A spin-frustrated star-shaped heterotetranuclear (CrMn3II)-Mn-III species and its magnetic and HF-EPR measurements

摘要

A tetranuclear complex [(CrMn3II)-Mn-III(PyA)(6)Cl-3] 1 containing pyridine-2-aldoximato monoanion, PyA, has been structurally and magnetochemically characterized. The compound is a rare example of a tetranuclear star-shaped metal topology containing pyridine-2-aldoximato ligands. Static magnetic studies have demonstrated very weak antiferromagnetic exchange interactions between the paramagnetic centers (S-Cr = 3/2 and S-Mn = 5/2) resulting in closely spaced low-lying levels, which undergo splitting and crossing. Preliminary high-field EPR measurements (20 < v < 388 GHz) indicate the presence of zero-field splitting D of the order of 0.7 cm(-1).