Metal-Assembled Cobalt(II) Resorc[4]arene-Based Cage Molecules That Reversibly Capture Organic Molecules from Water and Act as NMR Shift Reagents

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• 作者：O. Danny Fox ; Jenny F.-Y. Leung ; Jesse M. Hunter ; N. Kent Dalley ; and Roger G. Harrison
• 刊名：Inorganic Chemistry
• 出版年：2000
• 出版时间：February 21, 2000
• 年：2000
• 卷：39
• 期：4
• 页码：783 - 790
• 全文大小：175K
• 年卷期：v.39,no.4(February 21, 2000)
• ISSN：1520-510X

文摘

The complex Co₄1₂^8- is a tetranuclear cobalt(II) cage compound that assembles in aqueous solutions above pH4 and is capable of encapsulating a variety of organic guest molecules, for example, benzene, hexane, chlorobutane,butanol, and ethyl acetate. Ligand 1 is a resorc[4]arene-based molecule with iminodiacetate moieties appended toits upper rim. ¹H NMR studies of Co₄1₂^8-·guest complexes demonstrate inclusion of nonpolar hydrocarbons,substituted phenyls, alcohols, halogen-containing hydrocarbons, and polar organic molecules. The complex Co₄1₂^8-acts as an NMR shift reagent and causes substantial upfield isotropic hydrogen shifts (-30 to -40 ppm) in theguest molecule and separation of the guest hydrogen chemical shifts by typically 12 ppm. The complex Co₄1₂^8-will encapsulate molecules with fewer than eight atoms in a linear chain, mono- and disubstituted benzenes, andpolar molecules with greater than two carbon atoms. The solid-state structure of Ba₄[Co₄1₂·C₆H₅C₂H₅] shows adisordered guest molecule encapsulated within the cavity of Co₄1₂^8-. The cavity dimensions, bond lengths, andbond angles of Ba₄[Co₄1₂·C₆H₅C₂H₅] are very similar to those determined in Ba₄[Co₄1₂·6H₂O].