Synthesis and thermal behaviour of cyclopentadienylnickel(II) thiolato Schiff base complexes. Molecular structures of Ni(η⁵-C₅H₅)(PBu₃)(SC ₆H₄NC(H)C₆H₄C₆H ₅)

The new complexes Ni(η⁵-C₅H₅)(PR₃)(SC ₆H₄NC(H)C₆H₄OC_nH _2n+1), Ni(η⁵-C₅H₅)(PR₃)(SC ₆H₄NC(H)C₆H₄C₆H ₅) and Ni(η⁵-C₅H₅)(PR₃)(SC ₆H₄NC(H)C₆H₄OCH₂C ₆H₅), (R=Ph or Bu; n=4, 6, 8, 10, 14, 16 and 20), were synthesised from equimolar amounts of Ni(η⁵-C₅H₅)(PR₃)Br (R=Ph or Bu) and the appropriate thiol ligand and were characterised by NMR and elemental analysis. In addition 1a and 3a were characterised by single crystal X-ray diffraction studies. These new complexes were also examined by thermal analytical methods (DSC and TGA) and polarising hot-stage microscopy, but were not found to exhibit any liquid crystalline behaviour. Thermal analysis showed that the complexes were generally stable up to about 180°C and decomposed finally to a species with empirical formula NiSC₆H₅. Two decomposition pathways were established, depending on the phosphine used.