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Precise synthesis of monosubstituted polyacetylenes using Rh complex catalysts. Control of solid structure and π‐conjugation length
Author(s) -
Tabata Masayoshi,
Sone Takeyuchi,
Sadahiro Yoshikazu
Publication year - 1999
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/(sici)1521-3935(19990201)200:2<265::aid-macp265>3.0.co;2-6
Subject(s) - norbornadiene , chemistry , isomerization , polymerization , triethylamine , raman spectroscopy , photoisomerization , catalysis , photochemistry , yield (engineering) , polymer chemistry , solvent , polymer , intramolecular force , mealybug , crystallography , stereochemistry , organic chemistry , materials science , physics , business , marketing , pest analysis , optics , metallurgy
Stereospecific polymerization of monosubstituted acetylenes was successfully performed using a Rh complex, [Rh(norbornadiene)Cl] 2 , as a catalyst, and the resulting polyacetylenes were characterized in detail by 1 H NMR, ESR, laser Raman, diffuse reflective UV, and wide‐angle X‐ray diffraction. The Rh complex was found to yield selectively the cis‐transoid isomer even at room temperature in high yields when alcohol or triethylamine was used as the solvent. Additionally, the resulting cis ‐polyacetylenes were found to form a pseudohexagonal, columnar self‐assembly or superstructure. Further compression of the cis ‐polymers induced cis ‐ trans isomerization even at room temperature under vacuum, breaking rotationally the cis ‐C=C bonds and, thus, giving π‐radicals as the origin of magnetic properties.