Indium α radiation from a MetalJet X-ray source: the long way to a successful charge-density investigation.

The MetalJet X-ray source provides indium α radiation with a wavelength even shorter than Ag radiation. This paper reports on problematic spectral impurities and presents possible countermeasures so that collection of data with excellent quality up to a high resolution is possible. It is demonstrated that these data can be used in the refinement of a multipole model, the results of which are used for a topological analysis to assess the bonding situation in a sulfur ylide compound.

Indium α radiation from a MetalJet X-ray source: comparison of the Eiger2 CdTe and Photon III detectors.

The MetalJet source makes available new α radiation wavelengths for use in X-ray diffraction experiments. The purpose of this paper is to demonstrate the application of indium α radiation in independent-atom model refinement, as well as approaches using aspherical atomic form factors. The results vary greatly depending on the detector employed, as the energy cut-off of the Eiger2 CdTe provides a solution to a unique energy contamination problem of the MetalJet In radiation, which the Photon III detector cannot provide.

A donor-supported silavinylidene and silylium ylides: boroles as a flexible platform for versatile Si(ii) chemistry.

Electron-deficient, -aromatic 2,5-disilyl boroles are shown to be a flexibly adaptive molecular platform with regards to SiMe mobility in their reaction with the nucleophilic donor-stabilised precursor dichloro silylene SiCl(IDipp). Depending on the substitution pattern, selective formation of two fundamentally different products of rivalling formation pathways is achieved. Formal addition of the dichlorosilylene gives the 5,5-dichloro-5-sila-6-borabicyclo[2.

One silicon atom of bis(silylene) functions as a selective Lewis base under adduct formation with a Lewis acid.

Herein, we describe the facile and selective one-pot synthetic route to silylene-aluminum and silylene-gallium adducts. Reduction of silylene LSiCl (L = PhC(NBu)) with KC in the presence of bulky and sterically hindered cyclopentadienyl aluminum Cp'''AlCl (Cp''' = 1,2,4-BuCH) and gallium [η-Cp'''Ga(μ-Cl)Cl] to afford the Lewis acid-base adducts η-Cp'''M(Cl) ← Si(L)-SiL (M = Al, 1; M = Ga, 3). To confirm the formation of the Lewis acid-base adduct, the bis(silylene) LSi(I)-Si(I)L reacts with Cp'''AlI to form η-Cp'''Al(I) ← Si(L)-SiL (2).

Linear and Bent Cp* Si: Reversible Phase Transition of a Key Molecule.

The solid-state structure of decamethylsilicocene Cp* Si with a bent and a linear molecule in the same unit cell was so far considered an exception in relation to the structures of its all-bent heavier analogues Cp* E with E=Ge, Sn, Pb. Here, we present the solution to this conundrum by reporting a low-temperature phase, where all three symmetrically independent molecules are present in a bent formation. This reversible enantiotropic phase transition occurs in the temperature range between 80 K and 130 K and provides a rationale for the unexpected linear molecule based in entropy beyond hand-waving explanations such as electronic reasons or packing effects.

Insertion Reaction of MeSiN with Bis(germylene).

Herein, we describe the redox reaction of bis(germylene) PhC(NBu)Ge-Ge(NBu)CPh with different equivalents of MeSiN affording two distinct products. The reaction of MeSiN with bis-germylene in a 1:1 molar ratio results in compound at -78 °C; however, treatment of bis-germylene with a 2.1 equiv of MeSiN at room temperature results in compound .

Trapping X-ray Radiation Damage from Homolytic Se-C Bond Cleavage in BnSeSeBn Crystals (Bn=benzyl, CH C H ).

Irradiation of dibenzyl diselenide BnSeSeBn with X-ray or UV-light cleaves the Se-C and the Se-Se bonds, inducing stable and metastable radical states. They are inevitably important to all natural and life sciences. Structural changes due to X-ray-induced Se-C bond-cleavage could be pin-pointed in various high-resolution X-ray diffraction experiments for the first time.

Hirshfeld atom refinement based on projector augmented wave densities with periodic boundary conditions.

Hirshfeld atom refinement (HAR) is an X-ray diffraction refinement method that, in numerous publications, has been shown to give H-atom bond lengths in close agreement with neutron diffraction derived values. Presented here is a first evaluation of an approach using densities derived from projector augmented wave (PAW) densities with three-dimensional periodic boundary conditions for HAR. The results show an improvement over refinements that neglect the crystal environment or treat it classically, while being on a par with non-periodic approximations for treating the solid-state environment quantum mechanically.

Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal.

Herein, we report the stabilization of nitrene reagents as the source of a nitrogen atom to synthesize nitrogen-incorporated R LSi-N←SiLR (1) [L=PhC(NtBu) ; R =NTMS , R =NTMS]. Compound 1 is synthesized by reacting LSi(I)-Si L with 3.1 equivalents of Me SiN at low temperature to afford a triene-like structural framework.

Pentamethyl- and 1,2,4-tri(tert-butyl)cyclopentadienyl containing p-block complexes - differences and similarities.

The sterically encumbered cyclopentadienyl ligand 1,2,4-(MeC)CH (Cp''') was used to stabilize efficiently the main group metals of Al, Ga, In, Ge and Sn, respectively. The σ-bonded gallium compounds [η-Cp'''Ga(μ-X)X] (X = Cl, 2; X = I, 3) and indium compound [η-Cp'''In(μ-Br)Bu] (7) exhibit dimers through halogen bridges. Reduction of 2 with 2 equivalents of KC leads almost to the same amount of η-Cp'''Ga(THF)Cl (4) and η-Cp'''Ga (5), respectively.

Analysis of Solid-State Luminescence Emission Amplification at Substituted Anthracenes by Host-Guest Complex Formation.

Invited for the cover of this issue are Dietmar Stalke and coworkers from the Georg-August Universität at Göttingen. The image symbolizes the organization of small arenes in the pocket of thiophosphoranyl substituted anthracene like the construction of a stable wall from a loose pile of bricks, shifting the emission to the green and amplifying it by a factor of five. Read the full text of the article at 10.

Analysis of Solid-State Luminescence Emission Amplification at Substituted Anthracenes by Host-Guest Complex Formation.

Small robust organic molecules showing solid-state luminescence are promising candidates for optoelectronic materials. Herein, we investigate a series of diphenylphosphanyl anthracenes [9-PPh -10-R-(C H )] and their sulfur oxidised analogues. The oxidation causes drastic changes in the molecular structure as the new orientation of the bulky (S)PPh substituent induces a strong butterfly bent structure of the anthracene core, which triggers a strong bathochromic shift resulting in a green solid-state fluorescence.

Three colour solid-state luminescence from positional isomers of facilely modified thiophosphoranyl anthracenes.

Three positional isomers of thiophosphoranyl anthracene were synthesized and their photophysical properties were investigated. By varying the position of the substituents, blue, green and yellow solid-state fluorescence with differences in the emission wavelength of over 100 nm, assigned to the intra- and intermolecular effects, could be established.

A Neutral "Aluminocene" Sandwich Complex: η - versus η -Coordination Modes of a Pentaarylborole with ECp* (E=Al, Ga; Cp*=C Me ).

The pentaaryl borole (Ph*C) BXyl [Ph*=3,5-tBu (C H ); Xyl =3,5-(CF ) (C H )] reacts with low-valent Group 13 precursors AlCp* and GaCp* by two divergent routes. In the case of [AlCp*] , the borole reacts as an oxidising agent and accepts two electrons. Structural, spectroscopic, and computational analysis of the resulting unprecedented neutral η -Cp*,η -[(Ph*C) BXyl ] complex of Al revealed a strong, ionic bonding interaction.

Isolation of Transient Acyclic Germanium(I) Radicals Stabilized by Cyclic Alkyl(amino) Carbenes.

Despite the notable progress in the stabilization of main group radicals by NHCs and cAACs, no germanium radicals have been isolated so far due to synthetic challenges. Stabilization of neutral [:ER] (E = Si, Ge) radicals is an uphill task, as these reactive transient species are highly susceptible to dimerization. Herein, we report the synthesis of acyclic neutral germanium(I) radicals Cy-cAAC:GeN(SiMe)Dip (1) and Me-cAAC:GeN(SiPh)Mes (2) obtained by the reduction of [Ar(SiR)NGeCl] with KC in the presence of cAAC.

Synthesis and Ring Strain of a Benzoborirene-N-Heterocyclic Carbene Adduct.

The reduction of an N-heterocyclic carbene (1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene, IiPr ) adduct of dichloro(ortho-bromophenyl)borane by tert-butyl lithium at low temperature yields the IiPr adduct A of parent benzoborirene, a highly strained boron-containing bicyclic compound. A is unstable at room temperature and dimerizes at low temperature to the bis-IiPr adduct of 9,10-dihydro-9,10-diboraanthracene, characterized by single-crystal X-ray crystallography.

Silanylidene and Germanylidene Anions: Valence-Isoelectronic Species to the Well-Studied Phosphinidene.

The reduction of TipMCl (Tip=2,4,6-triisopropylphenyl) (M=Si, Ge) with KC in the presence of cyclic alkyl(amino) carbene (cAAC) afforded the acyclic silanylidene and germanylidene anions in the form of potassium salt [K(cAAC)MTip] (M=Si (1); Ge (2)). The silanylidene and germanylidene anions are valence-isoelectronic to the well-studied phosphinidene and are a new class of acyclic anions of Group 14. Compounds 1 and 2 were isolated and well characterized by NMR and single-crystal X-ray structure analysis.

Ruthenium(II)-Catalyzed meta C-H Mono- and Difluoromethylations by Phosphine/Carboxylate Cooperation.

Ruthenium(II)-catalyzed meta-selective C-H (di)fluoromethylation was accomplished by phosphine and carboxylate cooperation. The remote C-H functionalization was characterized by ample substrate scope, thereby setting the stage for meta-(di)fluoromethylation through facile C-H cleavage.