TY - JOUR
T1 - Optically-active hyperbranched poly(n-alkyltriferrocenylsilanes)
T2 - 2. Thermal transition and optical activity
AU - Sun, Qunhui
AU - Tang, Ben Zhong
PY - 1999/8
Y1 - 1999/8
N2 - A class of hyperbranched poly(n-alkyltriferrocenylsilanes) is synthesized and characterized. These polymers have a sterically-crowding induced perturbation to the achiral chromophores resulting in the formation of a negative helix structure or a twisted screw sense of chiralty, therein a fisrt negative Cotton effect, which is arising from the intra-repulsion and twisting behavior of the hyperbranched structure in space. The length of the n-alkyl chain at silicon can effectively encumber the Si atom from the nucleophilic attack to favor the formation of hyperbranched structure. Two transition temperatures, Tg and Tm when the length of alkyl chain at silicon exceeds a certain value (12 carbons).
AB - A class of hyperbranched poly(n-alkyltriferrocenylsilanes) is synthesized and characterized. These polymers have a sterically-crowding induced perturbation to the achiral chromophores resulting in the formation of a negative helix structure or a twisted screw sense of chiralty, therein a fisrt negative Cotton effect, which is arising from the intra-repulsion and twisting behavior of the hyperbranched structure in space. The length of the n-alkyl chain at silicon can effectively encumber the Si atom from the nucleophilic attack to favor the formation of hyperbranched structure. Two transition temperatures, Tg and Tm when the length of alkyl chain at silicon exceeds a certain value (12 carbons).
UR - https://www.scopus.com/pages/publications/0032628797
M3 - Conference article published in journal
AN - SCOPUS:0032628797
SN - 0032-3934
VL - 40
SP - 657
EP - 658
JO - American Chemical Society, Polymer Preprints, Division of Polymer Chemistry
JF - American Chemical Society, Polymer Preprints, Division of Polymer Chemistry
IS - 2
ER -