One-Pot Synthesis of Poly(vinyl alcohol) (PVA) Copolymers via Ruthenium Catalyzed Equilibrium Ring-Opening Metathesis Polymerization of Hydroxyl Functionalized Cyclopentene

Abstract

Well-defined poly(vinyl alcohol-alt-propenylene) (4) was synthesized in one-pot reaction via equilibrium ring-opening metathesis polymerization (ROMP) or acyclic diene metathesis (ADMET) of nonprotected 3-cyclopentene-1-ol ( 2) and 1,6-heptadiene-4-ol using (1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium ( 6) and (1,3bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(oisopropoxyphenylmethylene)ruthenium ( 7) metathesis catalysts. The activation enthalpy and entropy of the equilibrium ROMP were determined as ΔH = −6.2 kcal mol −1 and ΔS = −18.9 cal mol −1 K −1 . The observed thermodynamic parameters were supported by computational studies. The calculated ring strain energy for 2 (−6.8 kcal mol −1 ) is comparable with the observed activation enthalpy for its equilibrium ROMP reaction catalyzed by 6 or 7. The cis:trans olefinic bond ratio analysis indicated a 20:80 cis:trans selectivity. The hydrogenation of 4 resulted in poly(vinyl alcohol-alt-propylene) (11) in high yield. Because of the similar ring strain energies of cyclopentene (1) and 2, the equilibrium copolymerization results in a polymer having randomly distributed dyads. In general, it means that the polymer formed contains approximately 50% alternating polymer, 25% 3, and 25% 4 homopolymer dyads as expected for a random polymerization.

A Precision Ethylene‐Styrene Copolymer with High Styrene Content from Ring‐Opening Metathesis Polymerization of 4‐Phenylcyclopentene

“…Linear regression analysis was performed to determine, Δ H = −5.1 kcal mol −1 and Δ S 0 = −19.1 cal mol −1 K −1 for 4PCP under these conditions (Supporting Information). These values are similar to those observed for ROMP of cyclopentene (Δ H = −5.6 kcal mol −1 and Δ S 0 = −18.5 cal mol K −1 ) and 3‐cyclopenten‐1‐ol (Δ H = −6.2 kcal mol −1 and Δ S 0 = −18.9 cal mol −1 K −1 ) recently reported using similar catalysts.…”

“…Following hydrogenation, a precision ES copolymer with a phenyl branch at every fifth carbon (71.2% w/w S) is obtained. This study was motivated by recent success on the polymerizability of cyclopentene and other substituted cyclopentene derivatives through ruthenium‐based ROMP …”

Ring opening metathesis polymerization (ROMP) of five‐ to eight‐membered cyclic olefins: Computational, thermodynamic, and experimental approach

“…On prolonged reaction times (60 min), the monomer conversion for Cy5 did not significantly change (79%), while full conversion (99%) was achieved for Cy7 . As demonstrated by thermodynamic studies from our group and others, the affect can be attributed to the ROMP of Cy5 , which involves a monomer/polymer equilibrium. The results clearly indicate the effect of the monomer concentration on the outcome of the results, which DFT calculation does not take into account.…”

“…In our previous work, we have reported one‐pot polymerization of cyclopentene and its hydroxyl functionalized derivative using well‐defined Ru catalysts . Building upon this work, we investigated (a) ROMP of different ring size cyclic olefins, (b) effect of temperature and monomer concentration for the cyclic olefins Cy5 and Cy7 , (c) influence of the solvent on conversion, and (d) DFT modeling highlighting some of the chlorine to OH interaction adduct when varying the ring size.…”

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2014

“…84) and cyclohexene (copolymer) [378]; (3) cyclopentenes (e.g. 86) in an equilibrium polymerization process [379]; (4) cyclooctene or substituted cyclooctene derivatives [380,381,382,383]; (5) 1,5-cyclooctadiene [384,385]; (6) the 1,5-cyclooctadiene anthracene Diels-Alder adduct (e.g. 87) [386]; (7) cyclooctene fused to a dichlorocyclopropane ring (e.g.…”