Butane-1,4-diyl dications stabilized by steric factors: electrochiroptical response systems based on reversible interconversion between dihydro[5]helicene-type electron acceptors and electron-donating 1,1′-binaphthyls
作者:Eisuke Ohta、Hiroki Higuchi、Hidetoshi Kawai、Kenshu Fujiwara、Takanori Suzuki
DOI:10.1039/b506435j
日期:——
Incorporation in the dihydro[5]helicene framework prevents deprotonation of the title dications by steric factors, thus allowing their isolation as deeply colored stable salts. Based on the reversible interconversion with the electron-donating binaphthylic diolefins, they constitute a new class of electrochromic systems, in which CâC bond making/breaking is accompanied by two-electron transfer. Optically pure (R)-binaphthylic donors are interconvertible with the 1,4-dications with the R,R-configuration. The very large molar ellipticity makes it possible for them to be used as electrochiroptical response systems, by which the electrochemical input is transduced into two spectral outputs, i.e. UV-Vis and circular dichroism. Structurally related pushâpull-type bis(quinonemethide)s also exhibit a similar multi-output electrochemical response.
在二氢[5]螺旋烯框架中的结合可防止标题中的二阳离子因空间因素而失去质子,从而使其作为深色稳定盐被分离出来。基于与电子给体二萘基二烯烃的可逆互转化,它们构成了一类新的电致变色系统,其中C-C键的生成/断裂伴随着双电子转移。光学纯(R)-二萘基给体可与具有R,R构型的1,4-二阳离子互转化。非常大的摩尔椭圆度使其可用作电致旋光响应系统,通过该系统,电化学输入被转换为两种光谱输出,即紫外-可见光和圆二色性。结构上相关的推-拉型双(醌甲酰)也表现出类似的多输出电化学响应。