%0 Journal Article
%A Mayershofer, Martin G.
%A Nuyken, Oskar
%A Buchmeiser, Michael R.
%D 2006
%T Bi- and Trinuclear Ruthenium Alkylidene Triggered
Cyclopolymerization of 1,6-Heptadiynes: Access to An−X−An Block
and (An)3X Tristar Copolymers
%U https://acs.figshare.com/articles/journal_contribution/Bi_and_Trinuclear_Ruthenium_Alkylidene_Triggered_Cyclopolymerization_of_1_6_Heptadiynes_Access_to_A_i_sub_n_sub_i_X_A_i_sub_n_sub_i_Block_and_A_i_sub_n_sub_i_sub_3_sub_X_Tristar_Copolymers/3222124
%R 10.1021/ma052510p.s001
%2 https://acs.figshare.com/ndownloader/files/5056051
%K trinuclear metathesis catalysts
%K Trinuclear Ruthenium Alkylidene Triggered Cyclopolymerization
%K parent block copolymer
%K ester
%K IMesH
%K OH
%K OOCCF 3
%K 3 X type tristar copolymers
%K RuX
%K CF 3 COOAg
%K M 2 25
%K CH
%K Cl
%K dipropargylmalonate
%K acid
%K initiator
%X Benzoic acid (4-(2-propoxy)-3-vinylphenyl) ester (1), the divinyl compounds terephthalic acid bis(4-(2-propoxy)-3-vinylphenyl) ester (2) and bis(4-(2-propoxy)-3-vinylphenoxy)diphenylsilane (3), and the trivinyl
compound benzene-1,3,5-tricarboxylic acid tris(4-(2-propoxy)-3-vinylphenyl) ester (4) were used for the synthesis
of a series of ruthenium-based mono-, bi-, and trinuclear metathesis catalysts, i.e., RuX2(IMesH2)(CH-2-(2-PrO)-C6H3-5-OOCC6H5) (X = Cl, I1a; X = OOCCF3, I1b), 1,4-[RuX2(IMesH2)(CH-2-(2-PrO)-C6H3-5-OOC)]2C6H4 (X = Cl, I2a; X = OOCCF3, I2b), [RuX2(IMesH2)(CH-2-(2-PrO)-C6H3-5-O)]2SiPh2 (X = Cl,
I3a; X = OOCCF3, I3b), and 1,3,5-[RuX2(IMesH2)(CH-2-(2-PrO)-C6H3-5-OOC)]3C6H3 (X = Cl, I4a; X =
OOCCF3, I4b) (IMesH2 = 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene), where the corresponding trifluoroacetate-derived systems were prepared from the parent dichloro-substituted initiators via reaction with CF3COOAg.
Initiators I1a−I4a and I1b−I4b were used for the cyclopolymerization of a series of 1,6-heptadiynes, i.e., dimethyl
dipropargylmalonate (M1), diethyl dipropargylmalonate (M2), di-tert-butyl dipropargylmalonate (M3), 4-(ethoxycarbonyl)-1,6-heptadiyne (M4), 4,4-(bishydroxymethyl)-1,6-heptadiyne (M5), and 4-(hydroxymethyl)-1,6-heptadiyne (M6), to yield the corresponding An−X−An type block and (An)3X type tristar copolymers. Cleavage of
the An−X−An type block copolymer M225−CH-[2-(2-PrO)-1,5-C6H3]-O-SiPh2-O-[2-(2-PrO)-1,5-C6H3]-CH-M225
with tetrabutylammonium fluoride resulted in the formation of the low-PDI telechelic homopolymer M225-CH-[2-(2-PrO)-1,5-C6H3]-OH with half the molecular weight of the parent block copolymer, indicative for an equal
activity of both initiator sites in I3b. An interesting finding was the fact that monomers with reduced steric
demands in the 4-position (M1, M4, M5, and M6) could even be polymerized with chlorine-based initiators;
however, values for Mn were in general lower than the calculated ones. In contrast to Mo-based initiators, no
influence of monomer size on the structure of the final polymer in terms of the ratio of 1,2-(cyclopent-1-ene)vinylene and 1,3-(cyclohex-1-ene)methylidene units, respectively, was observed.
%I ACS Publications