Acyclic diene metathesis (ADMET) polymerization: synthesis of unsaturated polyethers

Abstract

Previously unknown unsaturated polyethers from acyclic, ether-containing dienes have first been obtained via acyclic diene metathesis (ADMET) polymerization in the presence of the catalyst W(CHt-Bu) (N-2,6-CsHs-i-Pr~) [OCMe(CFs)2]2. Polymer yields are high, and number-average molecular weights up to an = 15 000-18 OOO are observed. Structural assignments of the polymers are based on 1% NMR and 1H NMR spectroscopy, IR spectroscopy, and elemental analysis. The polymerizability of the ether-containing a,o-diene appears to be a function of the distance between the ether oxygen and the metathesizing double bond in the monomer. An ether-containing diene has also been copolymerized with 1,9-decadiene.

Poly(p-phenylene alkylene)s – A forgotten class of polymers

“…With the latter, perfectly linear 1,4-polybutadiene 141) , as well as polymers [142][143][144] and copolymers 145,146) of 1,5-hexadiene and 1,9-decadiene with number-average molecular weights, M -n , up to 57 000 142) were synthesized. In addition to the relatively high molecular weights and the readily available monomers, ADMET polymerization proved to be a viable synthetic route to polymers, possessing various functionalities such as ethers 147) , thioethers 148) , silanes 149) , siloxanes 150) , esters 151) , ketones 152) , carbonates 153) , amines 154) , boronates 155) , stannanes 156) , and alcohols 157) . A synthetic route for poly(p-phenylene alkylene)s employing this methodology is, thus, suggested in Scheme 3 f.…”

“…Molecular-weight data were obtained using 1 H NMRendgroup analysis for oligomers and gel permeation chromatography (GPC) for polymers. The weight-average molecular weights, M -w , obtained with ADMET are in the range of 13 000 -25 000 g/mol, with polydispersities of typically between 2 and 3, and are, thus, in the typical molecular-weight regime obtained from ADMET reactions 142,146,147,151,161) . The molecular weights of PPPOs prepared by Suzuki cross-coupling were significantly lower; the maximum number-average molecular weights obtained were around 3 200 g/mol.…”

Synthesis of poly(sulfonate ester)s by ADMET polymerization

“…39 This effect generally occurs when fewer than two methylene spacers separate the coordinating group and the alkene, and it has been observed for a wide variety of functional groups, including ethers, 23 thioethers, 25 phosphates, 29 esters, 24 and carbonates. 26 With the aim of circumventing this potential problem, three different sulfonate ester-containing α,ω-diene monomers were synthesized, M1-M3, in which the sulfonate ester group was separated from the alkene with m = 2, 4, and 9 methylene groups, respectively.…”

“…18,19 Unlike the related ring-opening metathesis polymerization (ROMP), which is a chain-growth process driven by the release of ring strain, ADMET is driven by the removal of the ethylene gas generated as a by-product. ADMET chemistry has been used recently in the synthesis of both all-carbon polyolefins [20][21][22] as well as polyethylene-like polymers containing heteroatoms [23][24][25][26][27][28][29] or aromatic rings [30][31][32] in the main chain. ADMET offers an interesting alternative for the incorporation of aliphatic sulfonate esters into the polymer backbone, which are rare in the literature.…”

Morphology control in precision polyolefins

“…As ring-strain in the monomer is not required, a wide variety of diene monomers is possible. ADMET has been used to produce polymers containing simple hydrocarbons [3,4], aromatic amines [5], branched acids [6,7], ethers [8,9], silanes [10], acetals [11], esters [12][13][14][15], aromatic moieties [16][17][18][19][20], thioethers [21], and ketones [14,22], to name a few.…”