Synthesis, Optical, and Electronic Properties of Soluble Poly-p-phenylene Oligomers as Models for Molecular Wires
A homologous series of soluble poly-p-phenylenes containing up to eight phenylene moieties (PP 2 −PP 8 ) with branched iso-alkyl (or bis-n-alkylmethyl) groups has been synthesized and the structure−property relationship with regards to various optical and electronic properties established. All elect...
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Published in | Journal of the American Chemical Society Vol. 131; no. 5; pp. 1780 - 1786 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
11.02.2009
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | A homologous series of soluble poly-p-phenylenes containing up to eight phenylene moieties (PP 2 −PP 8 ) with branched iso-alkyl (or bis-n-alkylmethyl) groups has been synthesized and the structure−property relationship with regards to various optical and electronic properties established. All electronic and optoelectronic properties of poly-p-phenylenes followed a 1/n relationship (where n is number of phenylene moieties) with the increasing number of phenylene moieties. The low-energy electronic transition of the PP 2 −PP 7 cation radicals, generated either by laser-flash photolysis or by chemical oxidation, varied as well according to the inverse (1/n) relationship. The observed inverse relationship of all measured electronic and optoelectronic properties against the increasing number of phenylene units in various PP n ’s, as well as X-ray crystallography of both neutral and a cation-radical salt of a representative tetra-p-phenylene oligomer allows us to demonstrate that the effective conjugation length in poly-p-phenylenes is, in part, controlled by the increasing number of interactions of ortho hydrogens which may prevent simultaneous planarization of the continuous arrays of a large number of phenylene moieties. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0002-7863 1520-5126 |
DOI: | 10.1021/ja805102d |