Lanthanide(III) complexes with tridentate Schiff base ligand, antioxidant activity and x-ray crystal structures of the Nd(III) and Sm(III) complexes

The tridentate N4-type Schiff base was synthesized from the condensation reaction of 2-hydrazinopyridine and pyridine-2-carbaldehyde. Neodymium and Samarium complexes were isolated when the corresponding nitrate salt was added to the solution of the ligand. The isolated compounds were characterized by elemental analyses, IR study, room temperature magnetic measurements and single X-ray crystal diffraction of the two crystals. Both complexes crystallize in the monoclinic system with space group P21/c. The cell parameters of the Nd complex are a=11.0927(8) Å, b=17.9926 (13) Å, c=11.9395(9)Å and β = 115.274(5) ° while the Sm complex shows parameters cell of a = 11.0477(8) Å, b = 17.9254(13) Å, c = 11.9149(8) Å and β =115.489(5) °. The X-ray study reveals isotopic Nd/Sm binuclear structures were each metal ion is nine-coordinated in the same fashion. Both metal centers have distorted tricapped trigonal prism geometry, with the Schiff base acting as tridentate ligand. The DPPH· radical scavenging effects of the Schiff base ligand and its Ln(III) complexes were screened. The Ln(III) complexes were significantly more efficient in quenching DPPH· than the free Schiff base ligand.Keywords: Lanthanide complexes, hydrazino, antioxidant activity, X-ray structur

Synthesis, physical studies and crystal structure determination of Y(III) and Er(III) complexes of 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine

Two isotype mononuclear yttrium(III) and erbium(III) complexes, {[Y(HL)(OAc)2(H2O)2]. (H2O)∙(NO3)} (1) and {[Er(HL) (OAc)2(H2O)2].(H2O)∙(NO3)} (2), where HL is the neutral Schiff base ligand 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine, and OAc is the acetate anion, have been synthesized and characterized by physicochemical methods and single crystal X-ray determination. Both complexes crystallizes in the triclinic space group Pī with unit cell dimensions for complex of Y(III) a = 7.909 (2) Å, b = 11.718 (4) Å, c = 12.497 (3) Å,    α = 78.907 (3)°, b = 73.840 (3)°, γ = 72.074 (3)°, V = 1051.26 (6) Å3, Z = 2, R1 = 0.051 and    wR2 = 0.112 and for complex of Er(III)a = 7.913 (1) Å, b = 11.719 (2) Å, c = 12.487 (2) Å,          α = 78.832 (1)°, α = 73.674 (1)°, γ = 72.012 (1)°, V = 1049.64 (3) Å3, Z = 2, R1 = 0.028, and   wR2 = 0.062. In both complexes, the coordination polyhedra around Ln(III) atoms are best described as a distorted tricapped trigonal prism. Antioxidant activities of the ligand and its Y(III) and Er(III) complexes are studied

A Theil-like class of inequality measures, its asymptotic normality theory and applications

In this paper, we consider a coherent theory about the asymptotic representations for a family of inequality indices called Theil-Like Inequality Measures (TLIM), within a Gaussian field. The theory uses the functional empirical process approach. We provide the finite-distribution and uniform asymptotic normality of the element of the TLIM class in a unified approach rather than in a case by case one. The results are then applied to some UEMOA countries databases.Keywords: Inequality measure; Asymptotic behaviour; Asymptotic representations; functional empirical processAMS 2010 Mathematics Subject Classification: 62G05; 62G20; 62G07; 91B82; 62P2

Synthesis, physical studies and crystal structure determination of Y(III) and Er(III) complexes of 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine

Two isotype mononuclear yttrium(III) and erbium(III) complexes, {[Y(HL)(OAc)2(H2O)2]. (H2O)∙(NO3)} (1) and {[Er(HL) (OAc)2(H2O)2].(H2O)∙(NO3)} (2), where HL is the neutral Schiff base ligand 1-(pyridin-2-yl)-2-(pyridine-2-ylmethylene)hydrazine, and OAc is the acetate anion, have been synthesized and characterized by physicochemical methods and single crystal X-ray determination. Both complexes crystallizes in the triclinic space group Pī with unit cell dimensions for complex of Y(III) a = 7.909 (2) Å, b = 11.718 (4) Å, c = 12.497 (3) Å,    α = 78.907 (3)°, b = 73.840 (3)°, γ = 72.074 (3)°, V = 1051.26 (6) Å3, Z = 2, R1 = 0.051 and    wR2 = 0.112 and for complex of Er(III)a = 7.913 (1) Å, b = 11.719 (2) Å, c = 12.487 (2) Å,          α = 78.832 (1)°, α = 73.674 (1)°, γ = 72.012 (1)°, V = 1049.64 (3) Å3, Z = 2, R1 = 0.028, and   wR2 = 0.062. In both complexes, the coordination polyhedra around Ln(III) atoms are best described as a distorted tricapped trigonal prism. Antioxidant activities of the ligand and its Y(III) and Er(III) complexes are studied