V.I. Pekhnyo

Formation of intermediate solid solutions in the quaternary exchange system Cu(In,Ga)(S,Se)2–2Cd(S,Se)

While record solar cells based on Cu(In,Ga)Se2 (CIGS) absorbers exhibit the highest conversion efficiencies among all thin film photovoltaic technologies, the structural nature of the electronically favourable heterojunction CIGS–CdS is still debatable. Here, we present an investigation of the phase equilibria in the full Cu(In,Ga)(S,Se)2–2Cd(S,Se) quaternary exchange system at the selected annealing temperature of 870 K in order to reveal the formation of intermediate solid solutions. There are three single phase regions in the system: the chalcopyrite α-solid solution based on Cu(In,Ga)(S,Se)2, the wurtzite β-solid solution of Cd(S,Se), and the intermediate γ-solid solution existing in a zinc blende structure. The γ-phase has a broad homogeneity range and crystallizes in the cubic space group F3m with a statistical distribution of metal atoms in the cation sub-lattice.

[Cu3(C11H12N3OS)3(C11H10N3OS)]SO4 · 3H2O, a trinuclear heteroleptic copper(II) complex with N-allyl-N′-salicylidenethiosemicarbazone and its cyclization product: Synthesis and X-ray diffraction study

Single crystals of a trinuclear copper(II) complex with N-allyl-N′-salicylidenethiosemicarbazone and its cyclization product were obtained and examined by X-ray diffraction. Prolonged keeping of the reaction mixture in aqueous ethanol at room temperature resulted in partial cyclization of the starting ligand into 2-(4-allyl-5-mercapto-4H-1,2,4-triazol-3-yl)phenol followed by coordination of both ligands to copper ions, giving a cluster-type trinuclear complex of the empirical formula C44H50N12O11S5Cu3. The crystals are monoclinic, space group P21/n, a = 14.1169(4) Å, b = 20.1006(5) Å, c = 19.6852(5) 0A, β = 107.065(2)°, Z = 4, R1 = 0.0586 (I > 4σ(I)). The structure of the complex consists of three square fragments; in each fragment, the Cu atom is coordinated in a tridentate fashion by the starting organic ligand in the thione form. The cyclization product of this ligand is coordinated through two triazole N atoms and the thiol S atom, thus extending the square environment of copper. The cluster structure of the complex is formed by the bridging bonds Cu-O-Cu between the Cu(1) and Cu(2) atoms and by the bridging bonds Cu-S-Cu between the Cu(2) and Cu(3) atoms.

Rhodium(III), palladium(II), and platinum(II) complexes with 2-(2-hydroxybenzoyl)-N-methylhydrazinecarbothioamide: Syntheses, structures, and spectral characteristics

The syntheses and spectral (IR, UV-VIS, XPS, and 1H and 13C NMR) characteristics of the rhodium(III), palladium(II), and platinum(II) complexes with 2-(2-hydroxybenzoyl)-N-methylhydrazinecarbothioamide (HBMHCTA) are described. The coordination of HBMHCTA to the central metal ion and its intraligand rearrangement in the complex formation of rhodium(III) ions are studied. The structure of the mixed-ligand complex [Pd(H2L)PPh3] is determined by X-ray diffraction analysis.

Crystal structure and magnetic properties of a new heterometallic complex of Pd(II)-Cu(II) with 1-aminoethylidene-1,1-diphosphonic acid

A heterometallic complex of Pd(II)-Cu(II) with 1-aminoethylidene-1,1-diphosphonic (AEDP) acid (C4H22CuN2O16P4Pd)n (I) is synthesized. Single crystals of compound I are obtained; its crystal structure is determined by X-ray crystallography. The crystals are orthorhombic, space group Pbcn, a = 18.366(3) Å, b = 9.7661(17) Å, c = 20.198(4) Å, V = 3622.8(11) Å3, Z = 8, dx = 2.376 g/cm3. The compound crystallizes as a coordination polymer; the square environment of Pd(II) is formed by nitrogen atoms of amino groups and oxygen atoms of phosphonic groups, while at two non-equivalent copper atoms the octahedral environment is formed by oxygen atoms of phosphonic groups and water molecules. The crystal structure of compound I is characterized by the formation of a branched network of hydrogen bonds. Based on the analysis of the temperature dependence of the magnetic susceptibility it is found that for the heterometallic complex of Pd(II)-Cu(II) with AEDP antiferromagnetic interactions between the paramagnetic centers are dominant.

Mixed complexes of palladium(II) with 1-aminoethylidene-1,1-diphosphonic acid and glycine

The complexing of palladium(II) with two biological active reagents: glycine (Gly, HA) and 1-aminoethylidene-1,1-diphosphonic acid (AEDP, H4L) at concentrations of chloride ions (0.15 mol/L) corresponding to physiological levels is studied by means of spectrophotometry, pH potentiometry, and 31P NMR spectroscopy. The formation constants for mixed complexes with compositions of [PdH2LA]− (logβ = 43.7) and [PdHLA]2− (logβ = 39.05) are determined. The both ligands are found to be coordinated to palladium(II) in a bidentant-cyclic manner: through amine nitrogen and the oxygen atom of the carboxyl group (in the case of Gly), or through the phosphonic group (in the case of AEDP). A diagram of the distribution of equilibrium concentrations of the complexes depending on pH is calculated for the system K2[PdCl4]: Gly: AEDP = 1: 1: 1. It is demonstrated that there are complexes with compositions of [PdHLA]2−, [PdA2], and [Pd(HL)2]4− in solutions with

Synthesis, structural and spectral characterization of Zn(II) complexes, derived from thiourea and thiosemicarbazide

C_{Cl^ - } = 0.15 mol/L

New dodecanuclear phenylphosphonate-bridged Co(II) complexes

and pH 6–7.

Novel Pd(II) coordination compounds involving 2-[(2-hydroxyphenyl)methylene]hydrazine-N-(2-propenyl)-carbothioamide as a ligand or pro-ligand: Synthesis, crystal structures and analytical application

Complexation in the systems K2PdCl4-3-amino-1-hydroxypropane-1,1-diyldiphosphonic acid (AHPDP) and K2PdCl4-1-aminoethane-1,1-diyldiphosphonic acid (AEDP) was studied using pH-potentiometry, spectrophotometry, and 31P NMR spectroscopy. It was found that AHPDP in equimolar complexes is coordinated by Pd(II) in a bidentate fashion through two phosphonate O atoms forming a six-membered chelate [O,O]-ring, while AEDP is coordinated through the N atom and one phosphonate O atom forming a five-membered chelate [N,O]-ring. In 1: 2 complexes of Pd(II) with AEDP, the second AEDP molecule is coordinated by Pd(II) in a similar way to form a second five-membered [N,O]-ring. The latter complexes show cis-trans and syn-anti isomerism. The structural characteristics of the corresponding isomers were calculated at the DFT level of theory and their stabilities were compared.