Syntheses and Crystal Structures of Metal Complexes with 2,2′-Biimidazole-like Ligand and Chloride: Investigation of X−H···Cl (X = N, O, and C) Hydrogen Bonding and Cl−π (imidazolyl) Interactions

Abstract

Six complexes containing the 2,2′-biimidazole-like ligand and chloride, namely, trans-[Ni(H 2 biim) 2 (H 2 O) 2 ]Cl 2 (1), trans-[Co 1.5 (H 2 biim) 3 (Hand [Zn 2 (Hbbim) 2 (bbim) 0.5 Cl] (6) (where H 2 biim ) 2,2′-biimidazole, H 2 bbim ) 2,2′-bibenzimidazole) have been synthesized by the reactions of the H 2 biim or H 2 bbim ligand with the metal chloride salts. The structures of the complexes were determined by singlecrystal X-ray diffraction analyses, and the results revealed that the distances of N • • • Cl varied from 3.10 to 3.29 Å and the angles of N-H • • • Cl varied from 148 to 169°, O • • • Cl varied from 3.09 to 3.16 Å, O-H • • • Cl varied from 151 to 178°, C • • • Cl varied from 3.49 to 3.69 Å, and C-H • • • Cl varied from 122 to 167°.The chloride may act as a multi hydrogen bonded acceptor varying from 3 to 6, resulting in an important collective contribution to cohesion. The data observed in this study seem to suggest that a variety of X-H • • • Cl (X ) N, O, and C) synthons identified here play a crucial role in the formation and further stabilization of supramolecular architecture, for instance, to link the discrete (0D) or low-dimensional (1D) entities into high-dimensional frameworks. In particular, the coplanar [(H 2 O) 2 Cl 2 ] 2guests are encapsulated in the cavities formed by four [Co(H 2 bbim) 3 ] 2+ cations and stabilized via accepting 6-fold hydrogen bonds from three H 2 bbim ligands in 5. The distance between the chloride anion and the imidazolyl ring (Cl • • • centroid, 3.30 Å and 80°) demonstrates the possible existence of Cl • • • π (imidazolyl) charge-assisted interactions because the coordination of a positively charged Co(II) ion greatly enhances the electron-deficient character of the imidazolyl ring and provides sufficient polarization to produce an anion-π charge-assisted interaction.

Syntheses, structures and properties of a new compound of the type [Zn(4,4′-dmo-2,2′-bpy)2(CH3COO)]2[Zn(SCN)4]·H2O with zinc in two cationic and one anionic complexes

“…The four terminal N-coordinated isothiocyanato groups in the [Zn(NCS) 4 ] 2− complex anion form a distorted coordination tetrahedron around Zn3, with bond parameters in the following ranges: Zn3-N: 1.937 (7) • . The S-C average distance of 1.595(2)Å and C-N average distance of 1.165(3)Å are in accordance with the values observed in other thiocyanato-containing metal complexes [18,19]. The shortest Zn···Zn separation is 6.372(2)Å.…”

Structural, Electrochemical, DNA Binding and Cleavage Properties of Nickel(II) Complex [Ni(H2biim)2(H2O)2]2+of 2,2'-Biimidazole

“…[20][21][22] Even though there are some reported complexes of biimidazole already available the nickel complex with perchlorate ion is not yet reported. The crystal structure obtained in this paper has dimeric structure and differs from those reported earlier with Crystal structure show extensive intermolecular noncovalent interactions involving the axial aqua ligand, lattice anion and the biimidazole.…”

Crystal structure of bis(biimidazole-k2N,N')- bis(isothiocyanato-kN)cobalt(II)-dimethylsulfoxide (1:2), Co(C6H6N4)2(NCS)2 · 2C2H6SO

“…Metal-organic supramolecular compounds have received much attention due to their structural diversities and potential applications as new materials [1][2][3][4][5]. The consideration and utilization of the coordination bonds, intermolecular hydrogen bonds and p-p packing interactions helps to control the molecular arrangement.…”