Two new supramolecular malonato complexes of manganese(II): synthesis, crystal structure and magnetic property

Abstract

A mononuclear [Mn(mal)(bipy)(H₂O)₂] (1) and a dinuclear [Mn₂(mal)(phen)₃(H₂O)₂(Cl)]Cl (2) (mal=malonate dianion; bipy=2,2′-bipyridine and phen=1,10-phenanthroline) have been synthesised and structurally characterized by X-ray crystallography. The structure of complex 1 shows that each Mn(II) is linked with one bipy, two water molecules and a malonate ligand forming distorted octahedral environment and each mononuclear fragment through H-bonding interactions form 2D supramolecular network. The structure of complex 2 comprises to an asymmetric dinuclear cation which is bridged by a single anti–anti malonate ligand and chloride anions. The two distorted Mn(II) centres are separated by large distance 6.256(3) Å due to the anti–anti bridging mode. The magnetic behavior of complex 2 studied in the temperature range 300–2 K corresponds to a weak antiferromagnetic coupling through the MnOCOMn anti–anti conformation. The magnetic data were fitted based on H=−2JS¹·S², yielding the intramolecular coupling constant J=−0.35 cm^-1 with g=1.92 and R=1.255×10^-4. A mononuclear [Mn(mal)(bipy)(H₂O)₂] (1) and a dinuclear [Mn₂(mal)(phen)₃(H₂O)₂(Cl)]Cl (2) (mal=malonate dianion; bipy=2,2′-bipyridine and phen=1,10-phenanthroline) have been synthesised and structurally characterized by X-ray crystallography. The structure of complex 1 shows that each mononuclear fragment through H-bonding interactions forms 2D supramolecular network. The structure of complex 2 comprises to an asymmetric dinuclear cation which is bridged by a single anti–anti malonate ligand and chloride anions. The magnetic behavior of complex 2 studied in the temperature range 300–2 K and it corresponds to a weak antiferromagnetic coupling through the MnOCOMn anti–anti conformation.