Synthesis, structures and Hirshfeld surface analyses of 2-hy-droxy-'-methyl-acetohydrazide and 2-hy-droxy--methyl-acetohydrazide.

The structures of the title compounds 2-hy-droxy-'-methyl-acetohydrazide, , and 2-hy-droxy--methyl-acetohydrazide, , both CHNO, as regioisomers differ in the position of the methyl group relative to the N atoms in 2-hy-droxy-acetohydrazide. In the structure of , the 2-hy-droxy-acetohydrazide core [OH-C-C(=O)-NH-NH] is almost planar and the methyl group is rotated relative to this plane. As opposed to , in the structure of all non-hydrogen atoms lie in the same plane.

Synthesis, crystal structure and Hirshfeld surface analysis of a new copper(II) complex based on diethyl 2,2'-(4-1,2,4-triazole-3,5-di-yl)di-acetate.

The title compound, bis-[μ-2,2'-(4-1,2,4-triazole-3,5-di-yl)di-acetato]-bis-[di-aqua-copper(II)] dihydrate, [Cu(CHNO)(HO)]·2HO, is a dinuclear octa-hedral Cu triazole-based complex. The central copper atoms are hexa-coordinated by two nitro-gen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxyl-ate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water mol-ecules. Two additional solvent water mol-ecules are linked to the title mol-ecule by O-H⋯N and O⋯H-O hydrogen bonds.

Crystal structure of -poly[[methanoldioxidouranium(VI)]-μ-2-[5-(2-oxidophen-yl)-1-1,2,4-triazol-3-yl]acetato-κ :'].

In the title complex, [U(CHNO)O(CHOH)] , the U cation has a typical penta-gonal-bipyramidal environment with the equatorial plane defined by one N and two O atoms of one doubly deprotonated 2-[5-(2-hy-droxy-phen-yl)-1-1,2,4-triazol-3-yl]acetic acid ligand, a carboxyl-ate O atom of the symmetry-related ligand and the O atom of the methanol mol-ecule [U-N/O 2.256 (4)-2.504 (5) Å].

Crystal structure of aqua-(nitrato-κO)dioxido{2-[3-(pyridin-2-yl-κN)-1H-1,2,4-triazol-5-yl-κN (4)]phenolato-κO}uranium(VI) aceto-nitrile monosolvate monohydrate.

In the title compound, [U(C13H9N4O)(NO3)O2(H2O)]·CH3CN·H2O, the U(VI) atom is seven-coordinated in a distorted penta-gonal-bipyramidal N2O5 manner by one tridentate triazole ligand, one monodentate nitrate anion and one water mol-ecule in the equatorial plane and by two uran-yl(VI) O atoms in the axial positions. In the crystal, the U(VI) complex mol-ecule is linked to the water and aceto-nitrile solvent mol-ecules through N-H⋯N, O-H⋯O and O-H⋯N hydrogen bonds, forming a sheet structure parallel to the bc plane. The sheets are further linked by an additional O-H⋯O hydrogen bond, forming a three-dimensional network.