Palladium(II) and copper(II) complexes [Pd(L1)Cl2], Pd(L3)Cl2], [Cu(L1)Cl2], Cu(L3)Cl2], [Pd(L2)][BF4]2, [Pd(L4)Cl]-BF4, [Cu(L2)][NO3]2 and Cu(L4)Cl]PF6 of the nitrile (L1 and L3) and amino (L2 and L4) pendant arm derivatives of 1-thia-4,7-diazacyclononane ([9]aneN2S) and 7-aza-1,4-dithiacyclononane ([9]aneNS2) have been prepared and fully characterised.In each case, a square-pyramidal coordination sphere is observed at both metal ions with either one or two Cl− anions completing the donor set. The tridentate ninemembered macrocyclic moiety adopts a [333] conformation in all the complexes obtained. The five-membered chelate rings involving the donor atoms of the basal plane adopt a gauche configuration with very similar degrees of puckering. The ‘‘innocent’’ nitrile pendant arms in L1 and L3 do not bind to the metal ions, but still appear to influence the binding of the tridentate macrocyclic frameworks via the tertiary amine sites.