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.

Synthesis and crystal structure of ,-di-methyl-ethane-dihydrazide.

The title compound, , -di-methyl-ethane-dihydrazide, CHNO, was obtained by the methyl-ation of oxalyl dihydrazide protected with phthalimide. The mol-ecule is essentially non-planar with a dihedral angle between the two planar hydrazide fragments of 86.5 (2)°.

Crystal structure and Hirshfeld-surface analysis of di-aqua-bis-(5-methyl-1-1,2,4-triazole-3-carboxyl-ato)copper(II).

The title compound, [Cu(H)(HO)] or [Cu(CHNO)(HO)], is a mononuclear octa-hedral Cu complex based on 5-methyl-1-1,2,4-triazole-3-carb-oxy-lic acid (H ). [Cu(H)(HO)] was synthesized by reaction of H with copper(II) nitrate hexa-hydrate (2:1 stoichiometric ratio) in water under ambient conditions to produce clear light-blue crystals. The central Cu atom exhibits an NO coordination environment in an elongated octa-hedral geometry provided by two bidentate H anions in the equatorial plane and two water mol-ecules in the axial positions.

Synthesis and crystal structure of a new copper(II) complex based on 5-ethyl-3-(pyridin-2-yl)-1,2,4-triazole.

The title compound, bis-[μ-3-ethyl-5-(pyridin-2-yl)-1-1,2,4-triazol-1-ido]bis[acetato-(di-methyl-formamide)-copper(II)], [Cu(CHN)(CHO)(CHNO)] or [Cu( )(OAc)(dmf)], is a triazolate complex, which contains two 3-(2-pyrid-yl)-5-ethyl-triazolates ( ) in bidentate-bridged coordination modes. Both copper atoms are involved in the formation of a planar six-membered metallocycle Cu-[N-N]-Cu. The inversion center of the complex is located at the mid-point of the Cu⋯Cu vector.

Synthesis and crystal structure of hydrated μ-oxa-lato-bis-{bis-[3-methyl-5-(pyridin-2-yl)-1-1,2,4-triazole]iron(II)} bis-(toluene-sulfonate) 2.75-hydrate.

In the title compound [Fe(CO)(CHN)](CHCHSO)·2.75HO, the two Fe ions have a highly distorted octa-hedral FeNO environment formed by two bidentate triazole-based chelating ligands and a bis-bidentate oxalate bridging anion that connects the metal ions. Stabilization within the crystal structure is provided a system of O-H⋯O and N-H⋯O hydrogen bonding, which determines the formation of a two-dimensional architecture along the axis direction.

Expanding the chemical space of 3(5)-functionalized 1,2,4-triazoles.

Unlabelled: An efficient approach to the gram-scale synthesis of 3(5)-substituted, 1,3- and 1,5-disubstituted 1,2,4-triazole-derived building blocks is described. The key synthetic precursors - 1,2,4-triazole-3(5)-carboxylates (20 examples, 35-89% yield) were prepared from readily available acyl hydrazides and ethyl 2-ethoxy-2-iminoacetate hydrochloride. Further transformations were performed following the convergent synthetic strategy and allowed the preparation of 1,3- and 1,5-disubstituted 1,2,4-triazole-derived esters (16 examples, 25-75% yield), 3(5)-substituted, 1,3- and 1,5-disubstituted carboxylate salts (18 examples, 78-93% yield), amides (5 examples, 82-93% yield), nitriles (5 examples, 30-85% yield), hydrazides (6 examples, 84-89% yield), and hydroxamic acids (3 examples, 73-78% yield).

Synthesis of α-substituted 2-(1-1,2,4-triazol-3-yl)acetates and 5-amino-2,4-dihydro-3-pyrazol-3-ones the Pinner strategy.

A series of 2-(1-1,2,4-triazol-3-yl)acetates, as well as 4-mono- and 4,4-disubstituted 5-amino-2,4-dihydro-3-pyrazol-3-ones (including spirocyclic derivatives) have been synthesized using the Pinner reaction strategy. α-Mono- and α,α-disubstituted ethyl cyanoacetates were converted into the corresponding carboxyimidate salts that served as the key intermediates. Their further reaction with formylhydrazide or hydrazine hydrate provided triazolylacetates or aminopyrazolones (including spirocyclic derivatives), depending on the structure of the starting Pinner salt and the nature of the nucleophile.

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.

Bis(methanol-κO)dioxido[3,3'-(1H-1,2,4-triazole-3,5-diyl)diphenolato-κ3O,N4,O']uranium(VI) methanol monosolvate.

The structure of the title compound, [U(C(14)H(9)N(3)O(2))O(2)(CH(3)OH)(2)]·CH(3)OH, is the first to be reported for an actinide complex including triazole ligands. The U(VI) atom exhibits a pentagonal-bipyramidal NO(6) coordination environment, involving two axial oxide ligands [U=O = 1.766 (3) and 1.