Instruments. NMR spectra were obtained with Bruker AC-300 and Varian UNITY-500 spectrometers. Mass spectra were obtained with Perkin Elmer Sciex API 365 electrospray ionization (ESI) and Bruker Biflex III matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) instruments at the University of Wisconsin Biotechnology Center. Ultraviolet and visible absorbance was recorded with a Cary Model 3 UV/VIS spectrophotometer from Varian equipped with a Varian temperature controller.

Selenocysteine in Native Chemical Ligation and Expressed Protein Ligation

Metal-organic frameworks (MOFs), constructed from organic linkers and inorganic building blocks, are well-known for their high crystallinity, high surface areas, and high component tunability. The stability of MOFs is a key prerequisite for their potential practical applications in areas including storage, separation, catalysis, and biomedicine since it is essential to guarantee the framework integrity during utilization. However, MOFs are prone to destruction under external stimuli, considerably hampering their commercialization. In this Review, we provide an overview of the situations where MOFs undergo destruction due to external stimuli such as chemical, thermal, photolytic, radiolytic, electronic, and mechanical factors and offer guidelines to avoid unwanted degradation happened to the framework. Furthermore, we discuss possible destruction mechanisms and their varying derived products. In particular, we highlight cases that utilize MOF instability to fabricate varying materials including hierarchically porous MOFs, monolayer MOF nanosheets, amorphous MOF liquids and glasses, polymers, metal nanoparticles, metal carbide nanoparticles, and carbon materials. Finally, we provide a perspective on the utilization of MOF destruction to develop advanced materials with a superior hierarchy for various applications.

Destruction of Metal-Organic Frameworks: Positive and Negative Aspects of Stability and Lability.

A compendium of phase change enthalpies published in 2010 is updated to include the period 1880–2015. Phase change enthalpies including fusion, vaporization, and sublimation enthalpies are included for organic, organometallic, and a few inorganic compounds. Part 1 of this compendium includes organic compounds from C1 to C10. Part 2 of this compendium, to be published separately, will include organic and organometallic compounds from C11 to C192. Sufficient data are presently available to permit thermodynamic cycles to be constructed as an independent means of evaluating the reliability of the data. Temperature adjustments of phase change enthalpies from the temperature of measurement to the standard reference temperature, T = 298.15 K, and a protocol for doing so are briefly discussed.

Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2015. Part 1. C1-C10

Thermal stability and heat capacity of several metal–organic frameworks and their corresponding organic ligands have been investigated systematically using TGA-DSC technique. A simple notation system was created to present the local coordination environment around metal atoms in a secondary building unit (SBU). The heat capacity contributions of organic functional groups and SBUs were examined using the group-contribution method. Our results suggest that the thermal stability of MOFs is determined by the coordination number and local coordination environment instead of framework topology. Specific heat capacities (Cp) of all examined MOFs exhibit comparable values as other solids including carbon nanotubes, zeolites, and minerals. The molar heat capacity contributions of SBUs in MOFs indicate similar abnormal thermal behavior as negative thermal expansion of MOFs.

W. T. Lewis

Papers

Latent heat of sublimation of terephthalic acid from differential thermal analysis data