Synthesis, Structure and Properties of Bridged and Unbridged Heterohelicenes
作者:Kazuhiko Tanaka、Yoshinori Kitahara
DOI:10.1080/10426509908546490
日期:1999.1
The structure of a bridged thiaheterohelicene has been determined by X-ray crystallographic method, showing that the helicene framework exhibits significant elasticity and acts as a molecular spring.
通过X射线晶体学方法确定了桥接硫杂杂螺旋烯的结构,表明螺旋骨架具有显着的弹性并充当分子弹簧。
Elongation and Contraction of Molecular Springs. Synthesis, Structures, and Properties of Bridged [7]Thiaheterohelicenes
A series of bridged [7]thiaheterohelicenes 3a-c and 4 with a variety of helical pitches have been prepared from racemic and optical pure 2,13-bis(hydroxymethyl)dithieno[3,2-e:3',2'-e']benzo[1,2-b:4,3-b']bis[1]benzothiophene (1) in order to investigate the helical structures in solution. Recrystallizations of (PM)-3a, (PM)-3b, (PM)-3c, and (P)-4 from hexane-dichloromethane gave crystals suitable for
Enantiomeric helicenes of (P)-A and (M)-A were synthesized. The binding of the helicenes to B- and Z-DNA was studied quantitatively by CD, equilibrium dialysis, and fluorescence spectroscopy. Enantiomeric (P)-A not only bound selectively to Z-DNA but also effectively converted the B-DNA conformation to Z-DNA. The enantioselectivity of the helicenes offers a new route for the rational design of inhibitors of biological functions that may depend on Z-DNA.