title: Spectroscopic and electron-transfer reactivity studies of bulky bis(N-cycloalkyl-3,5-tBu2-salicylaldiminato)copper(II) complexes: generation of uncoordinated and coordinated phenoxyl radicals.
abstract: This work summarizes the results of our studies on the spectral, magnetic, electrochemical and chemical redox properties of N-cycloalkyl-3,5-(t)Bu(2)-salicylaldimine ligands [cycloalkyl=cyclo-C(5)H(9)(HL(1)), cyclo-C(6)H(11) (HL(2)), cyclo-C(7)H(13) (HL(3)), cyclo-C(8)H(15) (HL(4)), 1-adamantyl (HL(5)), 2-adamantyl (HL(6))] and their copper(II) complexes (1-6). The compounds have been characterized by IR, (1)H NMR, UV-vis, EPR spectroscopy, electrochemical and magnetic susceptibility measurements. The geometry of 1-6, according to their EPR (g(II) and g(II)/A(II)) and visible spectral data, exhibit a significant amount distortion from slightly distorted square-planar to pseudo-tetrahedral. The cyclic voltammetric studies of 1-6 reveal that as the extent of the tetrahedral distortion of Cu(II) center increases on going from 1 to 5, the values of Cu(II)/Cu(I) potentials became more negative. The compounds have been oxidized electrochemically and chemically and the generated relatively stable uncoordinated phenoxyl [HL(x)](*+) and coordinated Cu(II)-phenoxyl radical [1-6](*+) species have been characterized by UV/vis and EPR spectroscopy.
authors.affiliation: Department of Chemistry, Harran University, Osmanbey, 63300 Sanliurfa, Turkey. vkasumov@harran.edu.tr
authors.forename: Veli T
authors.initials: VT
authors.lastname: Kasumov
authors.forename: Fevzi
authors.initials: F
authors.lastname: Köksal
authors.forename: Ayşegül
authors.initials: A
authors.lastname: Kutluay
mesh_terms: D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D009682:Magnetic Resonance Spectroscopy; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009942:Organometallic Compounds; D010636:Phenols; C042329:phenoxy radical; D003300:Copper