Manganese(II) complexes having pseudohalide coordination: Synthesis, IR spectroscopy and X-ray crystal structures of [Mn(L¹)(NCS)₂] and [Mn(L²)(NCS)₂] compounds involving Schiff bases

Abstract

The synthesis, characterisation and properties of two manganese(II) complexes with thiocyanate coordination [Mn(L¹)(NCS)₂] (<b>1</b>) and [Mn(L²)(NCS)₂] (<b>2</b>) (L¹ and L² = tetradentate ligand; derived from bis condensation of pyridine-2- carboxaldehyde and 1,3-diaminopropane, and 2-benzoyl pyridine and 1,3-diaminopropane, respectively) is described. The magnetic moments of <b>1</b> and 2 are respectively 5.95 and 5.86 BM at 298 K, indicating high-spin (idealised t_2g³e_g² , <i>S</i>== 5/2) electronic configuration. The X-band EPR in 1:1 DMF-toluene glass (77 K) shows the 55Mn hyperfine structure at <i>g </i>= 2 with peak-to-peak separation of about 85 <i>G</i>. The structures <b>1</b>and 2 have been determined by single crystal X-ray diffraction studies, showing thereby that the manganese atom is hexacoordinated with an unusual distortion in the coordination sphere of this type of linear tetradentate ligand and thiocyanato anion acting as a terminal donor.