Corresponding states interpretation of adsorption in gate-opening metal-organic framework Cu(dhbc)₂(4,4'-bpy).

The "universal adsorption theory" (UAT) extends the principle of corresponding states for gas compressibility to describe the excess density of an adsorbed phase at comparable reduced conditions. The UAT helps to describe experimental trends and provide predictive capacity for extrapolation from one adsorption isotherm to that of a different adsorbate. Here, we extend the UAT to a flexible metal-organic framework (MOF) as a function of adsorbate, temperature, and pressure.

A systematic study of fluorescence-based detection of nitroexplosives and other aromatics in the vapor phase by microporous metal-organic frameworks.

A systematic study is conducted on four microporous metal-organic framework compounds built on similar ligands but different structures, namely [Zn3(bpdc)3(bpy)]·4DMF·H2O (1), [Zn3(bpdc)3(2,2'dmbpy)]·4DMF·H2O (2), [Zn2(bpdc)2(bpe)]·2DMF (3), and [Zn(bpdc)(bpe)]·DMF (4) (bpdc=4,4'-biphenyldicarboxylate; bpy=4,4'-bipyridine; 2,2'dmbpy=2,2'-dimethyl-4,4'bipyridine; bpe=1,2-bis(4-pyridyl)ethane; DMF=N,N'-dimethylformamide) to investigate their photoluminescence properties and sensing/detection behavior upon exposure to vapors of various aromatic molecules (analytes) including nitroaromatic explosives. The results show that all four compounds are capable of detecting these molecules in the vapor phase through fluorescence quenching or enhancement. Both electrochemical measurements and theoretical calculations are performed to analyze the analyte-MOF interactions, to explain the difference in signal response by different analytes, and to understand the mechanism of fluorescence quenching or enhancement observed in these systems.

A new layered metal-organic framework as a promising heterogeneous catalyst for olefin epoxidation reactions.

A new layered MOF material [Co(Hoba)(2)·2H(2)O] (1) (H(2)oba = 4,4'-oxybis(benzoic acid)) has been synthesized and used as a highly recyclable heterogeneous catalyst for olefin epoxidation reactions. Both high conversion (96%) and high selectivity of epoxide products (96%) are achieved.

New microporous metal-organic framework demonstrating unique selectivity for detection of high explosives and aromatic compounds.

A highly luminescent three-dimensional microporous metal-organic framework, [Zn(2)(oba)(2)(bpy)]·DMA, demonstrates unique selectivity for the detection of high explosives and other aromatics via a fluorescence quenching and enhancement mechanism.

The nature of surface barriers on nanoporous solids explored by microimaging of transient guest distributions.

Nanoporous solids are attractive materials for energetically efficient and environmentally friendly catalytic and adsorption separation processes. Although the performance of such materials is largely dependent on their molecular transport properties, our fundamental understanding of these phenomena is far from complete. This is particularly true for the mechanisms that control the penetration rate through the outer surface of these materials (commonly referred to as surface barriers).

Interaction of molecular hydrogen with microporous metal organic framework materials at room temperature.

Infrared (IR) absorption spectroscopy measurements, performed at 300 K and high pressures (27-55 bar) on several prototypes of metal organic framework (MOF) materials, reveal that the MOF ligands are weakly perturbed upon incorporation of guest molecules and that the molecular hydrogen (H(2)) stretch mode is red-shifted (30-40 cm(-1)) from its unperturbed value (4155 cm(-1) for ortho H(2)). For MOFs of the form M(bdc)(ted)(0.5) (bdc = 1,4-benzenedicarboxylate; ted = triethylenediamine), H(2) molecules interact with the organic ligands instead of the saturated metal centers located at the corners of the unit cell.