Polymerization of Diphenylacetylenes with Polar Functional Groups by the Grubbs–Hoveyda Ru Carbene Catalyst

Abstract

Summary: Polymerization of various diphenylacetylene derivatives was investigated by using Grubbs–Hoveyda catalyst (1). Owing to excellent tolerance for polar functional groups, catalyst 1 polymerized diphenylacetylene (2) and diphenylacetylene derivatives bearing silyl (3), siloxy (4 and 5), ester (6 and 7), amide (8–10), and carbamate (11) groups. It is noteworthy that polymerization of monomers 6–11, which have polar functional groups, has been impossible until now due to the deactivation of well‐known Ta catalysts. Although monomers having ester groups (6 and 7) hardly polymerized, their copolymerization with trimethylsilyl group‐containing diphenylacetylene (3) afforded copolymers, which incorporated ester moieties more than the monomer feed ratio. While polymers with relatively nonpolar groups [poly(3)–poly(5)] were soluble in hydrocarbon solvents such as cyclohexane and hexane, polar group‐bearing homo‐ and copolymers (poly(10), poly(11), etc.) dissolved in polar solvents (e.g., DMF and acetone). Polymerization of 1‐(4‐tert‐butyldimethylsiloxy)phenyl‐2‐(4‐fluorophenyl)acetylene (5) gave a high molecular weight polymer ($\overline M _{\rm n}$ = 178 000) suitable for membrane fabrication, and the membrane of this polymer showed higher gas permeability and permselectivity than that of the Ta‐based polymer.Polymerization of various diphenylacetylenes by the Ru Grubbs–Hoveyda catalyst.magnified imagePolymerization of various diphenylacetylenes by the Ru Grubbs–Hoveyda catalyst.

Polymerization of hydroxyacetylenes by ruthenium alkylidene complexes

“…This indicates that the conjugation length of the polymers prepared in the presence of Ru catalysts is much shorter than those of the polymers obtained in the Mo-based one. Analogous tendency was observed by Masuda et al for the Ta-and Ru-based polymers of diphenylacetylene derivatives bearing silyl and siloxy groups [25,26].…”

“…The 2nd generation Grubbs-Hoveyda complex has been reported as catalyst capable of polymerizing mono-and disubstituted acetylenes bearing non-polar and polar groups such as ester, amide etc. [25,26]. However, polymerization of acetylenes containing polar hydroxyl groups in the presence of well-defined complexes was not examined.…”

Current operator volumes of invasive coronary procedures in medicare patients: Implications for future manpower needs in the catheterization laboratory

“…For the synthesis of substituted polyacetylenes, a great deal of effort has been made to develop well‐controlled polymerization systems, because it contributes the investigation of their unique properties as polymeric materials derived from the stiff conjugated main chain with a variety of pendant groups 1–3. Fully characterized transition metal catalysts composed of Ta,4 Mo,5–8 W,9, 10 Ru,11–16 Rh,17–22 and Pd23, 24 can provide fine control of polymer structure due to determined polymerization mechanism base on the structures of the catalysts. For instance, certain metal carbene complexes polymerize substituted acetylenes via the metathesis mechanism and even achieve living polymerization 4–8.…”

SEC/DAD and1H NMR Study of Molecular Weight and Configurational Stability of Poly(2,4-difluorophenylacetylene) and Polyphenylacetylene Prepared with Rh Catalyst

“…[12,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] The most effective tool for preparation of high-molecular-weight substituted polyacetylenes is the chain coordination polymerization of corresponding acetylenic monomers with transition metal catalysts (Ta and Nb catalysts for the polymerization of disubstituted monomers with bulky substituents, W for less bulky disubstituted monomers and W, Mo, Ni, Ru, Pd and particularly Rh catalysts for the polymerization of monosubstituted ones). [16,22,27,[32][33][34][35][36][37][38] In the case of monosubstituted polyacetylenes, the type of catalyst applied for synthesis usually governs the configurational structure of prepared polymers. [16,39] Rh catalysts, which were shown to operate in the insertion propagation mode, give highly stereoregular, head-to-tail cis-transoid polyacetylenes [27,[40][41][42][43][44][45] denoted as ''high-cis'' polyacetylenes.…”