Effect of an additional functional group on the structure and properties of copper(II) and nickel(II) o-iminoquinone complexes
- 70 Downloads
Nickel(II) and copper(II) bis-o-iminosemiquinone complexes were synthesized based on 4,6-di-tert-butyl-N-(2-methoxyphenyl)-o-aminophenol (Ni(imSQOMe)2 (1) and Cu(imSQOMe)2 (2)), and methyl 2-(3,5-di-tert-butyl-2-hydroxyphenylamino)benzoate (Ni(imSQC(O)OMe)2 (3) and Cu(imSQC(O)OMe)2 (4)). The molecular structures of these complexes were established by X-ray diffraction. The metal atoms in complexes 1, 3, and 4 are in square-planar coordination, whereas the square-planar coordination of the copper atom in complex 2 is substantially distorted, as evidenced by the angle between the planes of the o-iminosemiquinone ligands (22.7°). Complexes 1 and 3 are diamagnetic. The absence of line broadening in the 1H NMR spectra of these compounds at 293 K attests to the singlet spin state. The temperature dependences of the effective magnetic moment for complexes 2 and 4 are indicative of their doublet ground spin state (S = 1/2) and the thermally populated quartet state (S = 3/2). The presence of an unpaired electron on the metal center in the ground spin state for compounds 2 and 4 was confirmed by EPR spectroscopy.
Key wordsredox-active ligand o-iminobenzosemiquinolate nickel(II) copper(II) magnetic properties X-ray diffraction study electron paramagnetic resonance
Unable to display preview. Download preview PDF.
- 16.A. Mukherjee, R. Mukherjee, Ind. J. Chem., Sect. A, 2011, 50, 484.Google Scholar
- 21.S. S. Batsanov, Russ. J. Inorg. Chem. (Engl. Transl.), 1991, 36, 1694 [Zh. Neorg. Khim., 1991, 36, 3015].Google Scholar
- 22.S. Mukherjee, E. Rentschler, T. Weyhermuller, K. Wieghardt, P. Chaudhuri, Chem. Commun., 2003, 1828.Google Scholar
- 26.C. Reichardt, Solvents and Solvent Effects in Organic Chemistry, VCH, Weinheim, 1988, 534 p.Google Scholar
- 27.A. J. Gordon, R. A. Ford, The Chemist´s Companion, Wiley Intersci. Publ., New York, 1972, 537 p.Google Scholar
- 30.G. M. Sheldrick, SHELXTL v. 6.12, Structure Determination Software Suite, Bruker AXS, Madison, Wisconsin, USA, 2000.Google Scholar
- 31.SCALE3 ABSPACK: Empirical Absorption Correction, CrysAlis Pro — Software Package, Agilent Technologies, 2012.Google Scholar
- 32.G. M. Sheldrick, SADABS v.2.01, Bruker/Siemens Area Detector Absorption Correction Program, Bruker AXS, Madison, Wisconsin, USA, 1998.Google Scholar