Sue Andrew C-H, Mannige Ranjan V, Deng Hexiang, Cao Dennis, Wang Cheng, Gándara Felipe, Stoddart J Fraser, Whitelam Stephen, Yaghi Omar M
Department of Chemistry, University of California, Berkeley, and Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Chemistry, Northwestern University, Evanston, IL 60201;
Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; and.
Proc Natl Acad Sci U S A. 2015 May 5;112(18):5591-6. doi: 10.1073/pnas.1416417112. Epub 2015 Apr 21.
Multiple organic functionalities can now be apportioned into nanoscale domains within a metal-coordinated framework, posing the following question: how do we control the resulting combination of "heterogeneity and order"? Here, we report the creation of a metal-organic framework, MOF-2000, whose two component types are incorporated in a 2:1 ratio, even when the ratio of component types in the starting solution is varied by an order of magnitude. Statistical mechanical modeling suggests that this robust 2:1 ratio has a nonequilibrium origin, resulting from kinetic trapping of component types during framework growth. Our simulations show how other "magic number" ratios of components can be obtained by modulating the topology of a framework and the noncovalent interactions between component types, a finding that may aid the rational design of functional multicomponent materials.
现在可以将多种有机官能团分配到金属配位框架内的纳米级区域中，这就提出了一个问题：我们如何控制由此产生的“异质性和有序性”的组合？在此，我们报告了一种金属有机框架MOF-2000的合成，即使起始溶液中组分类型的比例变化了一个数量级，其两种组分类型仍以2:1的比例掺入。统计力学模型表明，这种稳健的2:1比例具有非平衡起源，是框架生长过程中组分类型的动力学捕获所致。我们的模拟展示了如何通过调节框架的拓扑结构和组分类型之间的非共价相互作用来获得其他“神奇数字”比例的组分，这一发现可能有助于功能性多组分材料的合理设计。
