Natalia Usenko

Enthalpies of mixing in liquid alloys of iron with the lanthanides

Abstract The enthalpies of mixing in binary liquid alloys of iron with the lanthanides (Pr, Nd, Gd, Tb, Dy and Lu) were determined at 1550–1950 K by means of isoperibolic calorimetry. They show exothermic effects (in the Fe–Pr system partially endothermic) which increase across the lanthanides row from the Fe–Pr system (ΔHmin = −0.35 ± 0.10 kJ · mol−1 at xPr = 0.22; ΔHmax = 0.75 ± 0.24 kJ · mol−1 at xPr = 0.76; T = 1829 K) to the Fe–Lu system (ΔHmin = −11.58 ± 0.50 kJ · mol−1 at xLu = 0.35; T = 1950 K).

Mixing enthalpies in binary Ce-Sb and ternary Ce-Co-Sb liquid alloys

Abstract The enthalpies of mixing in liquid alloys in the binary Ce-Sb and ternary Ce-Co-Sb systems were determined over a wide range of composition by means of isoperibolic calorimetry in the temperature range 1 600-1 723 K. The minimum value of the integral enthalpy of mixing (ΔHmin) in the Ce-Sb system was evaluated to be −123 kJ mol-1 at xCe = 0.55. The enthalpies of mixing in liquid ternary alloys were found to increase smoothly from the binary boundary systems Co-Ce and Co-Sb towards the Ce-Sb system reaching the value of approximately −123 kJ mol-1 in the vicinity of the phase CeSb.

cis-Tetra­chloridobis(1H-imidazole-κN3)platinum(IV)

In the title complex, cis-[PtCl4(C3H4N2)2], the PtIV ion lies on a twofold rotation axis and is coordinated in a slightly distorted octahedral geometry. The dihedral angle between the imidazole rings is 69.9 (2)°. In the crystal, molecules are linked by N—H⋯Cl hydrogen bonds, forming a three-dimensional network.

Poly[bis­[μ4-N-(2-hydroxy­imino­propion­yl)-N′-(2-oxidoimino­propion­yl)propane-1,3-diaminato]dimethano­lcalciumdicopper(II)]

In the title compound, [CaCu2(C9H13N4O4)2(CH3OH)2]n, the CaII atom lies on an inversion center and is situated in a moderately distorted octahedral environment. The CuII atom is in a distorted square-pyramidal geometry, defined by four N atoms belonging to the amide and oxime groups of the triply deprotonated residue of N,N′-bis(2-hydroxyiminopropanoyl)propane-1,3-diamine (H4pap) and one oxime O atom from a neighboring Hpap ligand at the apical site, forming a dimeric [Cu2(Hpap)2]2− unit. Each dimeric unit connects four Ca atoms and each Ca atom links four [Cu2(Hpap)2]2− units through Ca—O(amide) bonds, leading to a three-dimensional framework. The crystal structure involves intra- and intermolecular O—H⋯O hydrogen bonds.

Enthalpies of mixing in binary Mn–In and ternary Mn–In–Gd liquid alloys

Abstract The enthalpies of mixing in liquid alloys of the binary Mn–In and ternary Mn–In–Gd systems were determined over a wide range of compositions by means of isoperibolic calorimetry in the temperature range 1 500 – 1 650 K. The enthalpies of mixing in the Mn–In system demonstrate endothermic effects (ΔHmax = 4.66 ± 0.38 kJ · mol−1 at xIn = 0.40). The enthalpies of mixing in the liquid ternary Mn–In–Gd alloys were determined along six sections (xMn/xIn = 0.22/0.78; 0.44/0.56; 0.65/0.35 and 0.83/0.17 for xGd changed from 0 up to 0.5 and xMn/xGd = 0.30/0.70; 0.60/0.40 for xIn changed from 0 up to 0.3). Enthalpies of mixing in the ternary system were found to be predominantly exothermic and steadily increasing in absolute values towards the Gd–In boundary binary system, reaching the maximum value in the vicinity of the phase GdIn.

Enthalpies of mixing in binary liquid alloys of lutetium with 3d metals

Abstract The enthalpies of mixing in binary liquid alloys of lutetium with chromium, cobalt, nickel and copper were determined at 1 773 – 1 947 K by isoperibolic calorimetry. The enthalpies of mixing in the Lu–Cr melts (measured up to 40 at.% Cr) demonstrate endothermic effects (ΔH = 6.88 ± 0.66 kJ · mol−1 at xLu = 0.60), whereas significant exothermic enthalpies of mixing have been established within a wide composition region for the Co–Lu, Ni–Lu and Cu–Lu liquid alloys. Minimum values of the integral enthalpy of mixing are as follows: ΔHmin = −23.57 ± 1.41 kJ · mol−1 at xLu = 0.38 for the Co–Lu system; ΔHmin = −48.65 ± 2.83 kJ · mol−1 at xLu = 0.40 for the Ni–Lu system; ΔHmin = −24.63 ± 1.52 kJ · mol−1 at xLu = 0.37 for the Cu–Lu system.

Enthalpies of mixing in binary Fe–Sb, Ce–Fe and ternary Ce–Fe–Sb liquid alloys

Abstract The enthalpies of mixing in liquid alloys in the binary Fe–Sb, Ce–Fe and ternary Ce–Fe–Sb systems were determined over a wide range of composition by means of isoperibolic calorimetry in the temperature range 1600–1830 K. The minimum values of the integral enthalpy of mixing (ΔHmin) were determined to be (−2.32 ± 0.22) kJ · mol−1 at xSb = 0.5 in the Fe–Sb system, and (−0.97 ± 0.19) kJ · mol−1 at xCe = 0.35 in the Ce–Fe system. The enthalpies of mixing in liquid ternary Ce–Fe–Sb alloys were found to increase smoothly from the binary boundary systems Ce–Fe and Fe–Sb towards the Ce–Sb system, reaching the minimum value of (−107.5 ± 3.6) kJ · mol−1 in the vicinity of the phase CeSb.

Poly[μ-aqua-diaquabis­[μ-2-cyano-2-(oxidoimino)­acetato]­copper(II)dipotassium]

In the title compound, [CuK2(C3N2O3)2(H2O)3]n, the Cu2+ atom is in a distorted square-pyramidal coordination geometry. Two N atoms belonging to the oxime groups and two O atoms belonging to the carboxylate groups of two trans-disposed doubly deprotonated residues of 2-cyano-2-(hydroxyimino)acetic acid make up the basal plane and the apical position is occupied by the water molecule. The neighboring Cu-containing moieties are linked into a three-dimensional framework by K—O and K—N contacts formed by two potassium cations with the carboxylate and the oxime O atoms and the nitrile N atoms of the ligand. The environments of the K+ cations are complemented to octa- and nonacoordinated, by K—O contacts with H2O molecules. The crystal structure features O—H⋯O hydrogen bonds.

cis-Bis(2,2'-bipyridine-κN,N')bis-(dimethyl sulfoxide-κO)zinc bis-(tetra-phenyl-borate) dimethyl sulfoxide monosolvate.

In the mononuclear title complex, [Zn(C10H8N2)2(C2H6OS)2](C24H20B)2·C2H6OS, the ZnII ion is coordinated by four N atoms of two bidentate 2,2′-bipyridine molecules and by the O atoms of two cis-disposed dimethyl sulfoxide molecules in a distorted octahedral geometry. The S atom and the methyl groups of one of the coordinated dimethyl sulfoxide molecules are disordered in a 0.509 (2):0.491 (2) ratio. The crystal packing is stabilized by C—H⋯O hydrogen bonds between the dimethyl sulfoxide solvent molecules and tetraphenylborate anions.

μ-Oxalato-bis­[(2,2′-bipyridyl)­copper(II)] bis(perchlorate) dimethyl­formamide disolvate monohydrate

The title compound, [Cu2(C2O4)(C10H8N2)4](ClO4)2·2C3H7NO·H2O, contains doubly charged centrosymmetric dinuclear oxalato-bridged copper(II) complex cations, perchlorate anions, and DMF and water solvate molecules. In the complex cation, the oxalate ligand is coordinated in a bis-bidentate bridging mode to the Cu atoms. Each Cu atom has a distorted tetragonal-bipyramidal environment, being coordinated by two N atoms of the two chelating bipy ligands and two O atoms of the doubly deprotonated oxalate anion. Pairs of perchlorate anions and water molecules are linked into rectangles by O—H⋯O bonds in which the perchlorate O atoms act as acceptors and the water molecules as donors. Methyl groups of the DMF solvent molecule are disordered over two sites with occupancies of 0.453 (7):0.547 (7), and the water molecule is half-occupied.