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

The title compound, [Cu(HL)2(H2O)2] or [Cu(C4H4N3O2)2(H2O)2], is a mononuclear octa-hedral CuII complex based on 5-methyl-1H-1,2,4-triazole-3-carb-oxy-lic acid (H2 L). [Cu(HL)2(H2O)2] was synthesized by reaction of H2 L 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 N2O4 coordination environment in an elongated octa-hedral geometry provided by two bidentate HL - anions in the equatorial plane and two water mol-ecules in the axial positions. Hirshfeld surface analysis revealed that the most important contributions to the surface contacts are from H⋯O/O⋯H (33.1%), H⋯H (29.5%) and H⋯N/N⋯H (19.3%) inter-actions.

Carbon dioxide capture from air leading to bis-[N-(5-methyl-1H-pyrazol-3-yl-κN2)carbamato-κO]copper(II) tetra-hydrate.

A mononuclear square-planar CuII complex of (5-methyl-1H-pyrazol-3-yl)carbamate, [Cu(C5H6N3O2)2]·4H2O, was synthesized using a one-pot reaction from 5-methyl-3-pyrazolamine and copper(II) acetate in water under ambient conditions. The adsorption of carbon dioxide from air was facilitated by the addition of di-ethano-lamine to the reaction mixture. While di-ethano-lamine is not a component of the final product, it plays a pivotal role in the reaction by creating an alkaline environment, thereby enabling the adsorption of atmos-pheric carbon dioxide. The central copper(II) atom is in an (N2O2) square-planar coordination environment formed by two N atoms and two O atoms of two equivalent (5-methyl-1H-pyrazol-3-yl)carbamate ligands. Additionally, there are co-crystallized water mol-ecules within the crystal structure of this compound. These co-crystallized water mol-ecules are linked to the CuII mononuclear complex by O-H⋯O hydrogen bonds. According to Hirshfeld surface analysis, the most frequently observed weak inter-molecular inter-actions are H⋯O/O⋯H (33.6%), H⋯C/C⋯H (11.3%) and H⋯N/N⋯H (9.0%) contacts.

Crystal structure of polymeric bis-(3-amino-1H-pyrazole)-cadmium dibromide.

The reaction of cadmium bromide tetra-hydrate with 3-amino-pyrazole (3-apz) in ethano-lic solution leads to tautomerization of the ligand and the formation of crystals of the title compound, catena-poly[[di-bromido-cadmium(II)]-bis-(µ-3-amino-1H-pyrazole)-κ2 N 3:N 2;κ2 N 2:N 3], [CdBr2(C3H5N3)2]n or [CdBr2(3-apz)2]n. Its asymmetric unit consists of a half of a Cd2+ cation, a bromide anion and a 3-apz mol-ecule. The Cd2+ cations are coordinated by two bromide anions and two 3-apz ligands, generating trans-CdN4Br2 octa-hedra, which are linked into chains by pairs of the bridging ligands. In the crystal, the ligand mol-ecules and bromide anions of neighboring chains are linked through inter-chain hydrogen bonds into a two-dimensional network. The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative qu-anti-tative contributions of the weak inter-molecular contacts.

catena-Poly[[tetra-kis-(3,5-dimethyl-1H-pyrazole-κN 2)copper(II)]-µ2-sulfato-κ2 O:O']: crystal structure and Hirshfeld surface analysis of a CuII coordination polymer.

The title coordination polymer, [Cu(SO4)(C5H8N2)4] n , was synthesized using a one-pot reaction of copper powder, anhydrous copper(II) sulfate and 3,5-dimethyl-1H-pyrazole (Hdmpz) in aceto-nitrile under ambient conditions. The asymmetric unit can be described as a chain consisting of four [Cu(SO4)(Hdmpz)4] formula units that are connected to each other by a µ2-sulfato-bridged ligand. The octa-hedral coordination geometry (O2N4) of all copper atoms is realized by coordination of four pyrazole ligands and two sulfate ligands. Four pyridine-like N atoms of the pyrazole ligands occupy the equatorial positions, while two oxygen atoms of two sulfate ligands are in axial positions. As a result of the sulfate ligand rotation, there is a pairwise alternation of terminal O atoms (which are not involved in coordination to the copper atom) of the SO4 tetra-hedra. The Cu⋯Cu distances within one asymmetric unit are in the range 7.0842 (12)-7.1554 (12) Å. The crystal structure is built up from polymeric chains packed in a parallel manner along the b-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯H (74.7%), H⋯O/O⋯H (14.8%) and H⋯C/C⋯H (8.2%) inter-actions.

Crystal structure and Hirshfeld surface analysis of di-µ-chlorido-bis-[(aceto-nitrile-κN)chlorido-(ethyl 5-methyl-1H-pyrazole-3-carboxyl-ate-κ2 N 2,O)copper(II)].

The title compound, [Cu2Cl4(C5H10N2O2)2(CH3CN)2] or [Cu2(µ2-Cl)2(CH3-Pz-COOCH2CH3)2Cl2(CH3CN)2], was synthesized using a one-pot reaction of copper powder, copper(II) chloride dihydrate and ethyl 5-methyl-1H-pyrazole-3-carboxyl-ate (CH3-Pz-COOCH2CH3) in aceto-nitrile under ambient conditions. This complex consists of discrete binuclear mol-ecules with a {Cu2(µ2-Cl)2} core, in which the Cu⋯Cu distance is 3.8002 (7) Å. The pyrazole-based ligands are bidentate coordinated, leading to the formation of two five-membered chelate rings. The coordination geometry of both copper atoms (ON2Cl3) can be described as distorted octa-hedral on account of the aceto-nitrile coordination. A Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯H (40%), H⋯Cl/Cl⋯H (24.3%), H⋯O/O⋯H (11.8%), H⋯C/C⋯H (9.2%) and H⋯N/N⋯H (8.3%) inter-actions.

Crystal structure of bis-{µ-2-[bis-(2-hy-droxy-eth-yl)amino]-ethano-lato}bis-(µ-3,5-di-methyl-pyrazolato)tricopper(II) dibromide sesquihydrate.

In the title bicyclic trinuclear pyrazolate amino-alcohol complex, [Cu3(C5H7N2)2(C6H14NO3)2]Br2·1.5H2O, the central Cu atom lies on a center of symmetry and is involved in the formation of two five-membered rings. It has a coordination number of 4, is in a distorted tetra-hedral environment and is connected by the bridging oxygen atoms of the deprotonated OH groups of different amino-alcohol groups, and by the N atoms of deprotonated di-methyl-pyrazole ligands. The peripheral Cu atom is in a trigonal-bipyramidal coordination environment formed by the nitro-gen atom of the deprotonated bridging di-methyl-pyrazole unit, the bridging oxygen atom of the deprotonated OH group, two oxygen atoms of the protonated hy-droxy groups and the nitro-gen atom of tri-ethano-lamine. One of the C atoms and the Br- anion were found to be disordered over two positions with occupancy factors of 0.808 (9):0.192 (9) and 0.922 (3):0.078 (3), respectively.

Crystal structure of di-chlorido-1κCl,2κCl-(µ2-3,5-dimethyl-1H-pyrazolato-1κN 2:2κN 1)(3,5-dimethyl-1H-pyrazole-2κN 2){µ-2-[(2-hy-droxy-eth-yl)amino-1κ2 N,O]ethano-lato-1:2κ2 O:O}dicopper(II).

The title compound, [Cu2(C5H7N2)(C4H10NO2)Cl2(C5H8N2)], is a pyrazolate amino-alcohol complex which contains two di-methyl-pyrazole mol-ecules in monodentate and bidentate-bridged coordination modes and a monodeproton-ated di-ethano-lamine mol-ecule. Both copper atoms are involved in the formation of non-planar five-membered chelate rings. One Cu atom is in a distorted tetra-hedral environment formed by the pyridine nitro-gen atom of the protonated di-methyl-pyrazole mol-ecule, the N atom of the deprotonated bridged di-methyl-pyrazole, the Cl atom and the bridged O atom of the monodeprotonated di-ethano-lamine. The second Cu atom has an inter-mediate environment between trigonal bipyramidal and square pyramidal, formed by the N atom of the deprotonated bridged di-methyl-pyrazole, the Cl atom and the N atom of the amino-alcohol, and two O atoms of the deprotonated and protonated OH groups. In the crystal, N-H⋯Cl hydrogen bonds link the molecules into anti-symmetric chains running along the a-axis direction. Adjacent chains are connected by O-H⋯O hydrogen bonds involving the hydroxyl group as donor.