Thorpe-Ingold effect on the helicity of chiral alternating silylene-divinylarene copolymers.
The concept of the Thorpe-Ingold effect has been used to rationalize the helicity of the silylene-spaced divinylarene copolymers having chiral substituents. Diisopropylsilylene-spaced divinylbenzene copolymers having chiral 2-methylbutoxy substituents have been shown to exhibit a helical conformation. The presence of the bulky isopropyl substituents on silicon would render each of the monomeric units in these copolymers to favor a syn-syn conformation. The copolymer would thus be more folded to form helical morphology as revealed by the notable enhancement of the circular dichroic intensity. The reversible temperature-dependent circular dichroism (CD) profiles further support the stable helical conformation for the copolymers 4 b and 5 b.
Yeh
Mei-Yu
MY
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Luh
Tien-Yau
TY