ESR spectra of the square pyramidal iodo [difluoro[3,3′-(trimethylenedinitrilo)-bis(2-butanone oximato)] borato] copper(II) complex

The single crystal ESR spectrum of the square pyramidal iodo[difluoro[3,3′-(trimethylenedinitrilo)-bis(2-butanoneoximato)] borato] copper(II), Cu(cyclops)I, complex diluted into the nickel(II) lattice has been recorded. The spin Hamiltonian parameters (g1 = 2.05, g2 = 2.07, g3 = 2.18, A3 = 190 × 10−4 cm−1) have been interpreted using a symmetry independent angular overlap model. This analysis shows that the in-plane field is fairly strong thus explaining the observed diamagnetism of the Ni(cyclops)X adducts.