Chemistry of hafnium: Complexes of hafnium(IV) with 2-amino-1-cyclopentene-1-dithiocarboxylic acid and its N-alkyl derivatives

The chemistry of bidentate (S,S−) donor ligands 2-amino-1-cyclopentene-1-dithiocarboxylic acid (HL) and itsN-alkyl derivatives [alkyl = Me (HL1), Et(HL2) and Bu(HL3)] with hafnium(IV) chloride in 1∶1, 1∶2, 1∶2, 1∶3 and 1∶4 molar ratios is described. These complexes were characterized by elemental analysis, u.V., i.r. and n.m.r. spectral studies. Disulphur chelation with coordination numbers 5, 6, 7 and 8 was observed in all the metal chelates.