Synthesis and structural characterization of copper(II) complexes with a tetradentate semicarbazone ligand derived from 2,5-hexadione

Abstract

Four Cu(II) complexes [CuLH 2 O](ClO 4 ) 2 , 1; [CuLCl]Cl.H 2 O, 2; [CuLBr] 2 (Cu 3 Br 5 ), 3; and [CuLH 2 O](NO 3 ) 2 , 4;where L = tetradentate semicarbazone ligand, have been synthesized and characterized by elemental analysis, FT-IR and UV-Vis. The structures of compounds 1 and 3 have been determined by single-crystal X-ray diffraction analyses. In mononuclear 1, the semicarbazone, L acts as a tetradentate neutral ligand and a water molecule also coordinates to the Cu atom. There are two independent [CuL(H 2 O)] 2+ cations and four perchlorate anions in the crystallographic asymmetric unit. One of the cations has a weak interaction between its Cu atom and a O atom of an adjacent perchlorate anion. The structure of 3 contains two independent [CuLBr] + cations and a (Cu 3 Br 5 ) 2− anion. The coordination geometry around the cation's Cu(II) ion is five-coordinated square pyramidal, with L acting as a tetradentate neutral ligand and with a Br at the apical position. The Cu 3 Br 5 2− anions link to one another to form an infinite one-dimensional (Cu 3 Br 5 2− ) n chain. Furthermore, the Hirshfeld surface analyses and the 2D fingerprint plot have been discussed.

Nickel(II) Complex with a Flexidentate Ligand Derived from Acetohydrazide: Synthesis, Structural Characterization and Hirshfeld Surface Analysis

“…The Hirshfeld surface analyses and the fingerprint plots provide some useful quantitative information about the strength and role of the intermolecular contacts, and to estimate their importance in the in the crystal packing stability. 1,26,33,34 In Fig. 3 The mean planes of the pyrazole and aromatic rings in complex 1 are almost perpendicular.…”

“…The complexation of transition metal ions with multidentate Schiff base ligands has been studied extensively as their structures can be divers and they can have versatile properties. [1][2][3] The hydrazone ligands which are formed by condensation reactions between hydrazide derivatives and relevant aldehyde or ketones, are a signification class of such multidentate ligands. Metal complexes with these ligands can have a wide range of structures with significant variations in geometry.…”