Langmuir-Blodgett films of amphiphilic bis(tetrathiafulvalene) macrocycles with four alkyl chains
Amphiphilic bis(tetrathiafulvalene) [bis(TTF)] macrocycles with four alkyl chains were fabricated as novel electrically active Langmuir-Blodgett (LB) films. Two TTF units were linked via [24]crown-8, [21]crown-7, and [18]crown-6 macrocycles, forming charge-transfer (CT) salts with 2,3,5,6-tetrafluor...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1991. - 20(2004), 10 vom: 11. Mai, Seite 4187-95 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2004
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Amphiphilic bis(tetrathiafulvalene) [bis(TTF)] macrocycles with four alkyl chains were fabricated as novel electrically active Langmuir-Blodgett (LB) films. Two TTF units were linked via [24]crown-8, [21]crown-7, and [18]crown-6 macrocycles, forming charge-transfer (CT) salts with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane (F4-TCNQ) at the air-water interface and on solid substrates. The CT salt of the amphiphilic bis(TTF)-macrocycle having a [24]crown-8 ring system formed a uniform surface morphology on mica. Using single-crystal X-ray structural analysis, the layer structure between the hydrophobic chains and the one-dimensional pi-pi stack of the CT salt was confirmed. Our results show that the bis(TTF)-macrocycle was folded at the flexible [24]crown-8 moiety, forming intramolecular pi-pi dimer structures and one-dimensional intermolecular pi-pi stacks with F4-TCNQ dimers. The open-shell electronic structure of the LB films was determined by electronic spectra, electrical conductivity, and electron spin resonance analyses. Asymmetry was introduced into the bis(TTF)-macrocycle by changing the ring size from [24]crown-8 to [21]crown-7. The surface morphology of the CT salts with F4-TCNQ was established as two-dimensional round-shape domains on mica. Further reduction of the macrocyclic ring from [21]crown-7 to [18]crown-6 resulted in a CT salt of the bis(TTF)-macrocycle with F4-TCNQ with a leaf-shape domain morphology and a typical dimension of approximately 1 microm2 on mica. In general, decreasing the macrocyclic ring size from [24]crown-8 to [21]crown-7 or [18]crown-6 affected the inter- and intramolecular interactions and the surface morphologies of LB films |
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| Beschreibung: | Date Completed 31.01.2006 Date Revised 26.10.2019 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 0743-7463 |