Supramolecular chemistry in solution and solid-gas interfaces: synthesis and photophysical properties of monocolor and bicolor fluorescent sensors for barium tagging in neutrinoless double beta decay.

Translation of photophysical properties of fluorescent sensors from solution to solid-gas environments functionalized surfaces constitutes a challenge in chemistry. In this work, we report on the chemical synthesis, barium capture ability and photophysical properties of two families of monocolor and bicolor fluorescent sensors. These sensors were prepared to capture barium cations that can be produced in neutrinoless double beta decay of Xe-136.

Density Functional Theory Study on the Demethylation Reaction between Methylamine, Dimethylamine, Trimethylamine, and Tamoxifen Catalyzed by a Fe(IV)-Oxo Porphyrin Complex.

In this work, we studied computationally the N-demethylation reaction of methylamine, dimethylamine, and trimethylamine as archetypal examples of primary, secondary, and tertiary amines catalyzed by high-field low-spin Fe-containing enzymes such as cytochromes P450. Using DFT calculations, we found that the expected C-H hydroxylation process was achieved for trimethylamine. When dimethylamine and methylamine were studied, two different reaction mechanisms (C-H hydroxylation and a double hydrogen atom transfer) were computed to be energetically accessible and both are equally preferred.

Two-State Reactivity of Histone Demethylases Containing Jumonji-C Active Sites: Different Mechanisms for Different Methylation Degrees.

The N-demethylation reactions of N,N,N-trimethylpropan-1-ammonium and N,N-dimethyl- and N-methylpropan-1-aminium cations in the presence of [(AcO) (imidazole) (H O)Fe=O] complex have been studied by density functional theory. These transformations are suitable models for the N-demethylation of tri-, di-, and monomethylated lysine residues of histones in the presence of Jumonji-C containing histone demethylases. It has been found that the N-demethylation reaction is stepwise and occurs on triplet and quintet potential energy hypersurfaces.