Di-μ3-chlorido-1:2:3κ3Cl;2:3:4κ3Cl-di-μ2-chlorido-1:2κ2Cl;3:4κ2Cl-tetra­kis­[(4-amino-1,5-dimethyl-2-phenyl-2,3-di­hydro-1H-pyrazol-3-one-κ2N4,O)chlorido­cadmium(II)] 1.7-hydrate: a new six-coordinate geometry index, τ6

Abstract

A new tetra­nuclear cadmium(II) com­plex of 4-amino­anti­pyrine and chloride ions was synthesized using methanol as solvent. The com­plex possesses inversion symmetry with two independent Cd²⁺ ions that have different coordination spheres, one fivefold and the other sixfold. A new geometry index, τ₆, is propossed to qu­anti­tatively describe the geometry of a sixfold coordinated atom.

The title centrosymmetric tetra­nuclear cadmium(II) com­plex of 4-amino­anti­pyrine and chloride ions, [Cd₄Cl₈(C₁₁H₁₃N₃O)₄]·1.7H₂O, was synthesized using methanol as solvent. The two independent Cd²⁺ ions in the asymmetric unit have different geometries; the outer Cd atoms have fivefold CdONCl₃ coordination spheres, while the inner Cd atoms have sixfold CdONCl₄ coordination spheres. The com­plex is consolidated by intra­molecular N—H⋯O and N—H⋯Cl hy­dro­gen bonds. In the crystal, a combination of N—H⋯Cl and O_w—H⋯Cl (w = water) hy­dro­gen bonds link the com­ponents to form chains propagating along the a-axis direction. The chains are crosslinked by C—H⋯Cl and C—H⋯O hy­dro­gen bonds to form a three-dimensional structure. A new geometry index, τ₆, is proposed to qu­anti­tatively estimate the geometry of a sixfold coordinated atom.