Bis(1H-pyrazole-κN 2)bis­(2,4,6-tri­isopropyl­benzoato-κO)cobalt(II)

The title compound, [Co(C16H23O2)2(C3H4N2)2] or (C3H4N2)2Co(O2CC6H2 iPr3-2,4,6), is a rare example of a tetra­coordinate cobalt(II) carboxyl­ate stabilized by ancillary N-heterocyclic ligands. The Co(II) ion resides on a crystallographic twofold axis so that the asymmetric unit comprises one half-mol­ecule. Due to the steric bulk of the 2,4,6-triisopropyl­phenyl substituents, the carboxyl­ate ligands are both coordinated in a monodentate fashion despite the low coordination number. The coordination geometry around the central Co(II) ion is distorted tetra­hedral with angles at Co ranging from 92.27 (18)° to 121.08 (14)°

Tris(N,N′-diisopropyl­benzamidinato)cerium(III)

The title compound, [Ce(C13H19N2)3], was obtained in moderate yield (67%) by treatment of anhydrous cerium trichloride with three equivalents of Li[PhC(NiPr)2] in tetra­hydro­furan. It is the first homoleptic lanthanide complex of this amidinate ligand. The central CeIII ion is coordinated by three chelating benzamidinate anions in a distorted octa­hedral fashion, with Ce—N distances in the narrow range 2.482 (2)–2.492 (2) Å. The dihedral angles between the phenyl rings and the chelating N—C—N units are in the range 73.3–87.9°, thus preventing conjugation between the two π-systems. The mol­ecule is located on a twofold rotation axis, and one of the phenyl rings is equally disordered over two alternative symmetry-equivalent positions around this axis

trans-Bis(perchlorato-κO)tetra­kis(1H-pyrazole-κN 2)copper(II)

The title compound, [Cu(ClO4)2(C3H4N2)4], was obtained unexpectedly by the reaction of copper(II) perchlorate hexa­hydrate with equimolar amounts of 1-chloro-1-nitro-2,2,2-tripyrazolylethane in methanol solution. The crystal structure comprises octa­hedrally coordinated Cu2+ ions, located on an inversion centre, with four pyrazole ligands in the equatorial plane. The average Cu—N distance is 2.000 (1) Å. Two perchlorate ions are coordinated to copper in trans positions [Cu—O = 2.4163 (11) Å]

[{μ-Cy 8 Si 8 O 13 } 2 Ca(DME)Ca(THF) 2 ] ؊ The First Metallasilsesquioxane Derivative of a Heavier Alkaline Earth Metal

Abstract. [{μ-Cy 8 Si 8 O 13 } 2 Ca(DME)Ca(THF) 2 ] (2), the first metallasilsesquioxane derivative of a heavier alkaline earth metal, has been prepared by a reaction of Cy 7 Si 7 O 9 (OH) 3 (1) with metallic Ca in liquid ammonia / THF followed by recrystallization from DME. In the course of the reaction ligand rearrangement under formation of the (Cy 8 Si 8 O 13 ) Ϫ dianion takes place. In the dinuclear calciu

1,2,3-Triphenyl-1,2-dihydro­quinoxaline

The title compound, C26H20N2, first reported in 1891, was obtained as a by-product in the preparation of benzildianil from benzil and excess aniline. The dihedral angles between the fused benzene ring and the pendant phenyl rings are 17.93 (11), 53.18 (10) and 89.08 (12)°

1,2,3,4-Tetra­methyl­cyclo­pent-2-ene-1,4-diol

The title compound, C9H16O2, crystallizes with two mol­ecules in the asymmetric unit. The structure displays inter­molecular O—H⋯O hydrogen bonding

Temperature dependent second-order Raman scattering in CuI

We report second-order Raman scattering spectra of copper iodide bulk single crystals aside from the fundamental TO and LO mode. The spectral shape was reproduced by a 2-phonon density of states calculated by DFT. Characteristic multi-phonon features were identified and assigned to combination, overtone and difference modes. In this way, the energy of acoustic zone-boundary phonons was determined. The temperature dependence of those modes and the fundamental optical phonons was analyzed by means of phonon-phonon interactions and lattice expansion effects up to room temperature. Processes related to the mode energy shift and width were identified for phonons at high symmetry points. The shifts due to lattice expansion are in accordance with the predictions by DFT in quasi-harmonic approximation using PBEsol functional.Comment: 11 pages, 6 figures, 3 tables. Submitted to Phys. Rev.

Coordination Chemistry of Acrylamide 2. Classical Complexes of Acrylamide with Manganese(II), Iron(II) and Nickel(II) Chlorides: Syntheses and Crystal Structures

Abstract. Metal complexes of manganese(II), iron(II), and nickel-(II) chlorides with acrylamide, [M(O-OC(NH 2 )CHϭCH 2

Lasing in cuprous iodide microwires

We report on the observation of lasing in cuprous iodide (CuI) microwires. A vapor-phase transport growth procedure was used to synthesize CuI microwires with low defect concentration. The crystal structure of single microwires was determined to be of zincblende-type. The high optical quality of single microwires is indicated by the observed series of excitonic emission lines as well as by the formation of gain under optical excitation. Lasing of triangular whispering-gallery modes in single microwires is demonstrated for fs- and ns-excitation from cryogenic temperatures up to 200 K. Timeresolved micro-photoluminescence studies reveal the dynamics of the laser process on the time scale of several picoseconds