Ionic behavior, Na+ mobility and infrared spectroscopy in Na7Cr4(P2O7)4PO4 material

The title compound, heptasodium tetrachromium(III) tetrakis(diphosphate) orthophosphate, was synthesized by solid state reaction. Its structure is isotypic with that of Na7M4(P2O7)4PO4 (M = In, Al) compounds and is made up from a three-dimensional [(CrP2O7)4PO4]7- framework with channels running along [001]. The Na+ cations are located in the voids of the framework. This compound has been investigated by X-ray diffraction and infrared (IR) spectroscopy. The conductivity measurements of the compound were carried out from 515 to 795 Kelvin using the frequency response analyzer with 0.05V amplitude signal over the range of 13MHz-5Hz. The conductivity of the sample at 574K is 0.45 10-6 S.cm-1. The activation energy Ea=0.73eV shows that Na7Cr4(P2O7)4PO4 is a medium ionic conductors. The monovalent cations conduction pathways in the crystal bulks are simulated by means of the bond valence model (BVS)

Structure cristalline de type alluaudite K0.4Na3.6Co(MoO4)3

A new triple molybdate, potassium sodium cobalt tris(molybdate), K0.4Na3.6Co(MoO4)3, was synthesized using solid-state reactions. The Co2+ and one Na+ cation are located at the same general site, each with occupancy 0.5. Another site (site symmetry 2) is occupied by Na+ and K+ cations, with occupancies of 0.597 (7) and 0.402 (6), respectively. The other two Na+ cations and one of the two Mo atoms lie on special positions (site symmetries -1, 2 and 2, respectively). The structure is characterized by M2O10 (M = Co/Na) dimers, which are linked by MoO4 tetrahedra, forming infinite layers. The latter are connected firstly by insertion of one type of MoO4 tetrahedra and secondly by sharing corners with the other type of MoO4 tetrahedra. This results in an open three-dimensional framework with the cavities occupied by the Na+ and K+ cations. The structure is isotypic with Na3In2As3O12 and Na3In2P3O12. A comparison is made with structures such as K2Co2(MoO4)3 and β-NaFe2(MoO4)3 and their differences are discussed

Na3Al(AsO4)2

The structure of the title compound trisodium aluminium bis(arsenate), Na3Al(AsO4)2, is built up from AlO4 and AsO4 corner-sharing tetrahedra, forming an undulating two-dimensional framework parallel to (100). The layers are constituted of large Al6As6O36 rings made up from six AlO4 and AsO4 tetrahedra in which two sodium cations are situated, the third sodium cation being located in the interlayer space. The structural relationships between the title compound and Na3Fe(PO4)2, NaAlCo(PO4)2 and Al5Co3(PO4)8 are discussed

Crystal structure of alluaudite-type Na4Co(MoO4)3

The title compound, tetrasodium cobalt(II) tris[molybdate(IV)], was prepared by solid-state reactions. The structure is isotypic with Na3In2(AsO4)3 and Na3In2(PO4)3. The main structural feature is the presence of infinite chains of edge-sharing X2O10 (X = Co/Na) dimers, which are linked by MoO4 tetrahedra, forming a three-dimensional framework enclosing two types of hexagonal tunnels in which Na+ cations reside. In this alluaudite structure, Co and Na atoms are located at the same general site with occupancies of 0.503 (5) and 0.497 (6), respectively. The other three Na and one of the two Mo atoms lie on special positions (site symmetries 2, -1, 2 and 2, respectively). The structure is compared with similar structures and other members of alluaudite family

First Zinc Bromide Promoted Annulative Domino Reactions between Enamines and Cyclic Morita–Baylis–Hillman Alcohols: Synthesis of N,O-Ketals

International audienceA new efficient ZnBr2-mediated annulative domino reaction between enamines and cyclic Morita–Baylis–Hillman (MBH) alcohols is disclosed. The process involves a tandem sequence (intermolecular conjugate addition of enamines to MBH alcohols and intramolecular nucleophilic addition of the hydroxyl moiety to the transiently generated iminium ion), affording the corresponding N,O-ketals diastereoselectively in good yields

Structural study, spectroscopic characterization, DFT calculations and electrical properties of manganese (II) organic-inorganic hybrid material (C8H14N2)2[MnCl4(H2O)2]Cl2

The new organic-inorganic compound, (C8H14N2)2[MnCl4(H2O)2]Cl2 denoted (1), crystallizes at room temperature in the monoclinic system, P21/c space group. The structure exhibits an alternate organic-inorganic layered stacking along a-axis. The inorganic layers formed by [MnCl4(H2O)2]2− anion and two uncoordinated chlorine anions. The organic layers are made of protonated m-Xylylenediamine (C8H14N2)2+. Crystal cohesion is achieved through Nsingle bondH…Cl and Osingle bondH…Cl hydrogen bonds building up a three-dimensional network. The functional groups present in the crystal were studied by FTIR. The optical proprieties were investigated by UV-visible spectroscopy study and the electronic properties HOMO and LUMO energies were calculated by TD-DFT. Thermal behavior (DSC, DTA/TGA) was also performed, while the composition of the phase was verified by semi-quantitative analysis (EDX). Hirshfeld surface (3D-HS) analysis and the two-dimensional fingerprint plots (2D-FP) affirms that the structure is dominated by H…Cl/Cl…H and H…H contacts. Electrical analysis of our compound has been investigated using complex impedance spectroscopy (CIS) in frequency and temperature range 3 uHz-20 MHz and 393–443 K, respectively. Impedance spectroscopy studies show that electrical-conductivity is 1.80 10−6 S cm−1 at 443 K and the activation energy is 2.15 eV