Synthesis, Characterization and Crystal Structure of Bis[1-methoxy-2,2,2-tris-(pyrazol-1-yl-κN2)ethane]-copper(II) Bis-perchlorate

Abstract

Bis[1-methoxy-2,2,2-tris-(pyrazol-1-yl-κN 2 )ethane]-copper(II) bis-perchlorate (2) was synthesized by reacting of pyrazole based tripodal scorpionate ligand 1-methoxy-2,2,2-tris(pyrazol-1-yl)ethane (1) with copper(II) perchlorate hexahydrate in methanol, acetonitrile and water mixture as solvent. Slow evaporation of the filtered reaction mixture in air produced blue color block crystals suitable for single crystal X-ray diffraction study of the title complex. Compound 2 crystallizes in the monoclinic space group P2 1 /n with unit cell parameters, a = 8.1269(1) Ả, b = 21.8348(2)Ả, c = 9.1522(1) Å, α = γ = 90º, β = 99.7611(4)º. The structure of the compound was characterized by IR Spectroscopy, elemental analysis and single crystal X-ray diffraction analysis.

Synthesis, Characterization and Crystal Structure of Bis[1-methoxy-2,2,2-tris-(pyrazol-1-yl-κN2) ethane]-cobalt (II) bis-perchlorate

“…The average nitrogen-cobalt (II)-nitrogen angle between adjacent pyrazole-ring-coordinated nitrogen atoms is 83.6° for the six acute angles and 96.4° for the six obtuse angles. This is very similar to what we observed in previously published complex with copper (II) (Lyubartseva et al, 2016), where the average nitrogen-copper (II)-nitrogen angle between adjacent pyrazole-ring-coordinated nitrogen atoms was 83.7° for the six acute angles and 96.3° for the six obtuse angles. In case of two new compounds with nickel (II) metal, the average nitrogen-nickel (II)-nitrogen angle between adjacent pyrazole-ring-coordinated nitrogen atoms were 84.8°and 85.1° correspondingly for the six acute angles, and 95.2° and 94.9° correspondingly for the six obtuse angles (Lyubartseva et al, 2013a;Lyubartseva et al, 2013b).…”

“…In the crystal, the cobalt (II) ion is coordinated by six nitrogen atoms from two tridentate ligand molecules of ligand 1-methoxy-2,2,2-tris(pyrazol-1-yl) ethane ( 1) with an average cobalt (II)-nitrogen distance of 2.1046 Å. This is a shorter distance compared to the one in the copper (II) complex we published previously (Lyubartseva et al, 2016), where the average copper (II)-nitrogen distance was 2.1224 Å. However, this is a longer distance compared to the analogous distances in two nickel (II) complexes, which we characterized previously, where the average nickel (II)-nitrogen distance were 2.062Å and 2.065 Å correspondingly (Lyubartseva et al, 2013a;Lyubartseva et al, 2013b).…”

“…Derivatives of pyrazoles have been studied extensively for useful biological effectiveness due to their antiinflammatory, anti-diabetic, anesthetic and analgesic properties (Sarojini et al, 2010;Padhy et al, 2017). In addition, structurally, pyrazole based tridentate ligands have a tendency to bind transition metals in a scorpionate fashion which produces significant number of novel coordination compounds (Lyubartseva & Parkin, 2009;Lyubartseva & Parkin, 2010a;Lyubartseva & Parkin, 2010b;Lyubartseva et al, 2011;Lyubartseva et al, 2013a;Lyubartseva et al, 2013b;Lyubartseva et al, 2014;Lyubartseva et al, 2016).…”