Translational isomerism and dynamics in multi-hydroquinone derived porphyrin [2]- and [3]-catenanes
作者:Maxwell J. Gunter、Sandra M. Farquhar、Tyrone P. Jeynes
DOI:10.1039/b308157e
日期:——
isolated as mixtures of atropisomers, where the linking strap spans across the face of the porphyrin (alpha,alpha-isomer), or 'twisted' around its side (alpha,beta-isomer). Their structures were determined by detailed 1H NMR spectroscopy. The bis-1,4-dioxybenzene-strapped derivatives were shown to undergo atropisomerisation on heating, to produce an equilibrium mixture. Catenation under high pressure conditions
为了生产含卟啉的[2]和[3]儿茶酚,已经合成了一系列用含两个或三个1,4-二氧苯单元的聚醚链缠结的卟啉,其中卟啉被缠结在两个邻位之间。 5,15-(间位)-二芳基,并与联吡啶大环环双(百草枯-4,4'-联亚苯基)互连。卟啉被分离为阻转异构体的混合物,其中连接带横跨卟啉的表面(α,α-异构体),或围绕其侧面(α,β-异构体)“扭曲”。通过详细的1H NMR光谱确定其结构。证明双-1,4-二氧苯-封链的衍生物在加热时发生对位异构化,以产生平衡混合物。混合物在高压条件下的链化作用,单个或单个异构体,仅产生单个链烷,即α,α-异构体。其结构通过质谱和动态NMR测量确定。确定速率:(i)1,4-二氧苯之间的平移运动或“穿梭”;(ii)大环绕1,4-二氧苯轴的“旋转”;(iii)大环内1,4-二氧苯的“摇动”。还分离了包含三个1,4-二氧苯单元的带链衍生物的阻转异构体,并进行了串联。分离出[2]-和[3]