title: Luminescent complexes of silver(I) with pyridylbis(3-hexamethyleneiminyl thiosemicarbazone): effect of the counterion on the nuclearity.
abstract: The reaction of pyridylbis(3-hexamethyleneiminyl thiosemicarbazone) (H(2)Plhexim) with various silver(I) salts and metal-ligand ratios led to the isolation of different complexes of the formulae [Ag(NO(3))(H(2)Plhexim)]·H(2)O (1), [Ag(2)(NO(3))(H(2)Plhexim)(CH(3)OH)](NO(3)) (2), [Ag(2)(ClO(4))(2)(H(2)Plhexim)] (3), [Ag(HPlhexim)]·xH(2)O (4), [Ag(HPlhexim)] (4a), [Ag(2)(Plhexim)(PPh(3))(4)]·2MeOH (5) and [Ag(4)(Plhexim)(2)]·DMF (6). The complexes were fully characterized by elemental analysis, ESI mass spectrometry, IR and NMR ((1)H, (31)P) spectroscopy. The structures of 4a, 5 and 6 were also identified by single crystal X-ray structure determination. The concentration dependence on the absorption spectra of the methanolic solutions indicates polymerization equilibria in the ground state in both the ligand and the complexes. While H(2)Plhexim is essentially non-fluorescent, complexes 1-5 fluoresce more strongly by comparison. This fluorescent behavior is consistent with the monomeric or dimeric nature of the complexes.
authors.affiliation: Universidad de Santiago de Compostela, Departamento de Química Inorgánica, Facultad de Farmacia, Santiago de Compostela, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Castiñeiras
authors.forename: Nuria
authors.initials: N
authors.lastname: Fernández-Hermida
authors.forename: Isabel
authors.initials: I
authors.lastname: García-Santos
authors.forename: José Luis
authors.initials: JL
authors.lastname: Pérez-Lustres
authors.forename: Iria
authors.initials: I
authors.lastname: Rodríguez-González