- Targeted and selective HOMO energy control by fine regulation of molecular planarity and its effect on the interfacial charge transfer process in dye-sensitized solar cells
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In terms of the in-depth development of organic dyes, targeted and selective energy control is becoming a more and more important objective. Herein, four indoline sensitizers based on D-π-A-π-A construction were designed and synthesized with exactly the same donor and acceptor segments. Their molecular planarity was regulated by introducing various side chains into donor bridges. Interestingly, along with an improvement of planarity at a donor bridge, the HOMO levels of the dyes lift gradually, and more importantly, their LUMO levels remain at around the same value. Besides, better molecular planarity is obviously preferred to obtain higher charge injection efficiency but, an overly planar molecule may cause an overly high HOMO level, leading to poor dye regeneration efficiency. Furthermore, an appropriate side chain also restrains charge recombination to some extent, while an overly large side chain gives more chance for I3- to recombine with charge in the conduction band. Accordingly, our results demonstrated that regulation of planarity at a donor bridge not only provides targeted and selective control of the HOMO of the dye, but also enable fine adjustment with multiple interfacial charge transfer processes. Molecular planarity deserves to play an important role in the design of organic dyes, providing a significant strategy for the further development of organic sensitizers.
- Zhang, Fengyu,Wang, Ran,Wang, Yajun,Zhang, Xiaomin,Liu, Bo
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p. 6256 - 6264
(2019/04/04)
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- The Discovery of Citral-Like Thiophenes in Fried Chicken
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The isomers of 3,7-dimethyl-2,6-octadienal, more commonly known together as citral, are two of the most notable natural compounds in the flavor and fragrance industry. However, both isomers are inherently unstable, limiting their potential use in various applications. To identify molecules in nature that can impart the fresh lemon character of citral while demonstrating stability under acidic and thermal conditions has been a major challenge and goal for the flavor and fragrance industry. In the study of fried chicken, several alkyl thiophenecarbaldehydes were identified by gas chromatography-mass spectrometry and gas chromatography-olfactometry that provided a similar citral-like aroma. The potential mechanism of formation in fried chicken is discussed. Furthermore, in order to explore the organoleptic properties of this structural backbone, a total of 35 thiophenecarbaldehyde derivatives were synthesized or purchased for evaluation by odor and taste. Certain organoleptic trends were observed as the length of the alkyl or alkenyl chain increased or when the chain was moved to different positions on the thiophene backbone. The 3-substituted alkyl thiophenecarbaldehydes, specifically 3-butyl-2-thiophenecarbaldehyde and 3-(3-methylbut-2-en-1-yl)-2-thiophenecarbaldehyde, exhibited strong citrus and citral-like notes. Several alkyl thiophenecarbaldehydes were tested in high acid stability trials (4 °C vs 38 °C) and outperformed citral both in terms of maintaining freshness over time and minimizing off-notes. Additional measurements were completed to calculate the odor thresholds for a select group of thiophenecarbaldehydes, which were found to be between 4.7-215.0 ng/L in air.
- Cannon, Robert J.,Curto, Nicole L.,Esposito, Cynthia M.,Payne, Richard K.,Janczuk, Adam J.,Agyemang, David O.,Cai, Tingwei,Tang, Xiao-Qing,Chen, Michael Z.
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p. 5690 - 5699
(2017/07/24)
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- Novel S1P1 receptor agonists - Part 4: Alkylaminomethyl substituted aryl head groups
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In a previous communication we reported on the discovery of alkylamino pyridine derivatives (e.g. 1) as a new class of potent, selective and efficacious S1P1 receptor (S1PR1) agonists. However, more detailed profiling revealed that this compound class is phototoxic in vitro. Here we describe a new class of potent S1PR1 agonists wherein the exocyclic nitrogen was moved away from the pyridine ring (e.g. 11c). Further structural modifications led to the identification of novel alkylaminomethyl substituted phenyl and thienyl derivatives as potent S1PR1 agonists. These new alkylaminomethyl aryl compounds showed no phototoxic potential. Based on their in vivo efficacy and ability to penetrate the brain, the 5-alkyl-aminomethyl thiophenes appeared to be the most interesting class. Potent and selective S1PR1 agonist 20e, for instance, maximally reduced the blood lymphocyte count (LC) for 24 h after oral administration of 10 mg/kg to rat and its brain concentrations reached >500 ng/g over 24 h.
- Lescop, Cyrille,Müller, Claus,Mathys, Boris,Birker, Magdalena,De Kanter, Ruben,Kohl, Christopher,Hess, Patrick,Nayler, Oliver,Rey, Markus,Sieber, Patrick,Steiner, Beat,Weller, Thomas,Bolli, Martin H.
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supporting information
p. 222 - 238
(2016/04/20)
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- Aminopyrazine inhibitors binding to an unusual inactive conformation of the mitotic kinase Nek2: SAR and structural characterization
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We report herein the first systematic exploration of inhibitors of the mitotic kinase Nek2. Starting from HTS hit aminopyrazine 2, compounds with improved activity were identified using structure-based design. Our structural biology investigations reveal two notable observations. First, 2 and related compounds bind to an unusual, inactive conformation of the kinase which to the best of our knowledge has not been reported for other types of kinase inhibitors. Second, a phenylalanine residue at the center of the ATP pocket strongly affects the ability of the inhibitor to bind to the protein. The implications of these observations are discussed, and the work described here defines key features for potent and selective Nek2 inhibition, which will aid the identification of more advanced inhibitors of Nek2.
- Whelligan, Daniel K.,Solanki, Savade,Taylor, Dawn,Thomson, Douglas W.,Cheung, Kwai-Ming J.,Boxall, Kathy,Mas-Droux, Corine,Barillari, Caterina,Burns, Samantha,Grummitt, Charles G.,Collins, Ian,Van Montfort, Rob L. M.,Aherne, G. Wynne,Bayliss, Richard,Hoelder, Swen
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supporting information; experimental part
p. 7682 - 7698
(2010/12/25)
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- THIOPHENE DERIVATIVES AS AGONISTS OF S1P1/EDG1
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The invention relates to novel thiophene derivatives (1), their preparation and their use as pharmaceutically active compounds.Said compounds particularly act as immunomodulating agents. Formula (I).
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Page/Page column 11; 12
(2010/11/03)
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- STUDIES OF SOME HINDERED 2,2'-BITHIENYLS AND 3,3'-BRIDGED 2,2'-BITHIENYLS WITH SPECIAL REFERENCE TO THEIR UV SPECTRA AND OXUDATION POTENTIALS
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Some hindered bithienyl derivatives have been synthesized by cross-coupling reaction of Grignard reagents using NiCl2(Dppp) (dppp= Ph2CH2CH2PPh2) or by reductive dimerization in the presence of Zn/NiCl2(PPh3)2.Their UV spectra and oxidation potentials are discussed in terms of their coplaranity and of the inductive effect of the substituent.Keywords: 2,2'-bithienyls; 3,3'-bridged bithienyls; UV Spectra; Oxidation Potenyials; Sonochemical Grignard Reactions
- Amer, A.,Burkhardt, A.,Nkansah, A.,Shabana, R.,Galal, A.,,et al.
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