC 1893173: Experimental Crystal Structure Determination
2020
Related Article: Qiang Chen, Di Wang, Martin Baumgarten, Dieter Schollmeyer, Klaus Müllen, Akimitsu Narita|2019|Chem.Asian J.|14|1703|doi:10.1002/asia.201801822
CCDC 1946099: Experimental Crystal Structure Determination
2020
Related Article: Qiang Chen, Dieter Schollmeyer, Klaus Müllen, Akimitsu Narita|2019|J.Am.Chem.Soc.|141|19994|doi:10.1021/jacs.9b10957
Synthesis and helical supramolecular organization of discotic liquid crystalline dibenzo[hi,st]ovalene
2019
Dibenzo[hi,st]ovalene (DBOV) has emerged as a new polycyclic aromatic hydrocarbon (PAH) with intriguing optical properties with strong red emission. Nevertheless, DBOV derivatives thus far synthesized either had mesityl groups that hinder the pi-pi stacking of the aromatic cores or showed low solubility, and the self-assembly of DBOVs has not been investigated. In this work, two 3,4,5-tris(dodecyloxy)phenyl (TDOP) groups are introduced at the meso-positions of DBOV in order to enhance its solubility without compromising the intermolecular interactions. The obtained DBOV-TDOP forms at elevated temperatures a discotic liquid crystalline phase. Due to pi-pi-stacking interactions as well as loc…
Synthesis of Circumpyrene by Alkyne Benzannulation of Brominated Dibenzo[hi,st]ovalene
2019
A transition-metal catalyzed alkyne benzannulation allowed an unprecedented synthesis of circumpyrene, starting from 3,11-dibromo-6,14-dimesityldibenzo[hi,st]ovalene (DBOV). The circumpyrene was characterized by a combination of NMR, mass spectrometry, and single-crystal X-ray diffraction analysis, revealing its multizigzag-edged structure. Two newly introduced C═C bonds in circumpyrene strongly perturbed the electronic structures of DBOV, as evidenced by increased optical and electrochemical energy gaps. This is in good agreement with an increased number of Clar's sextets as well as a decreased number of π-electrons in the conjugation pathway of circumpyrene, according to anisotropy of the…