Abstract
Electron paramatic resonance has been studied in polycrystalline undiluted samples of several salicylaldimine derivatives of known crystal structure. In two studied compounds (bis (N‐isopropylsalicylaldiminato) Cu and bis (N‐t‐butylsalicylaldiminato) Cu) the structure of the nearest environment is intermediate between tetrahedral and square coplanar. The obtained values and signs of anisotropy of the g‐factors show the essential difference between the properties of the copper ion in these two compounds and that in the case of the planar complex. On the basis of a theoretical analysis it is found that the electronic properties of the copper (II) ion in bis (N‐isopropylsalicylaldiminato) Cu and bis (N‐t‐butylsalicylaldiminato) Cu can be explained by consideration of the nearest environment symmetry as a elongated tetrahedron with d p ground state and taking into account the admixture of upper 4p and 4s states into the 3d wave functions. The values of the covalency and admixtures of the 4p and 4s states are estimated for bis (N‐isopropylsalicylaldiminato) Cu. A suggestion is made about the variation of these values under the transition to the more distorted structure in bis (N‐t‐butylsalicylaldiminato) Cu.