Solvent control in the synthesis of [Mn(NCS)2(bpe)2(H2O)2] and [Mn(NCS)2(bpe)1.5(CH3OH)]n (bpe=1,2-bis(4-pyridyl)ethene):: structural analysis and magnetic properties

The combined use of pseudohalides and N,N'-type flexible organic spacers represents an excellent strategy for the preparation of extended systems in co-ordination chemistry. In this context, the formation of two Mn-II-NCS-bpe systems (bpe = 1,2-bis(4-pyridyl)ethene) of formula [Mn(NCS)(2)(bpe)(2)(H2O)(2)] 1 and [Mn(NCS)(2)(bpe)(1.5)(CH3OH)](n) 2 has been observed to be solvent-dependent. Both compounds were structurally characterised by means of X-ray single crystal diffraction and IR spectroscopy. Compound 1 consists of monomeric units where the manganese(II) ions are octahedrally co-ordinated. Compound 2 exhibits zigzag chains where the octahedral manganese(II) ions are alternatively bridged through N,N'-bpe and di-mu-(1,3)-NCS groups. Magnetic susceptibility measurements for 2 were consistent with the occurrence of weak antiferromagnetic coupling (J = -1.6 cm(-1)) through the thiocyanate bridges.