Synthesis, crystal structures and magnetic properties of methoxido-bridged dinuclear Mn III complexes derived from tri-dentate chelating ligands

Two new doubly methoxido-bridged Mn III dinuclear complexes, [Mn III (mphp)( μ -OCH 3 )(CH 3 OH)] 2 ·2CH 3 OH ( 1 ) and ([Mn III (ahbz)( μ -OCH 3 )(CH 3 OH)] 2 ·2CH 3 OH ( 2 ), have been synthesized by using the tridentate ligands H 2 mphp (H 2 mphp = 2-methyl-6-(pyrimidin-2-yl-hydrazonomethyl)-phenol) and H 2 ahbz (H 2 ahbz = N-(2-amino-propyl)-2-hydroxy-benzamide). The complexes have been characterized structurally by single-crystal X-ray diffraction analysis and magnetic measurements.

Complexes 1 and 2 have a similar dimeric molecular structure. Two [Mn(L)(CH 3 OH)] + moieties (L 2- = mphp 2- or ahbz 2- ) are bridged by two μ -OCH 3 - groups in the axial-equatorial asymmetric manner. The coordination geometry of Mn III is an axially elongated octahedron with two oxygens of a methanol ligand and a methoxido ligand situated at the axial positions.