Figure-eight tetrathiaoctaphyrin and dihydrotetrathiaoctaphyrin.
Figure-eight tetrathiaoctaphyrin and dihydrotetrathiaoctaphyrin.
复制标题
图八四硫代八菲林和二氢四硫代八菲林。
作者：
N. Sprutta;L. Latos‐Grażyński
酸催化吡咯与2，5-双（对甲苯基羟甲基）噻吩产生两种新的巨杂卟啉：5，10，15，20，25，30，35，40-octa（p-tolyl）-41，43，45，47-tetrathia[36]octaphyrin（1.1.1.1.1.1.1.1）（S4 OP）和5，10，15，20，25，30，35，40-八（对甲苯基）-二氢-41，43，45，47-四硫杂[38]八卟啉（1.1.1.1.1.1.1.1）（S4 OPH 2）。这些四硫代八卟啉通过二氢化或脱氢过程可相互转化。NOESY实验表明，两种化合物均具有螺旋8字形几何构型，其中S4 OP具有两个噻吩环，S4 OPH 2具有两个吡咯环。8字形四硫代八卟啉的合成暗示了形成螺旋M或P二硫代四吡咯甲烷的预排列过程。P-P或M-M缩合导致8字形分子与分子内环闭合竞争。S4 OP或S4 OPH 2的两个二硫卟啉样口袋作为独立的质子受体。逐步过程产生对称或不对称阳离子物质，这取决于添加的NH质子是偶数还是奇数。二氢四硫代八卟啉在其共轭途径中含有38个π电子，这对应于形式的[4 n + 2] Hückel型π电子公式，这与它们的1H NMR光谱中的适度向阻环电流效应一致。四硫代八卟啉的4 n型π-电子公式解释了剩余的顺向位移。提出了一个数字8的走廊带式运动的整个大环没有一个外消旋步骤的动力学性能的S4 OP帐户。分子在两种简并构型之间穿梭。S4 OP-S4 OPH 2对可以被认为是一种分子元素，它在保留整体8字形几何结构的同时，根据大环氧化态的函数“选择”吡咯或噻吩环作为间隔基。
The acid-catalyzed condensation of pyrrole and 2,5-bis(p-tolylhydroxymethyl)thiophene yields two novel giant heteroporphyrins: 5,10,15,20,25,30, 35,40-octa(p-tolyl)-41,43,45,47-tetrathia[36]octaphyrin(1.1.1.1.1.1.1.1) (S4OP) and 5,10,15,20,25,30,35,40-octa(p-tolyl)-dihydro-41,43,45,47-tetrathia[38]octaphyrin(1.1.1.1.1.1.1.1) (S4OPH2). These tetrathiaoctaphyrins are interconvertible through dihydrogenation or dehydrogenation processes. Both compounds possess helical figure-eight geometry with two thiophene rings for S4OP or two pyrrole rings for S4OPH2 in the ribbon-crossing center as shown by NOESY experiments. The synthesis of the figure-eight tetrathiaoctaphyrin implies a prearrangement process to form helical M or P dithiatetrapyrromethanes. The P-P or M-M condensation leads to the figure-eight molecule in competition with an intramolecular ring closure. Two dithiaporphyrin-like pockets of S4OP or S4OPH2 behave as independent proton acceptors. The stepwise process yields symmetric or asymmetric cationic species that depends on whether an even or odd number of NH protons are added. Dihydrotetrathiaoctaphyrin contains 38 pi electrons in its conjugation pathway, which corresponds to the formal [4n + 2] Hückel type pi-electron formulation that is consistent with a modest diatropic ring current effect in their 1H NMR spectra. The formal 4n type pi-electron formulation for tetrathiaoctaphyrin accounts for the residual paratropic shifts. A figure-eight conveyor-belt-like movement of the whole macrocyclic ring without a racemization step is proposed to account for the dynamic properties of S4OP. The molecule shuttles between two degenerate configurations. A S4OP-S4OPH2 couple may be considered as a molecular element which, while preserving the overall figure-eight geometry, "chooses" pyrrole or thiophene rings as spacers as a function of the macrocyclic oxidation state.