Synthesis, stereochemistry, and photochemical and thermal behaviour of bis-tert-butyl substituted overcrowded alkenes
作者:Matthijs K. J. ter Wiel、Marcin G. Kwit、Auke Meetsma、Ben L. Feringa
DOI:10.1039/b611070c
日期:——
In order to study the structural limits in the design of molecular motors, a tert-butyl substituted analogue was prepared. The unexpected photochemical and thermal isomerisation processes and the stereochemistry of new overcrowded alkene are described. The bis tert-butyl substituted alkenes were synthesised in a five-step sequence with an overall yield of 7.5%. Structural assignments of the isomers
Fine Tuning of the Rotary Motion by Structural Modification in Light-Driven Unidirectional Molecular Motors
作者:Javier Vicario、Martin Walko、Auke Meetsma、Ben L. Feringa
DOI:10.1021/ja058303m
日期:2006.4.1
The introduction of bulky substituents at the stereogeniccenter of light-driven second-generation molecular motors results in an acceleration of the speed of rotation. This is due to a more strained structure with elongated C=C bonds and a higher energy level of the ground state relative to the transition state for the rate-limiting thermal isomerization step. Understanding the profound influence