Synthesis, characterization and crystal structure of [Cu2(LH)2]•(ClO4)2. Influence of the weak Cu•••O(perchlorate) interaction on the structure of Cu2N2O2 metallocycle

Abstract

The diimine-dioxime ligand, 3,3′-(1,4-butanediyl-dinitrilo)bis-2--pentanone, 2,2′-dioxime (LH 2 ), containing a N 4 donor set was prepared by the Schiff base condensation of 2-hydroxyimino-3-pentanone and 1,4-diaminobutane in two ways: in a protic and in an aprotic solvent. A higher yield of the (LH 2 ) imine was obtained when the synthesis was performed using a protic solvent (C 2 H 5 OH) instead of aprotic benzene (78 and 30 %, respectively). The Cu(II) metal complex of diimine-dioxime was synthesized in CH 3 OH from the perchlorate salt of LH 2 in a 1:1 mole ratio. The isolated complex was characterized by the elemental analysis, IR spectroscopy and cyclic voltammetry. The structure of [Cu 2 (LH) 2 ](ClO 4 ) 2 was determined by single-crystal X-ray diffraction analysis. Comparison with structurally related diimine-dioxime Cu(II) complexes revealed the influence of a weak Cu … O(perchlorate) interaction on the geometry of the metallocycle.

Co(III), Ni(II) and Cu(II) complexes with a tetradentate Schiff base ligand: synthesis, characterization, electrochemical behavior, binding assessment andin vitrocytotoxicity

“…LTQ Orbitrap XL (MS/ 250A) Mass Spectrometer (Heated ESI) was used for recording mass spectra in a positive mode in acetonitrile (1) and methanol (2). The synthesis and characterization of corresponding Cu complex, [Cu 2 (LH) 2 ]•(ClO 4 ) 2 (3) was recently reported [35] and 3 was further investigated alongside with 1 and 2.…”

“…Synthesis and single-crystal X-ray diffraction analysis of [Cu 2 (LH) 2 ](ClO 4 ) 2 (3) were previously reported by our group following identical synthetic route of 2 [35]. Yield 68%; mp: >225 °C explosive.…”