- 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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supporting information
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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- 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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scheme or table
p. 1076 - 1086
(2012/07/30)
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- PdII-catalyzed monoselective ortho halogenation of C-H bonds assisted by counter cations: A complementary method to directed ortho lithiation
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(Chemical Equation Presented) When the counterion counts: The yield and selectivity of the title transformation of benzoic acid derivatives were improved greatly by using tetraalkyl ammonium salts as additives (see scheme; monoselectivity: 5:1-18:1). These effects are attributed to the influence of counter cations. The halogenated products are versatile intermediates for the construction of substituted aromatic compounds. DMF=N,N-dimethylformamide.
- Mei, Tian-Sheng,Giri, Ramesh,Maugel, Nathan,Yu, Jin-Quan
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supporting information; experimental part
p. 5215 - 5219
(2009/04/11)
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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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