7253-07-8Relevant academic research and scientific papers
Blue fluorescent host compound, and preparation method and device thereof
-
Paragraph 0076-0079, (2020/01/12)
The invention relates to a blue fluorescent host compound, and a preparation method and a device thereof. The structural formula of the blue fluorescent host compound is represented by chemical formula 1 shown in the description. Compared with a conventional material, the blue fluorescent host compound of the invention has the advantages of excellent electroluminescent properties, long device service life and proper color coordinates. The organic light-emitting device prepared from the blue fluorescent host compound adopts the novel compound of the chemical formula 1, so that the device becomes the organic light-emitting device with a high efficiency and a long service life. The preparation method of the blue fluorescent host compound has the advantages of simple process and high yield.
Polymorphism and benzene solvent controlled stimuli responsive reversible fluorescence switching in triphenylphosphoniumfluorenylide crystals
Hariharan,Baby Mariyatra,Mothi,Neels, Antonia,Rosair, Georgina,Anthony, Savarimuthu Philip
, p. 4592 - 4598 (2017/07/11)
Triphenylphosphoniumfluorenylide (TPPFY), a fluorescent fluorene attached molecule, showed polymorphism and benzene solvent induced aggregation enhanced emission (AEE) in the solid state. Crystallization from CH3CN produced non-fluorescent crys
A comprehensive study of substituent effects on poly(dibenzofulvene)s
Wong, Michael Y.,Leung, Louis M.
, p. 512 - 520 (2017/02/05)
We herein report the first cross comparison of 14 poly(dibenzofulvene) derivatives (13 novel examples and the parent poly(dibenzofulvene)) in order to understand how the choice of substituent affects the physical properties of this interesting class of semiconducting polymers. Electron withdrawing substituents decreased the polymerization reactivity and resulted in very low molecular-weight products. Di-substituted poly(dibenzofulvene)s were found to be much less soluble than the mono-analogues which can be explained by the Hansen solubility parameter system. Analysis based on absorption, emission and electrochemistry profiles suggests that polymer solubility is a very important factor that controls the degree of stacking present in the polymer due to synthetic issues. For the first time, the thermal analysis of the parent poly(dibenzofulvene) and its derivatives is reported and it was believed that depolymerization occurred much earlier than the melting transition. We have also demonstrated the orthogonal synthesis of dibenzofulvene monomers using three distinct routes (lithiation, oxidation and Wittig) to cope with functional group compatibility.
Inner workings of a cinchona alkaloid catalyzed oxa-Michael cyclization: Evidence for a concerted hydrogen-bond-network mechanism
Hintermann, Lukas,Ackerstaff, Jens,Boeck, Florian
supporting information, p. 2311 - 2321 (2013/04/10)
Cinchona alkaloids catalyze the oxa-Michael cyclization of 4-(2-hydroxyphenyl)-2-butenoates to benzo-2,3-dihydrofuran-2-yl acetates and related substrates in up to 99 % yield and 91 % ee (ee=enantiomeric excess). Catalyst and substrate variation studies reveal an important role of the alkaloid hydroxy group in the reaction mechanism, but not in the sense of a hydrogen-bonding activation of the carbonyl group of the substrate as assumed by the Hiemstra-Wynberg mechanism of bifunctional catalysis. Deuterium labeling at C-2 of the substrate shows that addition of RO-H to the alkenoate occurs with syn diastereoselectivity of ≥99:1, suggesting a mechanism-based specificity. A concerted hydrogen-bond network mechanism is proposed, in which the alkaloid hydroxy group acts as a general acid in the protonation of the α-carbanionic center of the product enolate. The importance of concerted hydrogen-bond network mechanisms in organocatalytic reactions is discussed. The relative stereochemistry of protonation is proposed as analytical tool for detecting concerted addition mechanisms, as opposed to ionic 1,4-additions. Secret of cyclization: The cinchona alkaloid catalyzed asymmetric oxa-Michael cyclization of 2′-hydroxyphenyl-2-butenoates to benzodihydrofurans proceeds by a highly enantio- and diastereoselective syn-specific addition mode (see scheme). Transition-state activation of the carbonyl group by hydrogen bonding to the catalyst is excluded. This represents a clear-cut demonstration of the importance of concerted hydrogen-bond network mechanisms in cinchona-based asymmetric organocatalysis. Copyright
A facile approach to the synthesis of substituted dibenzofulvenes-precursors to pi-stacked poly(dibenzofulvene)s
Wong, Michael Y.,Leung, Louis M.
experimental part, p. 3973 - 3977 (2010/07/04)
A series of novel substituted (2-methoxy, 2-nitro, 2-bromo, 2-iodo, 2-cyano, and 2-acetyl) and disubstitiuted (2-bromo-7-methoxy, 2-bromo-7-propoxy, 2-bromo-7-hexoxy, 2-nitro-7-propoxy, 2-nitro-7-hexoxy, and 2,7-di-bromo) dibenzofulvenes have been prepared from the corresponding fluorenes with fair to very good overall yields (35.7-66.7%) based on the Wittig chemistry. The new approach enjoyed much simpler experimental procedures and has the advantage of higher functional group tolerance. Preliminary results on their polymerization using solution free-radical approach are also presented.
Synthesis and evaluation of (pyridylmethylene)tetrahydronaphthalenes/- indanes and structurally modified derivatives: Potent and selective inhibitors of aldosterone synthase
Ulmschneider, Sarah,Müller-Vieira, Ursula,Klein, Christian D.,Antes, Iris,Lengauer, Thomas,Hartmann, Rolf W.
, p. 1563 - 1575 (2007/10/03)
Elevated aldosterone levels are key effectors for the development and progression of congestive heart failure and myocardial fibrosis. Recently, we proposed inhibition of aldosterone synthase (CYP11B2) as an innovative strategy for the treatment of these
