Rotational Isomers in Stacked Macrocycles: Synthesis and Spectroscopic Properties of Peripherally Substituted (μ-Oxo)bis(phthalocyaninatosilicon) Compounds
作者:Jörg Kleinwächter、Michael Hanack
DOI:10.1021/ja962663f
日期:1997.11.1
between 560 and 760 nm, and proton NMR spectra show a strong splitting (Δδ = 1 ppm) of the aromatic signal at low temperature, indicating a torsion angle of ∼20−30° between the rings. In aromatic solvents such as, e.g., benzene, toluene, or 1-methylnaphthalene, thermochromism of the dimers is observed. This is shown by temperature-dependent optical absorption spectroscopy to be due to the presence
一系列可溶性八烷氧基取代的硅酞菁单体 (RO)8PcSi(OSiMe2tBu)L 和 μ-氧桥二聚体 [(RO)8PcSi(OSiMe2tBu)]2O (R = H17C8-,报告了 H25C12-、(±)-3,7-Me2-C8H15-、(±)-2-Et-C6H12-;L = -OSiMe2tBu、-OSiMe3、-F、-OH)。所有二聚体的光吸收光谱都显示出强烈的溶剂致变色行为,而单体则没有。在非芳香族溶剂(例如二氯甲烷)中,二聚体的 Q 带在 560 到 760 nm 之间分裂为至少五个宽带,质子 NMR 光谱显示在低芳香族信号强烈分裂(Δδ = 1 ppm)温度,表明环之间的扭转角为~20-30°。在芳族溶剂例如苯、甲苯或1-甲基萘中,观察到二聚体的热致变色。温度相关的光学吸收光谱表明这是由于存在仅存在于芳族溶剂溶液中的第二异构体。它显示了一个...