Hexaaqua­cadmium(II) dipicrate monohydrate

In the structure of the title compound, [Cd(H2O)6](C6H2N3O7)2·H2O, the CdII ion is located on an inversion center and is coordinated by six water mol­ecules in an octa­hedral geometry. The picrate anions have no coordination inter­actions with the CdII ion. The three nitro groups are twisted away from the attached benzene ring, making dihedral angles of 17.89 (3), 27.94 (4) and 13.65 (3)°. There are numerous O—H⋯O hydrogen bonds in the crystal structure, involving coordinated and uncoordinated water molecules

Structural, vibrational and thermal studies of a new nonlinear optical material: L-Asparagine-L-tartaric acid

Crystals of a new nonlinear optical (NLO) material, viz., L-asparagine-L-tartaric acid (LALT)(1) were grown by slow evaporation of an aqueous solution containing equimolar concentrations of L-asparagine and t-tartaric acid. The structure of the title compound which crystallizes in the non-centrosymmetric monoclinic space group P2(1) consists of a molecule of L-asparagine and a molecule of free L-tartaric acid both of which are interlinked by three varieties of H-bonding interactions namely O-H center dot center dot center dot O, N-H center dot center dot center dot O and C-H center dot center dot center dot O. The UV-Vis-NIR spectrum of 1 reveals its transparent nature while the vibrational spectra confirm the presence of the functional groups in 1. The thermal stability and second harmonic generation (SHG) conversion efficiency of 1 were investigated. (C) 2012 Elsevier B.V. All rights reserved

Dynamic shock wave driven simultaneous crystallographic and molecular switching between alpha-Fe2O3 and Fe3O4 nanoparticles - a new finding

International audienceSwitchable nanostructured materials with a low-cost and fast processing have diverse practical applications in the modern electronic industries, but such materials are highly scarce. Hence, there is a great demand for identifying the externally stimulated solid-state switchable phase transition materials for several industrial applications. In this paper, we present the experimentally observed solid-state molecular level switchable phase transitions of nanocrystalline iron oxide materials: {alpha-Fe2O3 (R-3c) to Fe3O4 (Fd-3m) and Fe3O4 (Fd-3m) to alpha-Fe2O3 (R-3c)} under dynamic shock wave loaded conditions, and the results were evaluated by diffraction, and vibrational and optical spectroscopic techniques. To date, this is most probably the first report which demonstrates the simultaneous molecular and crystallographic switchable-phase-transitions enforced by dynamic shock waves such that the title material is proposed for sensors and molecular switching applications

Spin-singlet ground state of the coupled Jeff = 12 alternating chain system Sr2 Co(SeO3)3

© 2022 American Physical Society.We report a detailed study of the structural, magnetic, thermodynamic, and electronic properties of a coupled Jeff = 12 alternating chain Sr2Co(SeO3)3 compound using magnetic susceptibility χ(T), magnetic specific heat Cm(T), magnetization, and neutron diffraction measurements along with first-principles calculations. The first-principles calculations based on the density functional theory suggest that Sr2Co(SeO3)3 forms a quasi-one-dimensional chain with bond alternation and interchain interactions. χ(T), Cm(T), and neutron powder diffraction measurements confirm that no long-range magnetic ordering occurs down to 100 mK. Instead, a maximum in χ(T) and Cm(T) and an exponential drop of χ(T) and Cp(T) as T→0 K point to a spin-singlet ground state. The analysis of χ(T) and Cm(T) based on a J1-J2 alternating Heisenberg model shows the bond alternation α=J2/J1≈0.7 and a spin gap of Δ≈3 K. Our work demonstrates that Sr2Co(SeO3)3 is a coupled alternating chain system based on spin-orbit entangled Jeff = 12.11Nsciescopu