A new hybrid compound based on mercury and 3,3′-diaminobiphenylsulfone studied by a combined experimental and theoretical approach

Crystal structure, Hirshfeld surface analysis, conduction mechanism and electrical modulus study of the new organic-inorganic compound [C8H10NO]2HgBr4

There has been a lot of interest in the development of a novel hybrid material based on mercury that has fascinating structural properties. In this paper, single crystals of [C8H10NO]2HgBr4 was successfully synthesized by the slow evaporation method at room temperature. In fact, the latter crystallizes in the orthorhombic system (Cmca space group) with cell parameters a = 20.824(2) Å, b = 15.352(1) Å and c = 13.700(1) Å and Z = 8. Its structure is constituted by one [C8H10NO]+ cation and one type of isolated anion [HgBr4]2- tetrabromomercurate(ii). The atomic arrangement presents an alternation of organic and inorganic layers along the a-axis. To maintain the cohesiveness of the structure, these components are joined via π⋯π interactions and hydrogen bonds (N-H⋯Br and N-H⋯O). A general network of hydrogen bonds ensures the interconnection of several entities. Greater knowledge of these interactions has been obtained based on the Hirshfeld surface analysis and 2D fingerprint plots. The analysis of complex impedance spectra shows that the electrical properties of the material are heavily dependent on frequency and temperature. The obtained results were analyzed by fitting the experimental data to an equivalent circuit model. The temperature dependence of conductivity and the relaxation frequency ωmax fulfill the Arrhenius relation and activation energies are estimated. The material follows Jonscher's universal dynamic law or here there is a decrease in the exponent 's' as the temperature increases. This result indicates that the Correlated Barrier Hopping (CBH) model represents the conduction mechanism. Besides, the non-Debye type conductivity relaxation is revealed by the electrical modulus analysis.

Crystal structure, spectroscopic measurement, optical properties, thermal studies and biological activities of a new hybrid material containing iodide anions of bismuth(iii)

As part of our interest in halogenobismuthate(iii) organic-inorganic hybrid materials, a novel compound named bis(4,4'-diammoniumdiphenylsulfone) hexadecaiodotetrabismuthate(III) tetrahydrate with the chemical formula (C₁₂H₁₄N₂O₂S)₂[Bi₄I₁₆]·4H₂O, abbreviated as (H₂DDS)[Bi₄I₁₆], has been prepared by a slow evaporation method at room temperature. This compound was characterized by single crystal X-ray diffraction (SCXRD), spectroscopic measurements, thermal study and antimicrobial activity. The examination of the molecular arrangement shows that the crystal packing can be described as made of layers of organic [C₁₂H₁₄N₂O₂S]²⁺ entities and H₂O molecules, between which tetranuclear [Bi₄I₁₆]^4- units, isolated from each other, are inserted. The cohesion among the different molecules is assured by N-H⋯I, N-H⋯O and O-H⋯I hydrogen bonding interactions, forming a three-dimensional network. Room temperature IR, Raman spectroscopy of the title compound were recorded and analyzed. The optical properties were also investigated by both UV-vis and photoluminescence spectroscopy. Moreover, the synthesized compound was also screened for in vitro antimicrobial (Gram-positive and Gram-negative) and antioxidant activities (scavenging effect on DPPH free radicals, reducing power and total antioxidant capacity).