- The Influence of Solubilizing Chain Stereochemistry on Small Molecule Photovoltaics
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Three stereochemically pure isomers and two isomeric mixtures of a solution-processable diketopyrrolopyrrole-containing oligothiophene (SMDPPEH) have been used to study the effect of 2-ethylhexyl solubilizing group stereochemistry on the film morphology and bulk heterojunction (BHJ) solar cell characteristics of small molecule organic photovoltaics. The different SMDPPEH stereoisomer compositions exhibit nearly identical optoelectronic properties in the molecularly dissolved state, as well as in amorphous films blended with PCBM. However, for films in which SMDPPEH crystallization is induced by thermal annealing, significant differences in molecular packing between the different stereoisomer formulations are observed. These differences are borne out in photovoltaic device characteristics for which unannealed devices show very similar behavior, while after annealing the RR- and SS-SMDPPEH enantiomers show blue-shifted peak EQE relative to the SMDPPEH isomer mixtures. Unannealed devices made from the most crystalline stereoisomer, meso RS-SMDPPEH, are not completely amorphous, and show improved photocurrent generation as a result. Unlike the other compounds, after thermal annealing the RS-SMDPPEH devices show reduced device performance. The results reveal that the chirality of commonly used 2-ethylhexyl solubilizing chains can have a significant effect on the morphology, absorption, and optimum processing conditions of small molecule organic thin films used as photovoltaic device active layers.
- Zerdan, Raghida Bou,Shewmon, Nathan T.,Zhu, Yu,Mudrick, John P.,Chesney, Kyle J.,Xue, Jiangeng,Castellano, Ronald K.
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- Synthesis of Phosphonic Acid Ligands for Nanocrystal Surface Functionalization and Solution Processed Memristors
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Here, we synthesized 2-ethylhexyl, 2-hexyldecyl, 2-[2-(2-methoxyethoxy)ethoxy]ethyl, oleyl, and n-octadecyl phosphonic acid and used them to functionalize CdSe and HfO2 nanocrystals. In contrast to branched carboxylic acids, postsynthetic surface functionalization of CdSe and HfO2 nanocrystals was readily achieved with branched phosphonic acids. Phosphonic acid capped HfO2 nanocrystals were subsequently evaluated as memristors using conductive atomic force microscopy. We found that 2-ethylhexyl phosphonic acid is a superior ligand, combining a high colloidal stability with a compact ligand shell that results in a record-low operating voltage that is promising for application in flexible electronics.
- De Roo, Jonathan,Zhou, Zimu,Wang, Jiaying,Deblock, Loren,Crosby, Alfred J.,Owen, Jonathan S.,Nonnenmann, Stephen S.
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p. 8034 - 8039
(2018/10/25)
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- A method for preparing different Xin thiol (by machine translation)
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The present invention relates to the field of fine chemicals, in particular relates to a process for preparing thiols different Xin, it adopts isooctanol, hexabromo, DMAP catalyst, thiourea, polyesters sodium solution, such as sulfuric acid the original supplementary material to brominated, condensation, hydrolysis reaction, after the reaction, then drying and rectification to get different Xin thiol finished product. The preparation method is simple, few steps, yield as high as 94.16%, and in the bromination reaction not introduced in phosphorus and bromine from participating in the reaction reduces the security risk coefficient. (by machine translation)
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Paragraph 0047; 0048; 0049; 0050; 0051
(2017/08/28)
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- Tribromoisocyanuric acid/triphenylphosphine: A new system for conversion of alcohols into alkyl bromides
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An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/ tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzylic and allylic alcohols, and their corresponding bromides are obtained in 67-82 percent yield. Tertiary alcohols do not react under these conditions.
- De Andrade, Vitor S.C.,De Mattos, Marcio C.S.
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p. 975 - 979
(2014/06/24)
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- Efficient procedures to prepare primary and secondary alkyl halides from alkanols via the corresponding sulfonates under mild conditions
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The study presented herein shows that sulfonate/halide exchange can be advantageously performed in THF to avoid several side reactions such as elimination and epimerization when the reaction is performed from a chiral alkyl sulfonate or a substrate having a C-H acidic chiral center. The main limitation of this procedure was found to be the conversion of secondary alkyl sulfonates to alkyl chlorides. In this case, the addition of a catalytic amount of manganese chloride clearly accelerates the rate and the efficiency of the reaction. Copyright
- Cahiez, Gerard,Gager, Olivier,Moyeux, Alban,Delacroix, Thomas
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supporting information; experimental part
p. 1519 - 1528
(2012/07/03)
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- Scavenger assisted combinatorial process for preparing libraries of tertiary amine compounds
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This invention relates to a novel solution phase process for the preparation of tertiary amine combinatorial libraries. These libraries have utility for drug discovery and are used to form wellplate components of novel assay kits.
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- Pheromones, 89.- Wittig Syntheses of Alkyl-Branched and Cyclic Analogs of (Z)-5-Decenyl Acetate, the Sex Pheromone of Agrotis segetum (Lepitoptera: Noctuidae)
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By means of (Z)-selective Wittig olefination alkyl-branched and cyclic analogs of (Z)-5-decenyl acetate, the sex pheromone of the turnip moth, Agrotis segetum (Lepidoptera: Noctuidae), have been synthesized. Key Words: Pheromones / (Z)-5-decenyl acetate / Wittig reactions / Agrotis segetum
- Albores, Martha,Bestmann, Hans Juergen,Doehla, Bodo,Hirsch, Hans-Ludwig,Roesel, Peter,Vostrowsky, Otto
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p. 231 - 236
(2007/10/02)
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- SELECTIVE HYDROBROMINATION OF BRANCHED ALCOHOLS USING PHASE TRANSFER CATALYSIS
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In the presence of quaternary ammonium phase transfer catalysts hydrobromination of branched alcohols proceed via selective SN2 mechanism practically without rearrangements.
- Dakka, Gihad,Sasson, Yoel
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p. 1223 - 1224
(2007/10/02)
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