Poly[(para-halogenated)phenylacetylene]s Prepared with a [Rh(norbornadiene)Cl]2 Catalyst: Syntheses and Structure Elucidation

✍ Scribed by Atsushi Miyasaka; Takeyuki Sone; Yasuteru Mawatari; Sepas Setayesh; Klaus Müllen; Masayoshi Tabata

• Book ID: 102489987
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 133 KB
• Volume: 207
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200600308

✦ Synopsis

Abstract

Summary: pXPAs were stereospecifically polymerized using [Rh(nbd)Cl]~2~ as catalyst in the presence of a mixed solvent, i.e., ethanol and triethylamine, at 20 °C. The resulting PpXPAs were characterized in detail in order to predict geometrical structures concerning cis and trans configurations in the main‐chain CC bonds using ^1^H NMR, laser Raman, XRD, and ESR methods. The data showed that the PpXPAs have an extremely high content of the cis‐transoid form. Immobile unpaired electrons, ca. 1.2–3.1 × 10^17^ spins · g^−1^, called the cis radicals, were found to be stabilized even in the pristine cis PpXPAs. The observed g values of the pristine PpXPAs could be correlated with the spin‐orbit coupling constant ζ of the halogen atom at the para position of the phenyl.

Second derivative ESR spectra of PpIPA observed (a) before and (b) after compression, and the suggested respective structures.

magnified imageSecond derivative ESR spectra of PpIPA observed (a) before and (b) after compression, and the suggested respective structures.