Dinuclear nickel(II) complexes with a tridentate nitrito bridge and terminal thiocyanato ligands. Crystal structure and magnetic properties

Abstract

The µ-(η¹-N∶η²-O,O)-nitrito dinuclear compounds [Ni₂(µ-NO₂)(NCS)₃(Medpt)₂]·H₂O 1 and [Ni₂(µ-NO₂)(NCS)₃(dpt)₂] 2, and the mononuclear nitrito compounds [Ni(NO₂)(NCS)(Medpt)] 3 and [Ni(NO₂)(NCS)(Medien)] 4, where Medpt = bis(3-aminopropyl)methylamine, dpt = bis(3-aminopropyl)amine and Medien = bis(2-aminoethyl)methylamine, have been synthesized and characterised. The crystal structures of 1–4 have been determined by single-crystal X-ray analysis. The thiocyanate ligand appears to stabilise the tridentate co-ordination mode of the nitrito ligand. The magnetic behaviour of the dinuclear compounds 1 and 2 was recorded between 300 and 4 K, showing antiferromagnetic coupling in both cases. The magnetic susceptibility data were fitted by the expression for a dinuclear nickel(II) compound giving the parameters J = –12.8 cm^–1, g = 2.17 and J = –12.2 cm^–1, g = 2.27 for 1 and 2 respectively.