Diaqua[N,N′-bis(5-methoxysalicylidene)ethylenediaminato- κ⁴O,N,N′,O′]-manganese(III) perchlorate, aqua[N,N′-bis(3,5-dichlorosalicylidene)-ethylenediaminato- κ⁴O,N,N′,O′]-(methanol-κO)manganese(III) perchlorate and bis[μ-N,N′-bis-(3-methoxysalicylidene)ethylene- diaminato-κ⁵O,N,N′,O′

The title compounds, a hydrogen-bonded linear chain, [Mn-(C ₁₈H₁₈N₂O₄)(H₂O) ₂]ClO₄, (I), a hydrogen-bonded pseudodimer, [Mn(C ₁₆H₁₀Cl₄N₂O₂)(CH ₄O)(H₂O)]ClO₄, (II), and a dimer, [Mn ₂(C₁₈H₁₈N₂O₂) ₂(CH₄O)₂](ClO₄)₂, (III), respectively, have been structurally characterized. The three complexes are completely different in their structural features, despite identical counter-anions and only slight modification of the substituents in the ligands. Complex (I) affords an elongated octahedral coordination environment, with axial Mn-O(water) distances of 2.259 (3) and 2.313 (3) Å, which forms hydrogen-bonded linear chains along the crystallographic c axis. Hydrogen-bonded pseudo-dimeric compound (II) also affords an elongated octahedral coordination environment, with axial Mn-O(CH₃OH) = 2.222 (3) Å and Mn-O(water) = 2.266 (3) Å. Dimeric complex (III) is centrosymmetric and consists of distorted octahedral Mn atoms, with axial Mn-O(CH ₃OH)=2.242 (2) Å and Mn-O(phenolate) = 2.348 (1) Å, connected via bridging O atoms from one of the ligands. The magnetic properties of the three complexes are described.