Investigations of the Vicarious C‐Aminations of 5,7‐Dinitrobenzotriazole and 4,6‐Dinitrobenzotriazol‐3‐ium‐1‐oxide and Their Energetic Properties

This combined experimental and theoretical study details the vicarious nucleophilic substitution by amination of 5,7‐dinitrobenzotriazol ( 1 ) and 4,6‐dinitrobenzotriazole‐3‐ium‐1‐oxide ( 4 ) with trimethylhydrazinium iodide to afford the new corresponding one‐ and two‐time aminated compounds and investigations of its mechanism by EPR spectroscopy. The preferred position for the first amination is computed by spin density population and verified by X‐ray crystallography. The zwitterionic structure of 4 is investigated in solution by ¹H NMR spectroscopy and in solid state by X‐ray diffraction. Furthermore, the crystal structure of 1 is presented. The energetic behavior of the aminated products as well as the starting materials 1 and 4 was investigated, regarding sensitivities and performance.     

Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography

A collaborative study on the robustness and portability of a capillary electrophoresis‐mass spectrometry method for peptide mapping was performed by an international team, consisting of 13 independent laboratories from academia and industry. All participants used the same batch of samples, reagents and coated capillaries to run their assays, whereas they utilized the capillary electrophoresis‐mass spectrometry equipment available in their laboratories. The equipment used varied in model, type and instrument manufacturer. Furthermore, different types of sheath‐flow capillary electrophoresis–mass spectrometry interfaces were used. Migration time, peak height and peak area of ten representative target peptides of trypsin‐digested bovine serum albumin were determined by every laboratory on two consecutive days. The data were critically evaluated to identify outliers and final values for means, repeatability (precision within a laboratory) and reproducibility (precision between laboratories) were established. For relative migration time the repeatability was between 0.05 and 0.18% RSD and the reproducibility between 0.14 and 1.3% RSD. For relative peak area repeatability and reproducibility values obtained were 3–12 and 9–29% RSD, respectively. These results demonstrate that capillary electrophoresis‐mass spectrometry is robust enough to allow a method transfer across multiple laboratories and should promote a more widespread use of peptide mapping and other capillary electrophoresis‐mass spectrometry applications in biopharmaceutical analysis and related fields.     

Solid-State Photocyclodimerization of 1-Thiocoumarin (= 2H-1-Benzothiopyran-2-one)

Irradiation (λ > 390 nm) of 2H-1-benzothiopyran-2-one ( 1 ) in the solid state affords selectively 6aα,6bα,12bα,12cα -tetrahydrocyclobuta[1,2-c:4,3-c′]bis[1]benzothiopyran -6,7-dione ( 2 ), the head-to-head (HH) cis-cisoid-cis-dimer, while irradiation of 1 in the solid state using shorter wavelengths (λ > 340 nm) affords a mixture of all four cis-fused tricyclic dimers 2 – 5 . These results represent a novel wavelength effect in solid-state photochemistry.     

A Combined Spectroscopic and Theoretical Study on a Ruthenium Complex Featuring a π-Extended dppz Ligand for Light-Driven Accumulation of Multiple Reducing Equivalents

The design of photoactive systems capable of storing and relaying multiple electrons is highly demanded in the field of artificial photosynthesis, where transformations of interest rely on multielectronic redox processes. The photophysical properties of the ruthenium photosensitizer [(bpy)₂Ru( oxim-dppqp )]²⁺ ( Ru ), storing two electrons coupled to two protons on the π-extended oxim-dppqp ligand under light-driven conditions, are investigated by means of excitation wavelength-dependent resonance Raman and transient absorption spectroscopies, in combination with time-dependent density functional theory; the results are discussed in comparison to the parent [(bpy)₂Ru(dppz)]²⁺ and [(bpy)₂Ru( oxo-dppqp )]²⁺ complexes. In addition, this study provides in-depth insights on the impact of protonation or of accumulation of multiple reducing equivalents on the reactive excited states.     

Equiatomic Rare Earth (Ln) Transition Metal Antimonides LnTSb (T=Rh, lr) and Bismuthides LnTBi (T=Rh, Ni, Pd, Pt)

Thirty-eight new ternary equiatomic antimonides and bismuthides were prepared by reaction of the elemental components at high temperatures, and the structures of four compounds were refined from single-crystal X-ray data. The antimonides LnRhSb (Ln=Sm, Gd-Tm) and LnIrSb (Ln=La-Nd, Sm, Gd-Tm) crystallize with the orthorhombic TiNiSi-type structure, which was refined for TbRhSb (a=713.3(2) pm, b=452.0(1) pm, c=778.8(2) pm, R=0.016 for 306 structure factors and 20 variable parameters) and SmIrSb (a= 722.4(2) pm, b=452.9(1) pm, c=786.1(2) pm, R=0.023 for 559 F values and 20 variables). The bismuthides LnRhBi (Ln=Pr-Sm) also crystallize with TiNiSi-type structure which was refined for SmRhBi (a=728.0(2) pm, b=467.9(1) pm, c=795.7(2) pm, R=0.037 for 481 F values and 20 variables). The hexagonal ZrNiAl-type structure was established for the compounds LnRhBi (Ln=Gd-Er) through a structure refinement of DyRhBi (a=757.9(2) pm, c=392.6(1) pm, R=0.026 for 423 F values and 14 variables). The bismuthides LnNiBi (Ln=Pr, Nd, Sm, Tb, Ho, Er), ScPdBi, LnPdBi (Ln=La, Er, Tm, Lu), and LaPtBi are isotypic with cubic MgAgAs. The atomic order for these equiatomic ternary bismuthides was determined for PrNiBi and LaPtBi from X-ray powder data. The structural chemistry of these compounds is briefly discussed.