Coumarin-Annelated Regioisomeric Heptahelicenes: Influence of Helicity on Excited-State Properties and Chiroptical Properties
作者:Arindam Mukhopadhyay、Kanyashree Jana、Tousif Hossen、Kalyanasis Sahu、Jarugu Narasimha Moorthy
DOI:10.1021/acs.joc.9b01126
日期:2019.9.6
structural relaxation in the excited state is shown from theoretical calculations to cause decrease in the fluorescence quantum yield for a system with higher helicity. The optically pure enantiomers of heptahelical coumarins exhibit helicity-dependent chiroptical properties, namely, specific rotations, molar ellipticities, Cotton effects, and anisotropic dissymmetry factors. Theoretical calculations point
两对七异构的七螺旋单和双香豆素,以“向内”和“向外”来区分已经合成并研究了吡喃-2-酮部分的位置,以了解螺旋度对激发态和手性性质的影响。发现在香豆素-退火的庚二烯的激发态性质相反时,螺旋度略有变化。除分子内电荷转移外,理论计算还显示了激发态的结构弛豫,这会导致具有较高螺旋度的系统的荧光量子产率下降。七螺旋香豆素的光学纯对映异构体表现出螺旋依赖性的手性,即比旋光度,摩尔椭圆率,棉花效应和各向异性不对称因素。理论计算指出了不易解释的因素。