The electronic properties and stereochemistry of mono-nuclear complexes of the copper(II) ion

EPR and optical absorption spectral studies on voglite mineral

“…Based on these assignments, the octahedral field (Dq) and tetragonal field (Dt and Ds) parameters, evaluated using the formulae given in the literature, are given in Table 1. The same sign obtained for Dq and Dt indicates an axial elongation in the tetragonal field and also confirms the ground state [36,37]. Since, two copper ions are present, one will form one set and the other form another set.…”

An expanded cavity hexaamine cage for copper(ii)

“…2 EPR spectroscopy has been traditionally the most effective tool for elucidating the true ground state electronic configuration of mononuclear Cu(II) complexes. 17 Briefly, in the d 9 electronic configuration of a six-coordinate Cu(II) complex, the single unpaired electron will reside in either the d x 2 −y 2 orbital for tetragonally elongated complexes (more common), or the d z 2 orbital for a tetragonally compressed geometry. For magnetically dilute systems (no exchange coupling) exhibiting pseudo-axial symmetry, a d x 2 −y 2 ground state will give rise to an EPR spectrum with g (g z ) > g ⊥ .…”

“…The ordering of the g values is reversed for tetragonally compressed structures and a so-called 'inverse' EPR spectrum is found (g < g ⊥ ). 3, 17 The frozen solution EPR spectrum of [Cu(fac-Me 5 -tricosane-N 6 )] 2+ (DMF-H 2 O 1 : 2, 40 K) is shown in Fig. 3.…”

Copper(II) complexes derived from di-2-pyridyl ketone-N4-phenyl-3-semicarbazone: Synthesis and spectral studies

“…The geometric parameter G is calculated as G = g || − 2.0023/g ⊥ − 2.0023 for axial spectra and it is a measure of exchange interaction between copper centers in the polycrystalline compound. If G > 4.4, exchange interaction is negligible and if it is less than 4.4, considerable exchange interaction is indicated in the solid complex [36][37][38]. The geometric parameter G for the compounds 2 and 4 are 3.258 and 2.448, respectively, which shows that exchange interaction is strong.…”