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On the chirality of polyvinyl compounds, part 17 . Investigations on main‐chain chiral copolymers with alternating structure
Author(s) -
Wulff Günter,
Krieger Stephan
Publication year - 1994
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1994.021951114
Subject(s) - copolymer , styrene , polymer chemistry , methyl methacrylate , triad (sociology) , chirality (physics) , chemistry , materials science , organic chemistry , polymer , psychology , chiral symmetry breaking , physics , quantum mechanics , psychoanalysis , nambu–jona lasinio model , quark
3,4‐ O ‐Cyclohexylidene‐D‐mannitol 1,2:5,6‐bis‐ O ‐[(4‐vinylphenyl)boronate] ( M 1 ) was copolymerized with methyl methacrylate (MMA) in presence of AlEt 1,5 or SnCl 4 . The expected alternating bis(4‐vinylphenylboronic acid)‐MMA triad structures were only formed to a lesser extent. Instead, predominantly alternating 4‐vinylphenylboronic acid‐MMA structures were obtained. Since no crosslinking was observed, a cyclocopolymerization must have occurred. In this case an MMA unit is inserted between the two styrene residues of M 1 , thus forming a 21‐membered ring system. Copolymerization forming alternating 4‐vinylphenylboronic acid‐MMA diads is apparently even faster than the direct copolymerization forming distyryl diads. After removal of the template (3,4‐ O ‐cyclohexylidene‐D‐mannitol), these copolymers still show pronounced optical activity and circular dichroism with a negative Cotton effect at 233 nm. After deboronation of the copolymers, optically active, predominantly alternating styrene‐MMA copolymers are obtained.