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 re presents an excellent strategy for the preparation of extended systems in c o-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)(H2 O)(2)] 1 and [Mn(NCS)(2)(bpe)(1.5)(CH3OH)](n) 2 has been observed to be sol vent-dependent. Both compounds were structurally characterised by means of X-ray single crystal diffraction and IR spectroscopy. Compound 1 consists o f monomeric units where the manganese(II) ions are octahedrally co-ordinate d. Compound 2 exhibits zigzag chains where the octahedral manganese(II) ion s are alternatively bridged through N,N'-bpe and di-mu-(1,3)-NCS groups. Ma gnetic susceptibility measurements for 2 were consistent with the occurrenc e of weak antiferromagnetic coupling (J = -1.6 cm(-1)) through the thiocyan ate bridges.