Swallow-Tail Substituted Liquid Crystalline Perylene Bisimides: Synthesis and Thermotropic Properties.
Tailor-made synthesis and structure-property relationship of several swallow-tail N-substituted perylene bisimide (PBI) dyes are presented. PBI derivatives were synthesized by two distinct synthetic approaches, the details being evaluated herein. All the PBIs carry either alkyl swallow-tail or oligo...
| Publicado en: | Journal of the American Chemical Society Vol. 131; no. 40; pp. 14442 - 14454 |
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| Autores principales: | , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
10/14/2009
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=44750086&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 44750086 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 10/14/2009 vid: 131 iid: 40 pid: 997 pub: American Chemical Society artinfo: ui: 44750086 10.1021/ja905260c ppf: 14442 ppct: 12 formats: tig: atl: Swallow-Tail Substituted Liquid Crystalline Perylene Bisimides: Synthesis and Thermotropic Properties. aug: au: Wicklein, André Lang, Andreas Muth, Mathis Thelakkat, Mukundan affil: Department of Macromolecular Chemistry I, Applied Functional Polymers, Universität Bayreuth, Universitatsstraße 30, 95440 Bayreuth, Germany su: Perylene Thermotropism Microscopy Optical diffraction Crystallization sug: subj: Perylene Thermotropism Microscopy Optical diffraction Crystallization ab: Tailor-made synthesis and structure-property relationship of several swallow-tail N-substituted perylene bisimide (PBI) dyes are presented. PBI derivatives were synthesized by two distinct synthetic approaches, the details being evaluated herein. All the PBIs carry either alkyl swallow-tail or oligoethyl-englycolether (OEG) swallow-tail moieties as N-substituents, and many of them are unsymmetrically substituted. We avoided substitution at bay positions of the perylene core to maintain the planarity and strong r-v interactions, which favor intermolecular order and charge carrier transport. The thermotropic behavior, which is strongly influenced by the nature of the substituents was investigated using differential scanning calorimetry (DSC), polarization optical microscopy (POM), and X-ray diffraction measurements (XRD). The introduction of OEG swallow-tail units facilitates thermotropic liquid crystalline behavior in most cases and the unsymmetrical substitution allowed the tuning of the mesophase-width. The mesophases exhibit characteristic columnar hexagonal (Col) packing arising from π-π interactions between cofacially orientated perylene molecules. Thus, the inherent tendency of PBI molecules for crystallization could be effectively suppressed by incorporating flexible OEG swallow-tail units only at imide positions. This molecular design was crucial to obtain liquid crystallinity and intracolumnar long-range order. The substituents did not influence the electronic energy levels such as HOMO and LUMO. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2009 holdings: @attributes: islocal: N |
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