A Metatitanic Acid Particulate Xerogel: Green Synthesis, Structure Determination, and Detailed Characterization.

The manuscript focuses on an original method of preparation of metatitanic acid when only environmentally safe base substances are used in the synthesis process. The synthesis is based on the reaction of solid titanyl sulfate in an aqueous solution of sodium hydroxide. This method allows for (i) a full preservation of the morphology of the starting titanyl sulfate and (ii) a preparation of metatitanic acid substances with specific parameters.

Highly efficient eco-friendly sodium titanate sorbents of Cs(i), Sr(ii), Co(ii) and Eu(iii): synthesis, characterization and detailed adsorption study.

Development of useful all-around materials which can quickly and efficiently adsorb radionuclides in response to environmental radioactive contamination is an urgent research objective. In response to this need, our team developed a simple preparation method for stable sodium titanates which can serve as efficient agents for removal of radionuclides from water. With an emphasis on an environmentally friendly synthesis, the resulting materials were defined by a range of means and methods measuring pH, ionic strength, contact time or metal ion concentration in order to assess their potential for use and applications as sorbents.

Optimization of Chemical Bonding through Defect Formation and Ordering─The Case of MgPtGe.

The new phase MgPtGe (≡Mg□PtGe; □ = vacancy) was prepared by reacting a mixture of the corresponding elements at high temperatures. According to single crystal X-ray diffraction data, it adopts a defect variant of the lighter analogue MgPtSi (≡MgPtSi), reported in the LiCuAs structure. An ordering of the Mg vacancies results in a stoichiometric phase, MgPtGe.

A di‑iron(III) μ-oxido complex as catalyst precursor in the oxidation of alkanes and alkenes.

The oxido-bridged diiron(III) complex [Fe(μ-O)(μ-OAc)(DPEAMP)](OCH) (1), based on a new unsymmetrical ligand with an NO donor set, viz. [2-((bis(pyridin-2-ylmethyl)amino)methyl)-6-((ethylamino)methyl)-4-methylphenol (HDPEAMP)], has been prepared and characterized by spectroscopic methods and X-ray crystallography. The crystal structure of the complex reveals that each Fe(III) ion is coordinated by three nitrogen and three oxygen donors, two of which are the bridging oxido and acetate ligands.

Structure and stability of γ-AuZn: a γ-brass-related complex phase in the Au-Zn System.

γ-AuZn in the Au-Zn binary system has been synthesized and its structure analyzed by single-crystal X-ray diffraction. It crystallizes in the trigonal space group P31m (No. 157) with ∼227 atoms per unit cell and represents a \surd3a × \surd3a × c superstructure of rhombohedrally distorted γ-AuZn.

New Nonlinear Optical Crystal of Rhodamine 590 Acid Phthalate.

The synthesis and crystal structure of rhodamine 590 acid phthalate (RhAP) have been reported. This novel solid-state rhodamine derivative not only has a longer fluorescence lifetime compared to rhodamine solid-state matrixes where emission is quenched but also possesses strong nonlinear optical characteristics. The static and dynamic first- and second-order hyperpolarizabilities were calculated using the time-dependent density functional theory at the B3LYP/6-31+G* level.

Entropy-Driven Incommensurability: Chemical Pressure-Guided Polymorphism in PdBi and the Origins of Lock-In Phenomena in Modulated Systems.

Incommensurate order, in which two or more mismatched periodic patterns combine to make a long-range ordered yet aperiodic structure, is emerging as a general phenomenon impacting the crystal structures of compounds ranging from alloys and nominally simple salts to organic molecules and proteins. The origins of incommensurability in these systems are often unclear, but it is commonly associated with relatively weak interactions that become apparent only at low temperatures. In this article, we elucidate an incommensurate modulation in the intermetallic compound PdBi that arises from a different mechanism: the controlled increase of entropy at higher temperatures.

Highly-efficient removal of Pb(ii), Cu(ii) and Cd(ii) from water by novel lithium, sodium and potassium titanate reusable microrods.

In this work, we report on the efficient removal of heavy metal ions with nanostructured lithium, sodium and potassium titanates from simulated wastewater. The titanates were obtained a fast, easy and cost effective process based on extraction of sulfate ions from the crystals of titanyl sulfate and their replacement with hydroxyl groups of NaOH, LiOH and KOH solutions leaving the Ti-O framework intact. The as-prepared titanates were carefully examined by scanning and transmission electron microscopy.

β-LiZn: A Low Symmetric Polar Intermetallic Compound.

The crystal structure of the high-temperature modification of the compound LiZn was determined using single-crystal X-ray diffraction data. It is the first representative of a new binary structure type with triclinic space group 1̅, where the parameters of the unit cell are = 8.0073(3)Å, = 11.

A New Material with a Composite Crystal Structure Causing Ultralow Thermal Conductivity and Outstanding Thermoelectric Properties: TlAgTe.

A new state-of-the-art thermoelectric material, TlAgTe, which possesses an extremely low thermal conductivity of about 0.25 W m K and a high figure-of-merit of up to 1.1 at 525 K, was obtained using a conventional solid-state reaction approach.

The Mystery of the AuIn 1:1 Phase and Its Incommensurate Structural Variations.

In this communication, the AuIn 1:1 phase ( Naturwissenschaften , 1953 , 40 , 437 , DOI: 10.1007/BF00590353 ), and its ordering behavior at various temperatures is investigated. To enable the growth of a X-ray suitable specimen, a tempering routine was established by the interpretation of a differential scanning calorimetry (DSC) study.

In Situ Synthesis and Single Crystal Synchrotron X-ray Diffraction Study of ht-SnSb: An Example of How Complex Modulated Structures Are Becoming Generally Accessible.

Recent developments in X-ray sources and detectors and the parallel development of software for nonstandard crystallography has made analysis of very complex structural problems accessible to nonexperts. Here, we report the successful solution of the structure of ht-SnSb, an analysis that presents several challenges but that is still manageable in a relatively straightforward way. This compound exists only in a narrow temperature regime and undergoes an unquenchable phase transformation on cooling to room temperature; it contains two elements with close to identical scattering factors, and the structure is incommensurately modulated with four symmetry dependent modulation wave vectors.

Fe Hexa N-Heterocyclic Carbene Complex with a 528 ps Metal-to-Ligand Charge-Transfer Excited-State Lifetime.

The iron carbene complex [Fe(btz)](PF) (where btz = 3,3'-dimethyl-1,1'-bis(p-tolyl)-4,4'-bis(1,2,3-triazol-5-ylidene)) has been synthesized, isolated, and characterized as a low-spin ferrous complex. It exhibits strong metal-to-ligand charge transfer (MLCT) absorption bands throughout the visible spectrum, and excitation of these bands gives rise to a MLCT state with a 528 ps excited-state lifetime in CHCN solution that is more than one order of magnitude longer compared with the MLCT lifetime of any previously reported Fe complex. The low potential of the [Fe(btz)]/[Fe(btz)] redox couple makes the MLCT state of [Fe(btz)] a potent photoreductant that can be generated by light absorption throughout the visible spectrum.

A low-spin Fe(iii) complex with 100-ps ligand-to-metal charge transfer photoluminescence.

Transition-metal complexes are used as photosensitizers, in light-emitting diodes, for biosensing and in photocatalysis. A key feature in these applications is excitation from the ground state to a charge-transfer state; the long charge-transfer-state lifetimes typical for complexes of ruthenium and other precious metals are often essential to ensure high performance. There is much interest in replacing these scarce elements with Earth-abundant metals, with iron and copper being particularly attractive owing to their low cost and non-toxicity.

Exo-bonded six-membered heterocycle in the crystal structures of RECoGe (RE = La-Nd).

In this article four new ternary phases of RECoGe (RE = La-Nd) are reported. They were synthesized by a solid-state reaction of the elements at high temperature, and their crystal structures were investigated by single crystal X-ray diffraction data. The isostructural phases crystallize in a new monoclinic structure type, space group P2/c, Z = 4, Pearson code mP52, and Wyckoff sequence e.

A smectic dodecagonal quasicrystal.

We report a solid smectic phase that exhibits dodecagonal global order. It is composed of axially stacked hexagonally ordered particle layers, and its 12-fold rotational symmetry induced by the 30° rotation of adjacent layers with respect to each other. A quasicrystal was produced in a molecular-dynamics simulation of a single-component system of particles interacting via a spherically-symmetric potential.

Antimalarial activity of ruthenium(II) and osmium(II) arene complexes with mono- and bidentate chloroquine analogue ligands.

Eight new ruthenium and five new osmium p-cymene half-sandwich complexes have been synthesized, characterized and evaluated for antimalarial activity. All complexes contain ligands that are based on a 4-chloroquinoline framework related to the antimalarial drug chloroquine. Ligands HL(1-8) are salicylaldimine derivatives, where HL(1) = N-(2-((2-hydroxyphenyl)methylimino)ethyl)-7-chloroquinolin-4-amine, and HL(2-8) contain non-hydrogen substituents in the 3-position of the salicylaldimine ring, viz.

Synthesis, crystal structure, and bonding analysis of the hypoelectronic cubic phase Ca5Pd6Ge6.

The title compound, Ca5Pd6Ge6, was obtained during a systematic investigation of the Ca-Pd-Ge ternary phase diagram. The crystal structure was determined and refined from single-crystal X-ray diffraction data. It crystallizes in a new structure variant of the Y4PdGa12-type structure (Im3̅m, a = 8.

A heteroleptic ferrous complex with mesoionic bis(1,2,3-triazol-5-ylidene) ligands: taming the MLCT excited state of iron(II).

Strongly σ-donating N-heterocyclic carbenes (NHCs) have revived research interest in the catalytic chemistry of iron, and are now also starting to bring the photochemistry and photophysics of this abundant element into a new era. In this work, a heteroleptic Fe(II) complex (1) was synthesized based on sequentially furnishing the Fe(II) center with the benchmark 2,2'-bipyridine (bpy) ligand and the more strongly σ-donating mesoionic ligand, 4,4'-bis(1,2,3-triazol-5-ylidene) (btz). Complex 1 was comprehensively characterized by electrochemistry, static and ultrafast spectroscopy, and quantum chemical calculations and compared to [Fe(bpy)3](PF6)2 and (TBA)2[Fe(bpy)(CN)4].

Cu3Sn - understanding the systematic absences.

The intermetallic compound Cu3Sn has previously been described as a long-period antiphase boundary superstructure of the Cu3Ti structure type. While the compound itself has been reported as a tenfold and an eightfold superstructure, ternary doped alloys show shorter repetitions. Interestingly, the diffraction patterns of these compounds show non-crystallographic absences that cannot be explained using the superstructure models.

A short designed semi-aromatic organic nanotube--synthesis, chiroptical characterization, and host properties.

The first generation of an organic nanotube based on the enantiomerically pure bicyclo[3.3.1]nonane framework is presented.

Synthesis and crystal structure of a series of incommensurately modulated composite oxohalide compounds.

Transparent, needle-like single crystals of the isostructural compounds [Sb4O7+3δX4][Zn3]1+δ (X = Cl, Br, I) δ ≈ 0.2 were obtained from chemical reactions in evacuated and sealed silica tubes. First, the average structure was solved in P21/n but the model refined poorly and a lowering of the symmetry to the 3 + 1 dimensional space group P21(α0γ)0 gave a significantly better fit to the data.

AuCd4: a Hume-Rothery Phase with VEC of 1.8 and icosahedral and trigonal-prismatic clusters as building blocks.

The η phase in the Au-Cd binary system has been synthesized, and the structure has been analyzed by single-crystal X-ray diffraction. The compound η-AuCd(4) crystallizes in the hexagonal space group P6(3)/m (No. 176).

Valence state driven site preference in the quaternary compound Ca5MgAgGe5: an electron-deficient phase with optimized bonding.

The quaternary phase Ca5Mg0.95Ag1.05(1)Ge5 (3) was synthesized by high-temperature solid-state techniques, and its crystal structure was determined by single-crystal diffraction methods in the orthorhombic space group Pnma-Wyckoff sequence c(12) with a = 23.