A Mixed‐Valence [Mn^IIMn^IIIMn^II] Complex of a Linear Phenol–bis(pyrazole) Ligand with an <i>S</i> = 3 Spin Ground State

Abstract

Abstract A novel ligand featuring one phenol and two pyrazole groups in a linear fashion was prepared. This donor facilitates the assembly of a mixed‐valence chain of Mn ions in the[Mn II Mn III Mn II ] sequence, with formula [Mn 3 (Hpbpz) 2 (OAc) 3 (MeOH) 3 ] ( 1 ). Complex 1 exhibits dominant antiferromagnetic coupling between adjacent pairs of Mn ions. A fit of the magnetic susceptibility data using the Hamiltonian H = –2 J 1 ( S 1 S 2 + S 2 S 3 ) – 2 J 2 ( S 1 S 3 ) yields coupling constants of J 1 = –3.14 cm –1 and J 2 = –0.39 cm –1 , which leads to a spin ground state of S T = 3. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2008)