MAGNETIC-PROPERTIES OF 2 TRIMERIC CU(II) COMPLEXES WITH FERROMAGNETICINTRATRIMER INTERACTION

Two trimeric Cu(II) complexes CuEtBz and CuBuBz have been studied by m eans of SQUID magnetization, ac susceptibility and EPR methods. The ex perimental data have been interpreted in terms of a total spin Hamilto nian. The obtained results confirm ferromagnetic intratrimer coupling for both substances. CuEtBz can be well described as a superparamagnet composed of non- (or very weakly) interacting species with a spin val ue close to 3/2. A large zero-field splitting, attributed to anisotrop ic exchange, has been obtained for this compound. CuBuBz shows an inte resting nonlinear behaviour at low temperatures as a function of magne tic field which seems to be connected with intertrimer interactions.