Zinc-1,4-benzenedicarboxylate-bipyridine frameworks – linker functionalization impacts network topology during solvothermal synthesis
作者:Sebastian Henke、Andreas Schneemann、Shobhna Kapoor、Roland Winter、Roland A. Fischer
DOI:10.1039/c1jm14791a
日期:——
Substitution of 1,4-benzenedicarboxylate (bdc) with additional alkoxy chains is the key to construct a family of metalâorganic frameworks (MOFs) of the type [Zn2(fu-bdc)2(bipy)]n (fu-bdc = functionalized bdc; bipy = 4,4â²-bipyridine) exhibiting a honeycomb-like topology instead of the default pillared square-grid topology. Both the substitution pattern of the phenyl ring of the fu-bdc linker and the chain length of the alkoxy substituents have a major impact on the structure of the derived frameworks. Substitution at positions 2 and 3 leads to the trivial pillared square-grid framework, and substitution at positions 2 and 5 or 2 and 6 yields MOFs with the honeycomb-like topology. Also, simple methoxy substituents lead to the construction of a pillared square-grid topology, whereas longer substituents like ethoxy, n-propoxy, and n-butoxy generate honeycomb-like framework structures. These honeycomb MOFs feature one-dimensional channels, which are tuneable in diameter and functionality by the choice of substituent attached to the bdc-type linker. Pure component sorption isotherms indicate that the honeycomb-like frameworks selectively adsorb CO2 over N2 and CH4.
用额外的烷氧基链取代 1,4-苯二甲酸 (bdc) 是构建 [Zn2(fu-bdc)2(bipy)]n (fu-bdc) 类型金属有机框架 (MOF) 家族的关键= 功能化 bdc;bipy = 4,4-联吡啶)呈现出蜂窝状拓扑结构,而不是默认的柱状方形网格拓扑结构。 fu-bdc 连接体苯环的取代模式和烷氧基取代基的链长对衍生框架的结构有重大影响。在位置 2 和 3 处进行替换会产生普通的柱状方格网格框架,在位置 2 和 5 或 2 和 6 处进行替换会产生具有蜂窝状拓扑的 MOF。此外,简单的甲氧基取代基导致构建柱状方形网格拓扑,而较长的取代基如乙氧基、正丙氧基和正丁氧基则产生蜂窝状框架结构。这些蜂窝状 MOF 具有一维通道,可通过选择连接到 bdc 型连接体的取代基来调节直径和功能。纯组分吸附等温线表明,蜂窝状框架选择性地吸附 CO2 而不是 N2 和 CH4。