STUDY THE STABLE STRUCTURES OF ScGe6 BY GA-DFT AND THE CO ADSORPTION ON ScGe6− CLUSTER

The structures of ScGe6 and ScGe6− clusters were investigated by a combination of genetic algorithm with quantum chemical calculations (GA-DFT and DLPNO-CCSD(T)). Results show that the two most stable isomers of the ScGe6 cluster have a pentagonal bipyramid structure with a Sc atom at the vertex and a Ge atom capping the face of tetragonal bipyramid with a Sc atom at the vertex with Cs symmetry. The pentagonal bipyramid with the scandium atom at the vertex with C5v symmetry is the most stable ScGe6− cluster. The CO adsorption on the most stable isomer of the anionic cluster was studied by PBE functional. The isomer A1 of ScGe6− cluster can adsorb CO molecule as well. The most stable structure has CO along with the Sc-Ge bond. In two adsorption models at the Sc atom along the main axis, the Sc-CO adsorption model is more favorable than the Sc-OC model.

Scanning Electron Microscopy Coupled with Energy Dispersive Spectrometric Analysis Reveals for the First Time Weddellite and Sylvite Crystals on the Surface of Involucral Bracts and Petals of two Xeranthemum L. (Compositae) Species

In this work, weddellite and sylvite crystals are identified for the first time on the involucral bracts and petals of Xeranthemum annuum and Xeranthemum cylindraceum using scanning electron microscopy coupled with energy dispersive spectrometric (SEM-EDS) analysis. Well-developed crystals of weddellite (CaC2O4·2H2O) occur in the form of a tetragonal bipyramid (hhl), rarely in combination of a bipyramid and tetragonal prism (h00). Indumentum of involucral bracts of X. cylindraceum consists of nonglandular and glandular trichomes. Sylvite (KCl) crystals are observed only on the petal surface of X. cylindraceum. The crystals of sylvite occur in the form of perfect cubes (hexahedrons), but some crystals are deformed, i.e., partially elongated. Taxonomic significance of investigated microcharacters as well as the use of SEM-EDS analysis in taxonomic studies of plants are discussed.

Thieno[3,2-c]Pyridine Complex of Ni(II) with Unusual Magnetic Properties

Thieno[3,2-c]pyridine (thpy) has been prepared in a free form and embodied into the [Ni(thpy)2(H2O)2(ac)2] complex as a ligand. The X-ray structure shows a molecular structure of the complex with Ni−O(ac) = 2.059, Ni−OH2 = 2.078, and Ni−N(thpy) = 2.124 Ǻ. Electronically the complex behaves like a compressed tetragonal bipyramid. The molecular units are linked into a complex system of hydrogen bonds. Two units show a π−π stacking of the aromatic rings (3.8 Ǻ). There are planes of tetragons formed of the nickel atom with the in-plane Ni...Ni separation of 7.74 Ǻ and the inter-plane Ni...Ni contacts at a = 9.65 Ǻ. The effective magnetic moment shows a gradual decrease on cooling from the room temperature and an abrupt drop below 20 K typical for the zero-field splitting of S = 1 systems. Above the room temperature the effective magnetic moment shows anomalies – a decrease and then an increase.

A sol-hydrothermal route to truncated tetragonal bipyramid nanocrystals and hierarchical hollow microspheres of anatase TiO2 for application in dye-sensitized solar cells

DSSCs based on TiO2 bilayer photoanodes made of truncated tetragonal bipyramids and hierarchical hollow microspheres delivered a PCE of 9.06%.

A two-dimensional four-fold symmetric SrMoO4 dendrite

The morphology evolution of SrMoO4 microcrystals was obtained from a tetragonal bipyramid to a 3-D cross-like dendrite, and finally to a 2-D four-fold symmetric dendrite.