An Extended Metal Chain with the 2,7-Bis(dipyridyldiamino)-1,8-naphthyridine (H(4)bdpdany) Ligand - The Longest Even-Numbered Metal Chain Complex

Abstract

A decanickel extended metal atom chain (EMAC) complex with a new pyridyl-and naphthyridyl-modulated ligand (H(4)bdpdany) was synthesized. Analysis of the crystal structure of complex [Ni-10(mu(10)-bdpdany)(4)(NCS)(2)](PF6)(2) (1) shows that all of the bdpdany(4-)ligands bind the metal in an all-syn conformation, and structural data reveals short Ni center dot center dot center dot Ni distances in the range 2.36-2.23 angstrom. Temperature-dependent magnetic measurements performed on two independent high-spin nickel(II) ions of complex [Ni-10(mu(10)-bdpdany)(4)(NCS)(2)](PF6)(2) (1) demonstrate that the metal chain is antiferromagnetic. The longer distance between the two terminal high-spin nickel(II) ions relative to those in tetranickel and hexanickel strings causes a decrease in the magnitude of the antiferromagnetic interaction.