Enhanced Gas Adsorption on Cu(BTC) Metal-Organic Framework by Post-Synthetic Cation Exchange and Computational Analysis.

Increased gas adsorption in a series of post-synthetically modified metal-organic frameworks (MOFs) of the type HKUST-1 was achieved by the partial cation exchange process. Manipulation of post-synthetic conditions demonstrates high tunability in the site substitution and gas adsorption properties during the dynamic equilibrium process. In this work, post-synthetic modification of Cu(BTC) is carried on by exposure to TM solutions (TM = Mn, Fe, Co, Ni) at different time intervals.

Trioxatriangulenium (TOTA) as a robust carbon-based Lewis acid in frustrated Lewis pair chemistry.

We report the reactivity between the water stable Lewis acidic trioxatriangulenium ion (TOTA) and a series of Lewis bases such as phosphines and N-heterocyclic carbene (NHC). The nature of the Lewis acid-base interaction was analyzed variable temperature (VT) NMR spectroscopy, single-crystal X-ray diffraction, UV-visible spectroscopy, and DFT calculations. While small and strongly nucleophilic phosphines, such as PMe, led to the formation of a Lewis acid-base adduct, frustrated Lewis pairs (FLPs) were observed for sterically hindered bases such as P( Bu).

Persistent, highly localized, and tunable [4]helicene radicals.

Persistent organic radicals have gained considerable attention in the fields of catalysis and materials science. In particular, helical molecules are of great interest for the development and application of novel organic radicals in optoelectronic and spintronic materials. Here we report the syntheses of easily tunable and stable neutral quinolinoacridine radicals under anaerobic conditions by chemical reduction of their quinolinoacridinium cation analogs.

Helical Carbenium Ion: A Versatile Organic Photoredox Catalyst for Red-Light-Mediated Reactions.

Red light has the advantages of low energy, less health risks, and high penetration depth through various media. Herein, a helical carbenium ion (-di--propyl-1,13-dimethoxyquinacridinium (Pr-DMQA) tetrafluoroborate) has been used as an organic photoredox catalyst for photoreductions and photooxidations in the presence of red light (λ = 640 nm). It has catalyzed red-light-mediated dual transition-metal/photo-redox-catalyzed C-H arylation and intermolecular atom-transfer radical addition through oxidative quenching.

Tunable carbocation-based redox active ambiphilic ligands: synthesis, coordination and characterization.

The synthesis of novel redox active ambiphilic ligands L1-L3 and their coordination chemistry to first-row late transition metal halides (M = Co and Ni) is reported. The heterocyclic carbocation scaffolds act as Lewis acid moieties while the pyridine anchor acts as the coordinating Lewis base. The high synthetic tunability of this ligand scaffold allows for control of its rigidity and electronic properties.

Efficient electrocatalytic hydrogen gas evolution by a cobalt-porphyrin-based crystalline polymer.

Herein, we report a crystalline CoTcPP-based [TcPP = the anion of meso-tetra(4-carboxyphenyl)porphyrin] polymeric system, 1, as a hydrogen evolution reaction (HER) electrocatalyst in acidic aqueous media. The material was characterized by powder X-ray diffraction (p-XRD), Fourier transform infrared (FT-IR) spectroscopy, and energy dispersive X-ray (EDX) analysis and its morphology was probed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Polymer 1 shows a surface area of 441.

[U(bipy) ]: A Mistaken Case of U ?

After more than 50 years, the synthesis and electronic structure of the first and only reported "U complex" [U(bipy) ] (1) has been reinvestigated. Additionally, its one-electron reduced product [Na(THF) ][U(bipy) ] (2) has been newly discovered. High resolution crystallographic analyses combined with magnetic and computational data show that 1 and its derivative 2 are best described as highly reduced species containing mid-to-high-valent uranium ligated by redox non-innocent ligands.