Rhodium and platinum complexes as catalysts for the polymerization of phenylacetylene

Abstract

In polymerization reactions of phenylacetylene three different types of polyphenylacetylene (PPA) were prepared by using Rh and Pt complexes as catalysts in different reaction conditions. Type I PPA is obtained with [Rh (COD) Chel] PF6 complexes (COD = cis,cis‐cycloocta 1,5‐diene; chel = 2,2′‐bipyridine, 1,10‐phenanthroline, 2,9‐dimethyl‐1,10‐phenanthroline, 5,6‐dimethyl‐1,10‐phenanthroline, 3,4,7,8‐tetramethyl‐1,10‐phenanthroline) in bulk, benzene methanol, while type II PPA is obtained with the same catalysts in p‐dioxane and type III PPA in the presence of [Pt (CCPh)2(PPh3)2] in bulk. Type I, II, and III PPA exhibit different IR and 1H‐NMR spectra, which have been compared with literature data. Correlations proposed by different Authors between spectral properties of PPA and chain structures are also discussed.

Synthesis of novel mono-substituted polyacetylenes bearing functional urea groups in side chains

“…made large contribution to the development of the effective catalysts. When functionality-tolerant rhodium-based catalysts [25] were used, the resulting polyacetylenes generally possessed high stereo-regularity, i.e., cis contents are nearly 100% [26]. Herein, Rh-based catalyst, (nbd)Rh + B À (C 6 H 5 ) 4 was employed to conduct the polymerizations (Scheme 2).…”

Polymerization of phenylacetylene by novel Rh (I)-, Ir (I)- and Ru (IV) 1,3-R2-3,4,5,6-tetrahydropyrimidin-2-ylidenes (R=mesityl, 2-propyl): Influence of structure on activity and polymer structure

“…The 1 H NMR signal at d = 5.84 was characteristic for double bonds in cis-transoid sequences. The cis-content of the corresponding polymers was quantified according to the established equation: %-cis = 100 · (A 5.84 · 6)/(A total ), data are summarized in Table 4 [38]. Polymerization of PA with the cationic complex 1 in chlorinated solvents at either room temperature, 40 and 80°C, respectively, resulted in the formation of PPA with 70-80% cis-content (Table 4, entries 1-3).…”

Microstructure and morphology of polyphenylacetylene prepared in compressed carbon dioxide

“…Generally, PPA has two absorption bands at 740 and 760 cm À1 and the content of cis and trans units has been evaluated by the ratio of the intensities of the two bands. [5][6][7] The trans-rich PPA shows no absorption at 740 cm À1 , but shows absorption at 760 cm À1 . On the other hand, cis-rich PPA shows both absorption bands, and a higher stereoregularity (cis content) results in higher intensity of the band at 740 cm À1 .…”