Complexation du 2-[(5-méthylpyrazolyl)méthyle]benzimidazole par les chlorures de cuivre et de cadmium

Abstract

The structures of dichloro[2-[(5-methyl-1H-pyrazol-3-yl-kappaN(2))methyl]-1H-1,3-benzimidazole-kappaN(3)]copper(II), [CuCl(2)(C(12)H(12)N(4))], and di-mu-chloro-bis(chloro[2-[(5-methyl-1H-pyrazol-3-yl-kappaN(2))methyl]-1H-1,3-benzimidazole-kappaN(3)]cadmium(II)), [Cd(2)Cl(4)(C(12)H(12)N(4))(2)], show that these compounds have the structural formula [ML(Cl)(2)](n), where L is 2-[(5-methylpyrazolyl)methyl]benzimidazole. When M is copper, the complex is a monomer (n = 1), with a tetrahedral coordination for the Cu atom. When M is cadmium (n = 2), the complex lies about an inversion centre giving rise to a centrosymmetric dimer in which the Cd atoms are bridged by two chloride ions and are pentacoordinated.

Heteroscorpionate-Based Co2+, Zn2+, and Cu2+ Complexes: Coordination Behavior, Aerobic Oxidation, and Hydrogen Sulfide Detection

“…Hence, the geometry at the copper is intermediate between square planar and tetrahedral and is better described as distorted tetrahedral because the twist angle is much closer to the 90° angle expected for a tetrahedron as compared to the 180° angle for the square planar description. Distortion from planarity is unusual for Cu(II) complexes, but more common for complexes with large steric hindrance. − Here, the distorted coordination geometry observed in 3 could be attributed to the steric repulsion between the coordinated Cl and the methyl groups of the pyrazoles. The other structural parameters are in good agreement with those observed in CuCl 2 complexes exhibiting distorted pseudotetrahedral geometry. − …”

“…Distortion from planarity is unusual for Cu(II) complexes, but more common for complexes with large steric hindrance. [34][35][36][37][38][39][40][41][42][43] Here, the distorted coordination geometry observed in 3 could be attributed to the steric repulsion between the coordinated Cl and the methyl groups of the pyrazoles. The other structural parameters are in good agreement with those observed in CuCl 2 complexes 17 exhibiting distorted pseudotetrahedral geometry.…”

“…The other structural parameters are in good agreement with those observed in CuCl 2 complexes 17 exhibiting distorted pseudotetrahedral geometry. [34][35][36][37][38][39][40][41][42][43] Table 3. Selected Geometrical Parameters (A ˚and degrees) for Compound (4) a The reaction of CoCl 2 3 6H 2 O, ZnCl 2 , and CuCl 2 3 2H 2 O with the less sterically hindered L2-H ligand led to different products (Scheme 2).…”