Magnetic properties of a linear trinuclear manganese compound [Mn₃(PhCO₂)₆(Bipy)₂] · H₂O

The reaction of the trinuclear oxo-centered mixed-valence complex [Mn3O(O2CPh)(6)(Py)(2)(H2O)] with 2,2'-bipyridyl (Bipy) and another potential tripodal ligand affords the title compound [Mn-3(PhCO2)(6)(Bipy)(2)] center dot H2O in good yield. The X-ray crystallographic diffraction study reveals that three mangenese ions are arranged in a linear mode with Mn-center-Mn-terminal and Mn-terminal-Mn-terminal diatances of 3.588 and 7.176 , respectively. Molar magnetic susceptibility of the compound gradually decreases from 12.23 (300 K) to 4.45 cm(3) K mol(-1) (2 K). Taking into account the structure of this compound, the data in the 2.0-300 K range were fit to the appropriate theoretical expression to give J = -2.73 cm(-1), rho = 2.07%, N (a) = -0.0004 cm(3) mol(-1), g = 1.992, and R (2) = 0.99996. The magnetization versus external magnetic field measurements at 2 K shows that the ground state is S (T) = 5/2.