Diphenyl-o-methoxyphenylmethyl methacrylate was polymerized with several organolithium complexes of chiral ligand such as (-)-sparteine (Sp) and (S,S)-(+)-2,3-dimethoxy-l,4-bis(dimethylamino)butane (DDB). (+)-DDB was effective in preparing a polymer of high optical rotation, whereas (-)-Sp only gave oligomers with low optical rotation for the repulsive hindrance between the bulky ester group and the rigid ligand. The optical rotation of the polymer decreased rapidly to a constant value due to the propeller-propeller transition, which has been demonstrated by ~H n.m.r, and circular dichroic spectra.
Посилання на статтю:
Synthesis and propeller-propeller transition of optically active poly(diphenyl-o-rnethoxyphenylmethyl methacrylate) / Bin Yu, Mengxian Ding* and Fosong Wang // Polymer. – 1993. – Vol 34. – P. 3340-3342.