MOLECULAR HELICITY IN INORGANIC COMPLEXES - BINUCLEAR AND TRINUCLEAR COMPLEXES OF 2,2'-6',2''-6'',2'''-6''',2''''-6'''',2'''''-SEXIPYRIDINE AND THE CRYSTAL AND MOLECULAR-STRUCTURE OF BIS(MU-2,2'-6',2''-6'',2'''-6''',2''''-6'''',2'''''-SEXIPYRIDINE-KAPPA-3N,N',N''-KAPPA-3N''',N'''',N''''')DICADMIUM HEXAFLUOROPHOSPHATE-ACETONITRILE (1/4)

The potentially sexidentate ligand 2,2':6',2":6",2"':6"',2"":6"",2""'-sexipyridine (L) has been prepared and shown to demonstrate considerable structural versatility in forming double helical binuclear complex cations of the type [M2L2]4+ (M = Mn(II), Fe(II), Cu(II) or Cd(II)), or [M3L2]3+ (M = Cu(I) and Ag(I)). A binuclear palladium(II) complex with a metal:ligand stoichiometry of 2:1 has also been characterised. The electrochemical properties of these complexes are reported, together with redoxinitiated interconversions of [Cu3L2]n+ and [Cu2L2]n+ species. The crystal and molecular structure of the double helical complex [Cd2L2][PF6]4.4MeCN [space group C2/c, a = 20.466(8), b = 18.872(6), c = 20.617(5) angstrom, beta = 111.98(2)-degrees, R = 0.0599, R' = 0.0634] is reported; the two metal centres are separated by 4.173(4) angstrom and coplanar pyridyl rings of the two independent ligands within the cation show short pi-stacking interactions.