title: Novel fluorescent cationic silver thiosemicarbazone clusters containing different eight-membered Ag(4)S(4) metallacycles.
abstract: The reaction of silver acetate and silver nitrate with the new phosphinethiosemicarbazone ligand 2-(2-(diphenylphosphino)benzylidene)-N-ethylthiosemicarbazone (HLPEt) gave rise to the complexes [Ag(LPEt)](4).2MeOH (1) and [Ag(2)(LPEt)(HLPEt)](2).(NO(3))(2) (3). Slow crystallization of the mother liquors obtained from the synthesis of 1 and 3 afforded suitable crystals of [Ag(2)(LPEt)(HLPEt)](2)(CH(3)COO)(2).6MeOH (2) and [Ag(2)(LPEt)(HLPEt)](2)(NO(3))(2).2MeOH.2H(2)O (4), respectively. Complexes 2 and 4 are tetranuclear silver clusters displaying a similar Ag(4)S(4)P(4) core, but containing different sizes, conformations for the Ag(4)S(4) metallacycles, and crystal packings. The four complexes are strongly luminescent in methanol solutions. A comparison between the emission bands of compounds 1-4 lead us to conclude that the luminescence is notably affected by the charge and the counterion of the cluster.
authors.affiliation: Departamento de Química Inorgánica, Facultade de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela, 15782 Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Castiñeiras
authors.forename: Rosa
authors.initials: R
authors.lastname: Pedrido
mesh_terms: D002412:Cations / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D005453:Fluorescence; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013882:Thiosemicarbazones / Q000737:chemistry*
chemical_list: D002412:Cations; D008024:Ligands; D009942:Organometallic Compounds; D013882:Thiosemicarbazones; D012834:Silver