A new mesoporous metal-organic framework (MOF; DUT-60) was conceptually designed in silico using Zn O nodes, ditopic and tritopic linkers to explore the stability limits of framework architectures with ultrahigh porosity. The robust ith-d topology of DUT-60 provides an average bulk and shear modulus (4.97 GPa and 0.50 GPa, respectively) for this ultra-porous framework, a key prerequisite to suppress pore collapse during desolvation. Subsequently, a cluster precursor approach, resulting in minimal side product formation in the solvothermal synthesis, was used to produce DUT-60, a new crystalline framework with the highest recorded accessible pore volume (5.02 cm g ) surpassing all known crystalline framework materials.

Switchable metal-organic frameworks change their structure in time and selectively open their pores adsorbing guest molecules, leading to highly selective separation, pressure amplification, sensing and actuation applications. The three-dimensional engineering of metal-organic frameworks has reached a high level of maturity, but spatiotemporal evolution opens a new perspective towards engineering materials in the 4 th dimension (time) by t-axis design, in essence exploiting the deliberate tuning of activation barriers. This work demonstrates the first example in which an explicit temporal engineering of a switchable metal-organic frameworkdeliberately tuned by variation of cobalt content. We present a spectrum of advanced analytical methods for analyzing the switching kinetics stimulated by vapor adsorption using in situ time resolved techniques ranging from ensemble adsorption and advanced synchrotron X-ray diffraction experiments to individual crystal analysis. A novel analysis technique based on microscopic observation of individual crystals in a microfluidic channel reveals the lowest limit for adsorption switching reported so far. The time constants for the bulk ensembles range from 2 -300 s. Differences in spatiotemporal response of crystal ensembles originate from a delay (induction) time that varies statistically and widens characteristically with increasing cobalt content reflecting increasing activation barriers.

Linker elongation is an important method to systematically adjust porosity and pore size in isoreticular MOFs. In flexible structures, this approach opens the possibility for the systematic analysis of the building blocks and their contribution to the overall flexible behavior enabling tuning of the framework responsivity toward molecular stimuli. In this work, we report two new compounds isoreticular to the highly flexible pillared layer structure DUT-8­(Ni) ([Ni2(2,6-ndc)2(dabco)] n , 2,6-ndc = 2,6-naph­thalene­di­carboxylate, dabco = 1,4-diaza­bicylo­[2.2.2]­octane). Aromatic linker 2,6-ndc was substituted by longer carboxylic linkers, namely, 4,4′-bi­phenyl­di­carboxylate (4,4′-bpdc) and 4,4′-stil­bene­di­carboxylate (4,4′-sdc), while the dabco pillar was retained. The structural response of the new compounds toward the desolvation and adsorption of various fluids was studied using advanced in situ PXRD techniques, demonstrating distinct differences in the flexible behavior of three compounds and disclosing the impact of linker structure on the framework response. Theoretical calculations provide mechanistic insights and an energetic rationale for the pronounced differences in switchability observed. The energetics of linker bending and linker–linker dispersion interactions govern the phase transitions in investigated MOFs.

Guest-responsive crystalline porous frameworks are able to adapt their pore structure and properties upon adsorption and desorption of gases. Herein analyze the switching kinetics of a breathing framework MIL-53(Al) with...

Ein neues mesoporçses metallorganisches Netzwerk (DUT-60) wurde zunächst am Computer aus Zn 4 O 6+ -Knoten sowie ditopen und tritopen Liganden entworfen, um die Stabilitätsgrenzen von Gerüstverbindungen mit ultrahoher Porositätzuuntersuchen. Die robuste ith-d-Topologie von DUT-60 erreicht einen mittleren Kompressions-und Schermodul (4.97 GPau nd 0.50 GPa), eine entscheidende Voraussetzung, um ein Kollabieren der Poren während der Desolvatisierung zu unterdrücken. Hierauf wurdeeine von Clustern ausgehende Route ausgearbeitet, um durch Solvothermalsynthese mit minimaler Nebenproduktbildung das neue kristalline Netzwerk (DUT-60) herzustellen, das mit dem hçchsten jemals gemessenen Porenvolumen (5.02 cm 3 g À1 )alle bekannten kristallinen Netzwerkmaterialien übertrifft.