- Substituent Effects That Control Conjugated Oligomer Conformation through Non-covalent Interactions
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Although understanding the conformations and arrangements of conjugated materials as solids is key to their prospective applications, predictive power over these structural factors remains elusive. In this work, substituent effects tune non-covalent interactions between side-chain fluorinated benzyl esters and main-chain terminal arenes, in turn controlling the conformations and interchromophore aggregation of three-ring phenylene-ethynylenes (PEs). Cofacial fluoroarene-arene (ArF-ArH) interactions cause twisting in the PE backbone, interrupting intramolecular conjugation as well as blocking chromophore aggregation, both of which prevent the typically observed bathochromic shift observed upon transitioning PEs from solution to solid. This work highlights two structural factors that determine whether the ArF-ArH interactions, and the resulting twisted, unaggregated chromophores, occur in these solids: (i) the electron-releasing characteristic of substituents on ArH, with more electron-releasing character favoring ArF-ArH interactions, and (ii) the fluorination pattern of the ArF ring, with 2,3,4,5,6-pentafluorophenyl favoring ArF-ArH interactions over 2,4,6-trifluorophenyl. These trends indicate that considerations of electrostatic complementarity, whether through a polar-π or substituent-substituent mechanism, can serve as an effective design principle in controlling the interaction strengths, and therefore the optoelectronic properties, of these molecules as solids.
- Sharber, Seth A.,Baral, Rom Nath,Frausto, Fanny,Haas, Terry E.,Müller, Peter,Thomas, Samuel W.
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p. 5164 - 5174
(2017/05/04)
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- Staudinger ligation towards cyclodextrin dimers in aqueous/organic media. Synthesis, conformations and guest-encapsulation ability
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β-Cyclodextrin (β-CD) dimers have been prepared using the bioorthogonal Staudinger ligation for the first time. In addition to a known linker, methyl 2-(diphenylphosphanyl)terephthalate, a doubly active linker was specifically developed that enabled conne
- Manouilidou, Malamatenia D.,Lazarou, Yannis G.,Mavridis, Irene M.,Yannakopoulou, Konstantina
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p. 774 - 783
(2014/05/06)
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- Preparation of phosphonoterephthalic acids via palladium-catalyzed coupling of aromatic iodoesters
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The current article reports in detail the preparation of two phosphonoterephthalic acids: 2-phosphonoterephthalic acid (1) and 2,5-diphosphonoterephthalic acid (2). Efficient, scalable syntheses have been developed for both compounds based on Pd-catalyzed
- Ivan, Nathaniel,Benin, Vladimir,Morgan, Alexander B.
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supporting information
p. 1831 - 1836
(2013/05/22)
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- Synthesis and characterization of a low-bandgap poly(arylene ethynylene) having donor-acceptor type chromophores in the side chain
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A low-bandgap poly(arylene ethynylene) (PAE) having donor-acceptor type chromophores in the side chain was synthesized. A π-conjugated PAE precursor having electron-rich dioctylanilino-substituted alkynes in the side chain was polymerized through Sonogashira cross-coupling reaction between functional monomers M-I with terminal acetylenes and M-II with diiodide, using tetrakis(tripheneylphosphine)palladium and copper iodide catalysts in a mixed solvent of triethylamine and tetrahydrofuran (THF) at 50°C. The electronically rich N,N-dioctylamino groups in M-I activated the alkynes in the side chains of M-I, thus making the selective reaction of sidechain alkynes with TCNE possible in the post-functionalization step. The selective reaction of TCNE (tetracyanoethylene) with activated dioctylanilino substituted alkynes in the side chains of precursor polymer afforded the target poly(arylene ethynylene). This unique polymer shows enhanced thermal stability and exhibits strong intramolecular charge-transfer interactions, resulting in a very low bandgap of poly(arylene ethynylene).
- Huang, Wenyi,Chen, Hongyan
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p. 2032 - 2037
(2013/04/24)
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- Structure, theoretical studies, and coupling reactions of some new cyclic boronic esters
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The present report describes the X-ray structural and theoretical studies of some new pinacolboronate esters, and it also outlines the use of the target structures in Suzuki coupling reactions to produce new aromatic or heteroaromatic esters and amides. X
- Kuttler, Andrew,Durganala, Sravanthi,Fratini, Albert,Morgan, Alexander B.,Benin, Vladimir
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p. 361 - 371
(2013/09/23)
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- Synthesis and photoswitching studies of OPE-embedded difurylperfluorocyclopentenes
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We report the synthesis and photochemical behavior of five photochromic molecular switches 7a-e with attached molecular wires based on differently substituted oligo(phenylene ethynylene) (OPE) building blocks. The switchable molecular wires 7a-e were buil
- Wolf, Jannic,Eberspaecher, Iris,Groth, Ulrich,Huhn, Thomas
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p. 8366 - 8375
(2013/09/24)
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- Synthesis and flame retardant testing of new boronated and phosphonated aromatic compounds
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The present report describes the preparation and use of some dimethyl terephthalate derivatives in transition metal-catalyzed coupling reactions to produce new reactive flame retardants. Dimethyl iodoterephthalate and dimethyl 2,5-diiodoterephthalate were
- Benin, Vladimir,Durganala, Sravanthi,Morgan, Alexander B.
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scheme or table
p. 1180 - 1190
(2012/03/27)
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- Design principle of conjugated polyelectrolytes to make them water-soluble and highly emissive
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The correlation between the molecular design of a conjugated polyelectrolyte (CPE) and its aggregated structure and the emissive properties in water is systematically investigated by means of UV-vis spectrometry, fluorescence spectroscopy, and scanning/tr
- Lee, Kangwon,Kim, Hyong-Jun,Kim, Jinsang
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p. 1076 - 1086
(2012/07/30)
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- Fluorescent chemosensors based on energy migration in conjugated polymers: The molecular wire approach to increased sensitivity
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We demonstrate herein how conjugated polymers (molecular wires) can be used to interconnect (wire in series) receptors to produce fluorescent chemosensory systems with sensitivity enhancements over single receptor analogues. The enhancement mechanism in t
- Zhou, Qin,Swager, Timothy M.
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p. 12593 - 12602
(2007/10/03)
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