A rare all-Mn 2+ decametallic cage from distorted face-sharing cubes

Abstract

The preparation and crystal structure of a decametallic Mn II carboxylate cluster containing neutral 2-pyridinealdoxime, (py)C(H)NOH, and its anion, (py)C(H)NO −, is reported. The reaction between Mn(O 2CPh) 2 · 2H 2O and (py)C(H)NOH in CH 2Cl 2, in the presence of NH 4PF 6, produces the complex [Mn 10(O 2CPh) 12{(py)C(H)CNO} 6{(py)C(H)NOH} 2](PF 6) 2 · 2.6CH 2Cl 2 · 1.3H 2O ( 1 · 2.6CH 2Cl 2 · 1.3H 2O) in good yield. The cationic complex consists of ten Mn II ions assembled together by four η 1:η 1:η 3:μ 4 and two η 1:η 1:η 2:μ 3 oximato(−1) ligands, and four η 1:η 2:μ 3 PhCO 2 - ligands to form an unprecedented { Mn II 10 ( μ -OR ) 4 ( μ - OR ′ ) 2 ( μ 3 - OR ′ ) 4 } 10 + core, where R = PhCO and R′ = (py)C(H)N. Peripheral ligation is provided by a combination of bridging benzoates and chelating (py)C(H)NOH ligands. Dc magnetic susceptibility studies reveal the presence of dominant antiferromagnetic interactions leading to a spin ground-state of S T = 0. A survey of the ternary Mn II / RCO 2 - / ( py ) C ( H ) NOH reaction system is attempted with comparisons to previously reported complexes.