Synthesis, characterisation and spectroscopic properties of ruthenium(II)-2,2':6',2''-terpyridine coordination triades X-ray structures of 4'-(N,N-dimethylamino)-2,2':6',2''-terpyridine and bis(4'-(N,N-dimethylamino)-2,2':6',2''-terpyridine)ruthenium(II) hexafluorophosphate acetonitrile solvate

Abstract

The synthesis of all twenty-one possible homoleptic and heteroleptic [Ru(Xtpy)(Ytpy)]2+ compounds from the 4'-substituted-2,2':6',2-terpyridines (tpy, Cltpy, EtOtpy, HOtpy, Me2Ntpy and Phtpy) is described. The synthesis of the ligands EtOtpy and Me2Ntpy is described in detail, the latter being prepared by a metal-mediated nucleophilic displacement of halide from [Fe(Cltpy)2]2+ followed by demetallation. The H-1 NMR properties of the complexes are discussed in detail, as are their electrochemical properties. The redox properties are correlated with a new Hammett parameter, sigma', which is defined for the ligand set. Deprotonation reactions of the HOtpy complexes have been investigated. The crystal and molecular structures of the free ligand Me2Ntpy (C17H16N4, orthorhombic, space group Pnab, a = 7.857(2)angstrom, b = 10.318(2) angstrom, c = 17.555(4) angstrom, V = 1423 angstrom3 and Z = 4) and the complex [Ru(Me2Ntpy)2] [PF6]2.MeCN (C36H35N9P2F12Ru, monoclinic, space group C2/c, a = 11.801(4) angstrom, b = 25.335(8) angstrom, c = 14.874(4) angstrom, beta = 107.64(2)-degrees, V = 4238 angstrom3 and Z = 4) are described.