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.

Crystal structure and Hirshfeld surface analysis of di-chlorido-[2-(3-cyclo-pentyl-1,2,4-triazol-5-yl-κ )pyridine-κ]palladium(II) di-methyl-formamide monosolvate.

This study presents the synthesis, characterization and Hirshfeld surface analysis of the title mononuclear complex, [PdCl(CHN)]·CHNO. The compound crystalizes in the 2/ space group of the monoclinic system. The asymmetric unit contains one neutral complex Pd(H )Cl [H is 2-(3-cyclo-pentyl-1,2,4-triazol-5-yl)pyridine] and one mol-ecule of DMF as a solvate.

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 bis-{2-[5-(3,4,5-tri-meth-oxyphenyl)-4-1,2,4-triazol-3-yl]pyridine}palladium(II) bis-(tri-fluoro-acetate) tri-fluoro-acetic acid disolvate.

The new palladium(II) complex, [Pd(CHNO)](CFCOO)·2CFCOOH, crystallizes in the triclinic space group with the asymmetric unit containing half the cation (Pd site symmetry ), one tri-fluoro-actetate anion and one co-crystallized tri-fluoro-acetic acid mol-ecule. Two neutral chelating 2-[5-(3,4,5-tri-meth-oxy-phen-yl)-4-1,2,4-triazol-3-yl]pyridine ligands coordinate to the Pd ion through the triazole-N and pyridine-N atoms in a distorted -PdN square-planar configuration [Pd-N 1.991 (2), 2.

Synthesis and crystal structure of a cadmium(II) coordination polymer based on 4,4'-(1-1,2,4-triazole-3,5-di-yl)dibenzoate.

The asymmetric unit of the title compound, -poly[[[aqua-bis-(pyridine-κ)cadmium(II)]-μ-4,4'-(1-1,2,4-triazole-3,5-di-yl)dibenzoato-κ ,':'','''] 4.5-hydrate], {[Cd(CHNO)(CHN)(HO)]·4.5HO} or {[Cd(bct)(py)(HO)]·4.

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.

Solvent- and functional-group-assisted tautomerism of 3-alkyl substituted 5-(2-pyridyl)-1,2,4-triazoles in DMSO-water.

The tautomerism of a series of 5-alkyl substituted 3-(2-pyridyl)-1,2,4-triazoles in DMSO--containing water has been investigated by H, C and N NMR spectroscopy. The populations of the three possible regioisomers in the tautomeric equilibrium (A [3-alkyl-5-(2-pyridyl)-1], B [5-alkyl-3-(2-pyridyl)-1] and C [5-alkyl-3-(2-pyridyl)-4]) were determined. Isomers A (17-40%) and B (54-79%) are the major components and their ratio is insensitive to the substitution pattern, except for the unsubstituted and the methoxymethyl substituted derivatives.

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.

An investigation of two copper(ii) complexes with a triazole derivative as a ligand: magnetic and catalytic properties.

Two new copper(ii) complexes [Cu(L)(OAc)(HO)] (1) (L = 3-methyl-5-pyridin-2-yl-1,2,4-triazole) and [CuL] (2) were prerared and thoroughly studied. The complexes are able to selectively catalyze the oxidation of styrene towards benzaldehyde and of cyclohexane to KA oil. The 2D coordination polymer 1 showed an antiferromagnetic behaviour attributed to the intrachain magnetic coupling.

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.