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This study focuses on the synthesis and characterization of the novel Ni(II)(L-threoninato)2(H2O)2 crystal, a bivalent transition metal complex based on Ni(II) ions, based on crystalline structure and thermal properties. Through crystallographic analysis, we reveal that Ni(II)(L-threoninato)2(H2O)2 complex adopts an orthorhombic system with the C2221 space group. To gain insights into its thermal behavior, thermogravimetric analysis, and differential scanning calorimetry techniques were employed to estimate kinetic parameters related to its thermal degradation. Model-free analysis, employing Friedman, Ozawa-Flynn-Wall, and Kissinger-Akahira-Sunose methods, along with model-based analysis, were utilized to evaluate the activation energy and the logarithm of the pre-exponential factor. Furthermore, we elucidated the complex's crystalline structure thermal behavior using Powder X-ray Diffraction measurements as a function of temperature, at air and under vacuum. No phase transitions were detected at low temperatures only at high temperatures due to loss of water molecules. The measurements showed the crystal goes to a partially crystalline anhydrous phase with a certain long-range order in the [001] direction. Through Rietveld refinement the behavior of the lattice parameters and thermal expansion coefficients were obtained. This comprehensive study provides valuable knowledge about the Ni(II)(L-threoninato)2(H2O)2 crystals and lays the foundation for further exploration of similar complexes. 3D-plot of the thermal decomposition showing the TGA curve and the IR spectra of the released gases. XRD pattern showing the crystal keeps a long-range order in the [001] direction during the water loss partial amorphization. Thermal behavior of lattice parameters obtained by Rietveld refinement. [Display omitted] • Synthesis and crystal structure of the novel Ni(II)(L-threoninato) 2 (H 2 O) 2 crystal. • Thermal behavior of the Ni(II)(L-threoninato) 2 (H 2 O) 2 crystal by means of PXRD. • Thermal behavior and kinetic studies using TGA and DSC analysis. • Thermal expansion coefficients in air atmosphere and also under vacuum. • Partially crystalline anhydrous phase with long-range order in [001] direction. [ABSTRACT FROM AUTHOR]

Abstract: We report the preparation and characterization by elemental analysis, infrared (IR), single crystal X-ray diffraction, magnetic measurements and electron paramagnetic resonance (EPR) of the new compound catena-poly[copper(II)-μ-dichloro-l-lysine]hemihydrate, with formula C6H14Cl2CuN2O2·(H2O)0.5, here after called [Cu(lys)Cl2]. The compound crystallizes in the space group C2 with copper ions in a square pyramidal coordination, and the structure consists of zigzag chains along the b axis bridged by equatorial-apical chlorine bonds with Cu–Cu distance of 3.5414(4)Å, and a small Cu–Cl–Cu angle of 85.47(6)°. Magnetic susceptibility and isothermal magnetization curves reveals a weak antiferromagnetic interaction 2J =−0.30(2)cm−1 supported by the Cu–Cl–Cu bridge connecting CuII neighbors in the chains. EPR spectra at 34.0GHz were obtained in powdered samples and in a single crystal with B 0 in three orthogonal planes. Assuming an axially symmetric molecular g -matrix, we obtained principal g-values g // =2.2794(9) and from the crystal g-matrix calculated using the observed angular variation of the EPR line position. The angular variation of the line width, largest along the chain direction, is attributed to dipolar couplings between CuII ions in the lattice. The magnetic and EPR results are discussed in terms of the exchange couplings. [Copyright &y& Elsevier]

The potential of tert -butyl hydroperoxide as a reagent in the guanylation of benzoylthioureas in the presence of amines has been evaluated in a systematic study involving substrates bearing N 2 -substituents with different electronic properties. The results show that t BuOOH is a suitable and robust reagent for the synthesis of either N 1 , N 2 , N 3 -tri- and tetrasubstituted or N 1 , N 2 -disubstituted guanidines from N 2 -substituted N 1 -benzoylthioureas and N 1 -benzoylthioureas, respectively. The recrystallised guanylation adducts were readily obtained in good yields and at high purity levels after a simple one-pot reaction procedure. The crystal structures of two novel benzoylguanidines are provided. [ABSTRACT FROM AUTHOR]