3598-30-9Relevant articles and documents
Butterfly Mesogens Based on Carbazole, Fluorene or Fluorenone: Mesomorphous, Gelling, Photophysical, and Photoconductive Properties
Hang, Jun-Fang,Lin, Hang,Zhao, Ke-Qing,Hu, Ping,Wang, Bi-Qin,Monobe, Hirosato,Zhu, Chenhui,Donnio, Bertrand
, p. 1989 - 2002 (2021)
We report a straightforward and generic synthesis of several new series of annulated π-extended poly-(hetero)aromatic hydrocarbons (PAH), with carbazole, fluorene and fluorenone central building blocks by the Suzuki-Miyaura/Scholl tandem reactions. The corresponding series of ditriphenylene discogens with a carbazole or a fluorenone central core, respectively, possess hexagonal columnar mesophases with broad mesophase ranges and high clearing points, as well as demonstrate a strong aggregation tendency in organic solvents as supergelators. The laterally-substituted ditriphenylene mesogens based on dimethyl-fluorene core exhibit a rich polymorphism with rectangular and hexagonal columnar mesophases from low temperatures onward, whereas their dioctyl-fluorene homologues melt directly into the isotropic liquid without showing mesophases. These latter family of compounds are luminescent with very high fluorescent quantum yields, of around 70 % in solution, and show outstanding photocurrent behavior with charge carrier mobility in the 10?2 cm2 V?1 s?1 range, as measured by photocurrent transient time-of-flight (TOF) technique. This straightforward molecular design and simple synthetic strategy proved to be both potent and resilient, and could be generally applied to the fabrication of a great variety of other heteroarene molecular systems as organic semiconductors and electroluminescent materials for potentially low-cost applications.
Electrochemical Control of Bridging Ligand Conformation in a Binuclear Complex-A Possible Basis for a Molecular Switch
Joulie, Laurent F.,Schatz, Erik,Ward, Michael D.,Weber, Frank,Yellowlees, Lesley J.
, p. 799 - 804 (1994)
Reaction of the binucleating bridging ligands 3,3',4,4'-tetrahydroxybiphenyl (H4L1) or 3,3",4,4"-tetrahydroxy-p-terphenyl (H4L2) with 2 equivalents of *2H2O (bipy = 2,2'-bipyridine) results in the formation of binuclear complexes (μ-L)>(2+) 1 (L = L1) and 2 (L = L2) in which the ligand L(4-) has been oxidized to the semiquinone (sq) form L(2-).In each complex the co-ordinated catecholate fragment (cat) may be oxidised reversibly to the semiquinone and quinone (q) redox states, giving the five-membered redox series cat-cat, cat-sq, sq-sq, sq-q and q-q for the bridging ligands.In the sq-sq state the bridging ligands are necessarily planar due to the presence of double bonds between the aromatic rings; in the cat-cat and q-q states there is formally no double-bond character between the aromatic rings and they are free to adopt a twisted conformation.Spectroelectrochemical measurements confirm that in the cat-cat and q-q states, 1 and 2 behave approximately like their mononuclear counterparts and (2+) ; for 1, the results also show that in the mixed-valence sq-q and sq-cat oxidation states the two halves of the ligand are electronically equivalent (i.e. valence delocalised), which is best explained by the bridging ligand retaining the planar confirmation of the sq-sq state.The change from planar to twisted therefore occurs at the extremes of the redox series, on formation of the cat-cat and q-q oxidation states.This control of bridging ligand conformation with oxidation state may form the basis for a molecular switch.
Hydroxylated biphenyls as tyrosinase inhibitor: A spectrophotometric and electrochemical study
Ruzza, Paolo,Serra, Pier Andrea,Fabbri, Davide,Dettori, Maria Antonietta,Rocchitta, Gaia,Delogu, Giovanna
, p. 1034 - 1038 (2016/12/26)
A small collection of C2-symmetry hydroxylated biphenyls was prepared by straightforward methods and the capability to act as inhibitors of tyrosinase has been evaluated by both spectrophotometric and electrochemical assays. Our attention was f
Conversion of Simple Cyclohexanones into Catechols
Liang, Yu-Feng,Li, Xinyao,Wang, Xiaoyang,Zou, Miancheng,Tang, Conghui,Liang, Yujie,Song, Song,Jiao, Ning
supporting information, p. 12271 - 12277 (2016/09/28)
A novel I2-catalyzed direct conversion of cyclohexanones to substituted catechols under mild and simple conditions has been described. This novel transformation is remarkable with the multiple oxygenation and dehydrogenative aromatization processes enabled just by using DMSO as the solvent, oxidant, and oxygen source. This metal-free and simple system demonstrates a versatile protocol for the synthesis of highly valuable substituted catechols and therefore streamlines the synthesis and modification of biologically important molecules for drug discovery.
