Reply to the ‘Comment on “Uncommon structural and bonding properties in Ag16B4O10” by A. Lobato,Miguel Á. Salvadó, and J. Manuel Recio,Chem. Sci., 2021, 12, DOI: 10.1039/D1SC02152D

Where are the excess electrons in Ag₁₆B₄O₁₀?

Ag₁₆B₄O₁₀ features an exotic scheme of chemical bonding and extends the growing family of subvalent silver oxides. These findings constitute a new general and intrinsic facet of the chemistry of silver, which has not been fully understood, yet, and definitely deserves to be analysed from different perspectives. Against this background, we distinctly appreciate the efforts made by A. Lobato, Miguel Á. Salvadó, and J. Manuel Recio (LSR) in studying these phenomena at the example of the title compound.¹ While the computational results presented in the Comment article well comply with those published in our original paper,² the interpretations follow different routes. Whereas LSR focus on the analogy of pattern of the Electron Localization Function (ELF) in position space in the title compound with those found in elemental silver, we interpreted the electronic structure of Ag₁₆B₄O₁₀, both in position and reciprocal space, also considering the interactions between cationic and anionic partial structures.     

Zwei Tetrachlorothiotantalate: [Na‐15‐Krone‐5][TaSCl4 · Dioxan] und [Na‐15‐Krone‐5]2[(TaSCl4)2Dioxan] · S8

Two Tetrachlorothiotantalates: [Na‐15‐crown‐5][TaSCl₄ · dioxane] and [Na‐15‐crown‐5]₂[(TaSCl₄)₂dioxane] · S₈ During the reaction of Na₂S₄, TaCl₅ and 15‐crown‐5 in dichloromethane the crown ether partly suffers degradation to 1,4‐dioxane. Aside from sulfur, [Na‐15‐crown‐5][TaSCl₄ · dioxane] was the first product obtained. It crystallizes in the monoclinic space group P2₁/n with a = 1066.1, b = 1781.3, c = 1258.3 pm, β = 97.14°, Z = 4. In the [TaSCl₄ · dioxane]^– ion a dioxane molecule is loosely bonded to a square‐pyramidal TaSCl₄^– unit; two chlorine atoms are in contact with an Na⁺ ion. Upon standing with the mother liquor [Na‐15‐crown‐5]₂[(TaSCl₄)₂dioxane] · S₈ was formed. It crystallizes in the monoclinic space group C2/m; a = 1768.5, b = 1084.0, c = 1517.3 pm, β = 118.46°, Z = 4. In this case a dioxane molecule is coordinated with two TaSCl₄^– units. The [(TaSCl₄)₂ · dioxane]^2– ions and S₈ molecules alternate in the stacking direction b.     

Calcium,Strontium, and Barium Acetylides—New Evidence for Bending in the Structures of Heavy Alkaline Earth Metal Derivatives

An unprecedented ligand bending mode is displayed by the acetylide ligands in the first structurally characterized σ‐bound organometallic strontium and barium complexes [M([18]crown‐6)(CCSiPh₃)₂] (M=Sr, Ba). Furthermore, the observed decrease of the angle at the sp‐hybridized C atom on descending Group 2 (see structures depicted) affords new information that will lead to a better understanding of the bonding in alkaline earth metal compounds.     

Formation of Novel Dinuclear Mixed-Valence Rhodium Complexes by Intramolecular Migration of a Chelating Ligand

Significantly different coordination spheres are displayed by the two central atoms of 2 , the first representative of a novel type of mixed-valence dinuclear Rh⁰–Rh^II compound, which was synthesized from the stibane-bridged complex 1 . The Rh−Rh distance determined by an X-ray crystal structure analysis of 2 indicates a metal–metal interaction between the two metal centers.     

Identification of Triplet States in Carotenoids by Intracavity Absorption Spectroscopy and Measurements of Delayed Fluorescence

Owing to the low quantum yield of phosphorescence , triplet states of carotenoids have been very difficult to identify. These states can be characterized by intracavity absorption spectroscopy, which allows the direct measurement of the spin-forbidden singlet–triplet transitions in low concentrated solutions, and by delayed fluorescence measurements.     

On-Line Coupling of Separation Techniques to NMR

The hyphenation of chromatographic separation techniques with NMR spectroscopy is one of the most powerful and time-saving methods for the separation and structural elucidation of unknown compounds and molecular compositions of mixtures. Most of the routinely used NMR flow-cells have detection volumes between 40–180 μL for conventional separations with analytical columns, and the newest designs employ detection volumes in the order of 200 nL for capillary separations. The low flow rates used in capillary chromatography permit the use of deuterated solvents. Unequivocal structural assignment of unknown chromatographic peaks is possible by two-dimensional stopped-flow capillary HPLC-NMR experiments.