COORDINATION GEOMETRIES AND COOPERATIVE ORDERING EFFECTS IN COPPER(II) COMPLEXES WITH TRIDENTATE SCHIFF-BASE DIANIONS .3. EPR STUDY ON N-SALICYLIDENEGLYCINATOCOPPER(II) COMPLEXES WITH THIOUREA DERIVATIVES

N-Salicylideneglycinatocopper(II) complexes of the composition Cu(salg ly) (L(s))(H2O)(x) were synthesized with L(s) = thiourea, N-methylthio urea, N,N,N',N'-tetramethylthiourea, N-ethylthiourea, N,N'-diethylthio urea, N-(2-chlorphenyl)thiourea, N,N'-diphenylthiourea, N,N'-ethylenet hiourea, N,N'-phenylenethiourea [equivalent to 1,3-dihydrobenzimidazol e-2-thione]; and x = 0 or 1. The EPR spectra gave evidence for square- pyramidal coordination around Cu-II, however, with a different strengt h of axial interaction originating from an oxygen atom from the adjace nt complex molecule. In the case of monohydrates bonding of a water mo lecule is also possible. In two examples, even square-planar geometry, without any significant axial interaction can be assumed. The great v ariety of cooperative ordering phenomena in the structure, which is ca used mainly by the extraordinary flexibility of the Schiff base ligand , results in coupling patterns ranging from ferrodistortive to antifer rodistortive. These patterns are remarkably influenced by the substitu tions on thiourea. Both the global and local symmetry effects are anal ysed with the aid of EPR spectroscopy.