Linker Deprotonation and Structural Evolution on the Pathway to MOF-74.

The synthesis of MOF-74 (MOF = metal-organic framework) proceeds first through the generation of chemically and topologically distinct materials, referred to as phases, displaying exclusively carboxylate coordination, followed by further deprotonation to enable oxo coordination and MOF-74 formation. The synthesis of Mg-MOF-74 at high concentrations of linker and metal enables the stabilization and characterization of the previously unobserved, exclusively carboxylate coordinating phases. and approaches are leveraged to provide the time-resolved observation of Mg-MOF-74 synthesis and the formation of phases that precede Mg-MOF-74 formation as well as metastable phase dissolution.

Copper-Mediated Late-stage Radiofluorination: Five Years of Impact on Pre-clinical and Clinical PET Imaging.

Purpose: Copper-mediated radiofluorination (CMRF) is emerging as the method of choice for the formation of aromatic C-F bonds. This minireview examines proof-of-concept, pre-clinical, and in-human imaging studies of new and established imaging agents containing aromatic C-F bonds synthesized with CMRF. An exhaustive discussion of CMRF methods is not provided, although key developments that have enabled or improved upon the syntheses of fluorine-18 imaging agents are discussed.

Classics in Neuroimaging: Shedding Light on Opioid Receptors with Positron Emission Tomography Imaging.

Imaging of the opioid system was one of the earliest applications of Positron Emission Tomography (PET) imaging in neuroscience that remains in widespread use today and in the age of the opioid crisis the technique is as important as ever. In this viewpoint the rich history of opioid imaging using PET is highlighted, including discussion of the preferred radiotracers for imaging of μ, δ, κ and ORL-1 receptors in clinical applications. We also draw attention to key innovations that were essential to development of radiotracers for imaging opioid receptors including production of high molar activity PET radionuclides and new approaches to radiochemistry.