Extending tetrahedral network similarity to carbon: A type-I carbon clathrate stabilized by boron.

Clathrates are guest/host framework compounds composed of polyhedral cages, yet despite their prevalence among tetrahedral network formers, clathrates with a carbon host lattice remain unrealized synthetic targets. Here, we report a type-I carbon-based framework-a ubiquitous clathrate structure type found throughout compounds containing tetrahedral building blocks. Following a boron-stabilization scheme based on first-principles predictions in the Ca-B-C system at high pressure, type-I CaBC ( ≈ 9) was synthesized in the archetypal [Formula: see text] lattice with stability derived from substitutionally disordered boron atoms on hexagonal ring framework positions.

A Sodium Germanosilicide with Unusual Network Topology.

The germanosilicide NaGeSi (0.4 ≤ ≤ 1.1, 4.

Arsenic(III) oxide intercalate with ammonium chloride: crystal structure revision and thermal characterization.

According to the crystal structure determination by Edstrand & Blomqvist [Ark. Kemi (1955), 8, 245-256], intercalate NHCl·AsO·0.5HO ({\bf Y_{{NH}_{4}Cl}}) is not isostructural with compound KCl·AsO·0.

Influence of substituents in aryl groups on the structure, thermal transitions and electrorheological properties of zinc bis(diarylphosphate) hybrid polymers.

The structures and thermal properties of three new hybrid one-dimensional (1D) polymers based on zinc bis(diarylphosphate)s containing -substituted phenyl rings are reported. The crystal structures of Zn[OP(-OCHNO)] (1), Zn[OP(-OCHOMe)] (2) and Zn[OP(-OCHCOEt)] (3) differ from that of their unsubstituted analogue, Zn[OP(OPh)] (ZnDPhP). Compounds 1 and 3 consist of tetrahedrally coordinated zinc cations connected by double bridges of phosphate groups (2+2 bridging mode) and form polymeric chains that are packed in a distorted hexagonal lattice with six closest neighbours.

Fast, solvent-free synthesis of ferrocene-containing organic cages dynamic covalent chemistry in the solid state.

A simple, solvent-free synthetic protocol towards the synthesis of organic self-assembled macromolecules has been established. By employing mechanochemistry using glassware readily available to every organic chemist, we were able to synthesise three novel organic cage compounds exemplarily and to speed up the synthesis of a ferrocene-containing macrocycle by a factor of 288 compared to the solution-based synthesis. The structural investigation of the newly synthesised cages revealed different modes of connectivity from using ferrocene-containing aldehydes caused by the free rotation of the cyclopentadienyl units against each other.

1D and 2D hybrid polymers based on zinc phenylphosphates: synthesis, characterization and applications in electroactive materials.

The synthesis, structure and properties of three hybrid polymers based on zinc arylphosphates are described in this study. Zinc bis(diphenylphosphate) (ZnDPhP) was obtained as needle-like crystals containing hexagonally packed, homochiral [Zn(DPhP)] helical chains. The XRD and DSC studies revealed that upon heating, ZnDPhP undergoes a reversible thermal transition at 160 °C with expansion mainly perpendicular to its -axis.

Crystal Structure and Non-Hydrostatic Stress-Induced Phase Transition of Urotropine Under High Pressure.

High-pressure behavior of hexamethylenetetramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier-transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure-transmitting media to study the effect of deviatoric stress on phase transformations. Up to 4 GPa significant damping of molecular librations and atomic thermal motion was observed.

Synthesis and structural, electrochemical and photophysical studies of triferrocenyl-substituted 1,3,5-triphenylbenzene: a cyan-light emitting molecule showing aggregation-induced enhanced emission.

Triferrocenyl-substituted 1,3,5-triphenylbenzene was successfully synthesized in high yield. Single-crystal X-ray diffraction experiments revealed that the internal rotations of the ferrocenyl moieties are significantly restricted in the solid phase and that there are no significant π stacking interactions therein. The photoluminescence of the crystals is essentially the same as that of dilute chloroform solutions.

Raman studies of hydrogen trapped in AsO·2H at high pressure and low temperature.

Raman spectroscopic measurements of the arsenolite-hydrogen inclusion compound AsO·2H were performed in diamond anvil cells at high pressure and variable temperature down to 80 K. The experimental results were complemented by ab initio molecular dynamics simulations and phonon calculations. Observation of three hydrogen vibrons in AsO·2H is reported in the entire temperature and pressure range studied (up to 24 GPa).

A ferrocene-templated Pd-bearing molecular reactor.

High-yield, chromatography-free syntheses of a ferrocene-templated molecular cage and its Pd-bearing derivative are presented. The formation of a symmetric cage-type structure was confirmed by single-crystal X-ray diffraction analysis. The Pd-bearing cage was used as an innovative catalyst for the efficient synthesis of 1,1'-biphenyls under mild conditions.

Effect of the substituent position on the electrochemical, optical and structural properties of donor-acceptor type acridone derivatives.

Three new donor-acceptor (D-A) compounds, positional isomers of phenoxazine-substituted acridone, namely 1-phenoxazine-N-hexylacridone (o-A), 2-phenoxazine-N-hexylacridone (m-A) and 3-phenoxazine-N-hexylacridone (p-A), were synthesized. The synthesized compounds showed interesting, isomerism-dependent electrochemistry. Their oxidation was reversible and their potential (given vs.

Carbon-boron clathrates as a new class of sp-bonded framework materials.

Carbon-based frameworks composed of sp bonding represent a class of extremely lightweight strong materials, but only diamond and a handful of other compounds exist despite numerous predictions. Thus, there remains a large gap between the number of plausible structures predicted and those synthesized. We used a chemical design principle based on boron substitution to predict and synthesize a three-dimensional carbon-boron framework in a host/guest clathrate structure.

Integrating Activity with Accessibility in Olefin Metathesis: An Unprecedentedly Reactive Ruthenium-Indenylidene Catalyst.

Access to leading olefin metathesis catalysts, including the Grubbs, Hoveyda, and Grela catalysts, ultimately rests on the nonscaleable transfer of a benzylidene ligand from an unstable, impure aryldiazomethane. The indenylidene ligand can be reliably installed, but to date yields much less reactive catalysts. A fast-initiating, dimeric indenylidene complex () is reported, which reconciles high activity with scaleable synthesis.

Towards a quantitative bond valence description of coordination spheres - the concepts of valence entropy and valence diversity coordination numbers.

Two novel definitions of chemical coordination numbers - valence entropy coordination number VECN and valence diversity coordination number VDCN - are proposed. Their originality stems from the fact that they are the first definitions based solely on bond valences. The expressions for them are derived from their definitions and their properties are studied.

How and Why Does Helium Permeate Nonporous Arsenolite Under High Pressure?

Investigations into the helium permeation of arsenolite, the cubic, molecular arsenic(III) oxide polymorph As O , were carried out to understand how and why arsenolite helium clathrate As O ⋅2 He is formed. High-pressure synchrotron X-ray diffraction experiments on arsenolite single crystals revealed that the permeation of helium into nonporous arsenolite depends on the time for which the crystal is subjected to high pressure and on the crystal history. The single crystal was totally transformed into As O ⋅2 He within 45 h under 5 GPa.

Bis(Cyclic Alkyl Amino Carbene) Ruthenium Complexes: A Versatile, Highly Efficient Tool for Olefin Metathesis.

The state-of-the-art in olefin metathesis is application of N-heterocyclic carbene (NHC)-containing ruthenium alkylidenes for the formation of internal C=C bonds and of cyclic alkyl amino carbene (CAAC)-containing ruthenium benzylidenes in the production of terminal olefins. A straightforward synthesis of bis(CAAC)Ru indenylidene complexes, which are highly effective in the formation of both terminal and internal C=C bonds at loadings as low as 1 ppm, is now reported.

Soluble Flavanthrone Derivatives: Synthesis, Characterization, and Application to Organic Light-Emitting Diodes.

Simple modification of benzo[h]benz[5,6]acridino[2,1,9,8-klmna]acridine-8,16-dione, an old and almost-forgotten vat dye, by reduction of its carbonyl groups and subsequent O-alkylation, yields solution-processable, electroactive, conjugated compounds of the periazaacene type, suitable for the use in organic electronics. Their electrochemically determined ionization potential and electron affinity of about 5.2 and -3.

Spatial dispersion of lone electron pairs?--experimental charge density of cubic arsenic(III) oxide.

The first experimental charge density study of arsenolite, a cubic polymorph of arsenic(III) oxide, extended by periodic DFT calculations is reported. The presence of weak AsO interactions is confirmed and their topological characterization based on experimental electron density is provided. Spatial dispersion of arsenic lone electron pairs into three domains is observed in the Laplacian of electron density as well as in the electron localization function.

Indanthrone dye revisited after sixty years.

Indanthrone, an old, insoluble dye can be converted into a solution processable, self-assembling and electroluminescent organic semiconductor, namely tetraoctyloxydinaptho[2,3-a:2',3'-h]phenazine (P-C8), in a simple one-pot process consisting of the reduction of the carbonyl group by sodium dithionite followed by the substitution with solubility inducing groups under phase transfer catalysis conditions.

The structure and energetics of arsenic(III) oxide intercalated by ionic azides.

Unprecedented intercalates of arsenic(iii) oxide with potassium azide and ammonium azide have been obtained and characterized by single crystal X-ray diffraction. The compounds are built of As2O3 sheets separated by charged layers of cations and azide anions perpendicular to the sheets. The intercalates are an interesting example of hybrid materials whose structure is governed by covalent bonds in two directions and ionic bond in the third one.

Anion exchange in [Ni(η(5)-C(5)H(4)R)(Cl)(NHC)]. Counterion effect on the structure and catalytic activity.

A series of novel complexes [Ni(η(5)-C5H4R)(L)(NHC)](+)A(-)2a-2j and [Ni(η(5)-C5H5)(A)(NHC)] 3a-3c has been obtained by anion metathesis from the corresponding chlorides 1a-1d, depending on the anion binding properties and reaction conditions. Solid-state structures of two cationic complexes (2c, 2j) and two complexes with a coordinated anion (3a, 3c) have been determined by X-ray diffraction revealing a trigonal planar geometry in all cases. Unexpectedly, 3c displayed unprecedented for this type of compounds temperature-dependent NMR spectra that were interpreted in terms of spin equilibrium.