Crystal structure, optical characterization, conduction and relaxation mechanisms of a new hybrid compound (C6H9N2)2[Sb2Cl8].

Hybrid materials play a crucial role in the construction of flexible electronic devices due to the advantages of both organic and inorganic components. To this end, a new hybrid compound (C6H9N2)2[Sb2Cl8] was successfully fabricated using the slow evaporation solution growth approach at room temperature. In-depth research has been done on the structural, optical, and dielectric characteristics. This compound adopts the triclinic symmetry and crystallizes in the centrosymmetric space group P1̄. The inorganic and organic components respectively form anionic and cationic layers parallel to the ac-plane and alternate along the crystallographic b-axis. The [Sb2Cl8]2- dimeric units are bound to the 2-amino-5-picolinium cations [(C6H9N2)]+ through N-H⋯Cl hydrogen bonds. Optical absorption measurements showed a semiconductor behavior with a band gap of approximately 3.57 eV. In addition, DFT calculations were performed to investigate the absorption spectrum, wavelength, and HOMO-LUMO gap. The analysis of complex impedance spectra shows that the electrical conductivity of the sample is strongly frequency and temperature dependent, indicating a relaxation phenomenon and semiconductor-type behavior. Dielectric data obtained from complex impedance spectroscopy and ac conductivity with the use of the Maxwell-Wagner equivalent circuit model, and the universal power law have been investigated to explore the basic components of the electronic transport and relaxation process in our material.

[Vertebral osteomyelitis due to Candida tropicalis secondary to candidemia. A case report]. / Spondylodiscite à Candida tropicalis secondaire à une candidémie. À propos d'un cas.

Candida spp. vertebral osteomyelitis is rare. Clinical presentation is unspecific. Diagnosis requires mycological culture of a biopsy specimen. Therapeutic management is based on prolonged course of azole or liposomal amphotericin B. We report the case of Candida tropicalis vertebral osteomyelitis with epidural involvement in a 27 years-old male patient, followed for S-ß-thalassemia and with a history of candidemia. The fungus was isolated from a needle biopsy of the vertebral disk. The outcome was favorable under antifungal treatment by amphotericin B and voriconazole.

Monitoring dehydration of the organic-inorganic [(C3H7)4N][SnCl5(H2O)]·2H2O compound using simultaneous thermal and Raman studies.

In this work we report the experimental studies of the structural phase transition in the [(C3H7)4N]SnCl5(H2O)]·2H2O compound by differential scanning calorimetric (DSC) and Raman spectroscopic. The X-ray powder diffraction study of the [(C3H7)4N][SnCl5(H2O)]·2H2O sample at room temperature showed that this compound is monoclinic and has P121/c1 space group. Differential scanning calorimetric disclosed two types of phase transitions in the temperature range 356-376 (T1) K and at 393K (T2) characterized, by a loss of water molecules and probably a reconstruction of new anionic parts after T2 transition. The Raman scattering spectra recorded at various temperatures in the wavenumber range from 100 to 3800cm(-1) covering the domains of existence of changes in the vicinity of the two phase transitions detected by DSC measurement. A detailed study of the spectral parameters (wave number, reduced intensity and the full width at half maximum) as a function of temperature of a chosen band, associated with (νs(SnO)+νs(SnCl)), based on an order-disorder model allowed us to obtain information relative to the activation energy and correlation length.

Using Raman spectroscopy to understand the origin of the phase transitions observed in [(C3H7)4N]2Zn2Cl6 compound.

Phase transitions of the centrosymmetric compound, [(C3H7)4N]2Zn2Cl6, were studied by differential scanning calorimetry (DSC), X-ray diffraction, Raman spectroscopy and dielectric measurements. Two reversible order-disorder and displacive phase transitions are observed at T1=327K and T2=347K with 3K and 4K hysteresis respectively, indicating a first order character. The evolution of Raman line shifts, "ν", and the half-width, "Δν", versus temperature show some singularities associated with the transitions, suggesting that they are governed by the reorientational and the displacement of the organic part. Besides the results of the dielectric permittivity study confirms the conclusion drawn from the calorimetric and Raman measurements that the phase transition located in the vicinity of the temperature of the dielectric proprieties is characterized by change of dynamical state of cation.