Influence of halogen substituents on the self-assembly of oligothiophenes--a combined STM and theoretical approach
Iodinated quaterthiophenes 2-3 have been synthesized and their self-assembling behavior investigated at the liquid-solid interface by means of high-resolution scanning tunneling microscopy in comparison to parent oligothiophene 1. All three compounds spontaneously give well-ordered 2D crystalline mo...
| Publié dans: | Langmuir : the ACS journal of surfaces and colloids. - 1991. - 22(2006), 4 vom: 14. Feb., Seite 1443-8 |
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| Auteur principal: | |
| Autres auteurs: | , , , |
| Format: | Article |
| Langue: | English |
| Publié: |
2006
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| Accès à la collection: | Langmuir : the ACS journal of surfaces and colloids |
| Sujets: | Journal Article |
| Résumé: | Iodinated quaterthiophenes 2-3 have been synthesized and their self-assembling behavior investigated at the liquid-solid interface by means of high-resolution scanning tunneling microscopy in comparison to parent oligothiophene 1. All three compounds spontaneously give well-ordered 2D crystalline monolayers at the graphite surface and order in a lamella-type arrangement of the conjugated backbones concomitant with an interlocking of the alkyl side chains. Symmetrically substituted oligothiophenes 1 and 3 without a relevant dipole moment self-assemble in a similar fashion, exhibiting comparable unit cells, whereas monoiodo derivative 2 arranges as pairs along the lamella axis due to the presence of a permanent dipole moment induced by the polarizable halogen group. Corroborated by quantum chemical calculations, novel head-to-head (iodo-iodo) intermolecular interactions were found to take place for this unsymmetrical derivative. The investigation of mixed solutions clearly reveals that at the solid-liquid interface a homogeneous layer of this compound is formed, which comprises the highest packing density leading to a separation process at the interface |
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| Description: | Date Completed 09.05.2007 Date Revised 07.02.2006 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 0743-7463 |