Dibenzyl isophthalates as versatile hosts in room temperature phosphorescence host-guest systems.

We report a series of dibenzyl isophthalates (DBIs) as novel hosts for room-temperature phosphorescence (RTP) host-guest systems, achieving RTP quantum yields (QY) of up to 77% or lifetimes of up to 21.0 s with the guest coronene- . Furthermore, a 4,4'-Br substituted DBI was used to form host-guest RTP systems with 15 different aromatic guest molecules, to tune the phosphorescence emission color from blue to red and to demonstrate the versatility of the host.

Experimental and Theoretical Force Constants as Meaningful Indicator for Interatomic Bonding Characteristics and the Specific Case of Elemental Antimony.

Stable Sb exhibits a rhombohedral structure, often referred to as distorted primitive cubic, with each Sb atom having three short and three longer first neighbor bonds. However, this crystal structure can also be interpreted as being layered, putting emphasis on only three short first neighbor bonds. Therefore, temperature-dependent extended X-ray absorption fine structure (EXAFS) spectroscopy is carried out at the Sb K-edge in order to obtain more detailed information on local structural and vibrational properties.

Synthesis, structural and spectroscopic characterization of defect-rich forsterite as a representative phase of Martian regolith.

Regolith draws intensive research attention because of its importance as the basis for fabricating materials for future human space exploration. Martian regolith is predicted to consist of defect-rich crystal structures due to long-term space weathering. The present report focuses on the structural differences between defect-rich and defect-poor forsterite (MgSiO) - one of the major phases in Martian regolith.

Determination of the average crystallite size and the crystallite size distribution: the envelope function approach EnvACS.

A procedure is presented to exactly obtain the apparent average crystallite size (ACS) of powder samples using standard in-house powder diffraction experiments without any restriction originating from the Scherrer equation. Additionally, the crystallite size distribution within the sample can be evaluated. To achieve this, powder diffractograms are background corrected and long-range radial distribution functions () up to 300 nm are calculated from the diffraction data.

Unravelling White Phosphorus: Experimental and Computational Studies Reveal the Mechanisms of P Hydrostannylation.

The hydrostannylation of white phosphorus (P) allows this crucial industrial precursor to be easily transformed into useful P products via direct, 'one pot' (or even catalytic) procedures. However, a thorough mechanistic understanding of this transformation has remained elusive, hindering attempts to use this rare example of successful, direct P functionalization as a model for further reaction development. Here, we provide a deep and generalizable mechanistic picture for P hydrostannylation by combining DFT calculations with in situ P NMR reaction monitoring and kinetic trapping of previously unobservable reaction intermediates using bulky tin hydrides.

Synthesis of a stable crystalline nitrene.

Nitrenes are a highly reactive, yet fundamental, compound class. They possess a monovalent nitrogen atom and usually a short life span, typically in the nanosecond range. Here, we report on the synthesis of a stable nitrene by photolysis of the arylazide MFluindN (), which gave rise to the quantitative formation of the arylnitrene MFluindN () (MFluind is dispiro[fluorene-9,3'-(1',1',7',7'-tetramethyl-s-hydrindacen-4'-yl)-5',9''-fluorene]) that remains unchanged for at least 3 days when stored under argon atmosphere at room temperature.

Thermal behaviors during lithium diffusion in LiWO bronze studied by elastic and quasi-elastic neutron scattering.

Polycrystalline LiWO bronze has been synthesized by solid state reaction carried out in a silica tube at 10 MPa and 973 K. The sample is characterized by temperature-dependent neutron elastic and quasielastic scatterings. The room-temperature neutron powder data Rietveld refinement confirmed the space group 3̄ along with lithium occupancy found predominantly at the 6 crystallographic site.

CrSiPN-A Chromium(+IV) Nitridosilicate Phosphate with Amphibole-Type Structure.

The first nitridic analog of an amphibole mineral, the quaternary nitridosilicate phosphate CrSiPN was synthesized under high-pressure high-temperature conditions at 1400 °C and 12 GPa from the binary nitrides CrN, SiN and PN, using NHN and NHF as additional nitrogen source and mineralizing agent, respectively. The crystal structure was elucidated by single-crystal X-ray diffraction with microfocused synchrotron radiation (C2/m, a=9.6002(19), b=17.

High-Entropy Oxides in the Mullite-Type Structure.

High-entropy materials (HEMs) represent a new class of solid solutions containing at least five different elements. Their compositional diversity makes them promising as platforms for the development of functional materials. We synthesized new HEMs in a mullite-type structure and present five compounds, i.

Influence of the Precursor Structure on the Formation of Tungsten Oxide Polymorphs.

Understanding material nucleation processes is crucial for the development of synthesis pathways for tailormade materials. However, we currently have little knowledge of the influence of the precursor solution structure on the formation pathway of materials. We here use total scattering to show how the precursor solution structure influences which crystal structure is formed during the hydrothermal synthesis of tungsten oxides.

Crystallography at non-ambient conditions and physical properties of the synthesized double perovskites, Sr(CoFe)TeO.

Polycrystalline double perovskite-type Sr(CoFe)TeO with various stoichiometric compositions ( = 0, 0.25, 0.5, 0.

Effects of iron substitution and anti-site disorder on crystal structures, vibrational, optical and magnetic properties of double perovskites Sr(FeNi)TeO.

The double-perovskite series, Sr(FeNi)TeO ( = 0, 0.25, 0.50, 0.

Understanding the role of flux, pressure and temperature on polymorphism in ThBO.

A novel polymorph of ThBO, denoted as β-ThBO, was synthesised under high-temperature high-pressure (HT/HP) conditions. single crystal X-ray diffraction measurements, β-ThBO was found to form a three-dimensional (3D) framework structure where thorium atoms are ten-fold oxygen coordinated forming tetra-capped trigonal prisms. The only other known polymorph of ThBO, denoted α, synthesised herein using a known borax, BO-NaBO, high temperature solid method, was found to transform to the β polymorph when exposed to conditions of 4 GPa and ∼900 °C.

π-Hole bonding in a new co-crystal hydrate of gallic acid and pyrazine: static and dynamic charge density analysis.

A new cocrystal hydrate of gallic acid with pyrazine (4GA, Py, 4HO; GAPyW) was obtained and characterized by single crystal X-ray diffraction. In addition to structure determination, experimental charge density analysis was carried out in terms of Multipole Modelling (MP), X-ray wavefunction refinement (XWR) and maximum entropy method (MEM). As a part of XWR, the structural refinement via Hirshfeld atom refinement was carried out and resulted in O-H bond lengths close to values from neutron diffraction.

BN-Substitution in Dithienylpyrenes Prevents Excimer Formation in Solution and in the Solid State.

Boron-nitrogen substitutions in polycyclic aromatic hydrocarbons (PAHs) have a strong impact on the optical properties of the molecules due to a significantly more heterogeneous electron distribution. However, besides these single-molecule properties, the observed optical properties of PAHs critically depend on the degree of intermolecular interactions such as π-π-stacking, dipolar interactions, or the formation of dimers in the excited state. Pyrene is the most prominent example showing the latter as it exhibits a broadened and strongly bathochromically shifted emission band at high concentrations in solution compared to the respective monomers.

Synthesis, Reactivity and Structural Properties of Trifluoromethylphosphoranides.

Phosphoranides are interesting hypervalent species which serve as model compounds for intermediates or transition states in nucleophilic substitution reactions at trivalent phosphorus substrates. Herein, the syntheses and properties of stable trifluoromethylphosphoranide salts are reported. [K(18-crown-6)][P(CF ) ], [K(18-crown-6)][P(CF ) F], and [NMe ][P(CF ) F ] were obtained by treatment of trivalent precursors with sources of CF or F units.

A Versatile Silver(I) Pentafluorooxosulfate Reagent for the Synthesis of OSF Compounds.

Herein, we report the preparation of silver(I) pentafluorooxosulfate from commercially available AgF and OSF . The compound is surprisingly stable in a MeCN solution. Apart from that, AgOSF has been stabilised by the addition of 2,2'-bipyridine ligands.

π-Conjugated stannole copolymers synthesised by a tin-selective Stille cross-coupling reaction.

The synthesis of four well-defined conjugated polymers containing unusual heterocycle units in the main chain, namely stannole units as building blocks, is reported. The stannole-thiophenyl copolymers were generated by tin-selective Stille coupling reactions in nearly quantitative yields of 94% to 98%. NMR data show that the tin atoms in the rings remain unaffected.

KLiRE(BO) (RE = Dy, Ho, Er, Tm, Yb, and Y): Structural, Spectroscopic, And Thermogravimetric Studies on a Series of Mixed-Alkali Rare-Earth Orthoborates.

We report a detailed structural, spectroscopic, and thermogravimetric investigation of a new series of mixed-alkali rare-earth orthoborates KLiRE(BO) (RE = Dy, Ho, Er, Tm, Yb, and Y). Single crystals were directly prepared by a flux method as well as mechanically separated from the polycrystalline powder obtained from the conventional solid-state reactions. All KLiRE(BO) members are isotypic and crystallize in the space group 2/.

Similarities and Differences between Crystal and Enzyme Environmental Effects on the Electron Density of Drug Molecules.

The crystal interaction density is generally assumed to be a suitable measure of the polarization of a low-molecular weight ligand inside an enzyme, but this approximation has seldomly been tested and has never been quantified before. In this study, we compare the crystal interaction density and the interaction electrostatic potential for a model compound of loxistatin acid (E64c) with those inside cathepsin B, in solution, and in vacuum. We apply QM/MM calculations and experimental quantum crystallography to show that the crystal interaction density is indeed very similar to the enzyme interaction density.

Taking a snapshot of the triplet excited state of an OLED organometallic luminophore using X-rays.

OLED technology beyond small or expensive devices requires light-emitters, luminophores, based on earth-abundant elements. Understanding and experimental verification of charge transfer in luminophores are needed for this development. An organometallic multicore Cu complex comprising Cu-C and Cu-P bonds represents an underexplored type of luminophore.

Synthesis and Thermal Investigations of Eleven-Membered Ring Systems Containing One of the Heavier Group 14 Element Atoms Si, Ge, and Sn.

Unique eleven-membered rings containing silicon, germanium, and tin were synthesized in good yields by the reactions of the corresponding 1,2-bis((2-bromothiophen-3-yl)methoxy)benzenes with (CH)ECl where E = Sn, Ge, Si. The Sn and Ge congeners were crystallized, but the conformers that these rings crystallized in, were quite different. As confirmed by Density Functional Theory (DFT) calculations, (CHOSSn) assumes a unique crystal structure that leaves more room around the tetrel atom as compared to the crystal structure of the corresponding Ge compound.

Complementary bonding analysis of the N-Si interaction in pentacoordinated silicon compounds using quantum crystallography.

The N-Si interaction in two pentacoordinated silicon compounds is investigated based on a complementary bonding analysis, which consists of bonding descriptors from real space and orbital space. These are derived from X-ray wavefunction refinements of high-resolution X-ray diffraction data of single crystals and from isolated-molecule theoretical wavefunctions. The two pentacoordinated compounds only differ in one methylene group, so that the amino substituent is more flexible in one of the structures, hence probing the attractive or repulsive character of the N-Si interaction.

An Old Dog with New Tricks - Additions to the Cesium Lithium Chloride System: CsLiCl and the Hydrated CsLiCl · 4HO.

The CsCl/LiCl system has been studied for over a century now. Numerous phases have been predicted - only three have hitherto been found. We present the synthesis and single-crystal structure of the cesium lithium pentachloride CsLiCl, predicted earlier but with a different structure.

Relativistic quantum crystallography of diphenyl- and dicyanomercury. Theoretical structure factors and Hirshfeld atom refinement.

Quantum crystallographic refinement of heavy-element-containing compounds is a challenge, because many physical effects have to be accounted for adequately. Here, the impact and magnitude of relativistic effects are compared with those of electron correlation, polarization through the environment, choice of basis set and treatment of thermal motion effects on the structure factors of diphenylmercury(II) [Hg(Ph)] and dicyanomercury(II) [Hg(CN)]. Furthermore, the individual atomic contributions to the structure factors are explored in detail (using Mulliken population analysis and the exponential decay of atomic displacement parameters) to compare the contributions of lighter atoms, especially hydrogen atoms, against mercury.