Autor(es):
Clares, M. Paz 
; Aguilar, Juan ; Aucejo, Ricardo ; Lodeiro, Carlos ; Albelda, M. Teresa ; Pina, Fernando ; Lima, J. C. ; Parola, A. Jorge ; Pina, João ; Melo, J. Seixas de ; Soriano, Conxa ; García-Espana, Enrique
Data: 2004
Identificador Persistente: http://hdl.handle.net/10316/12875
Origem: Estudo Geral - Universidade de Coimbra
Descrição
The synthesis, protonation behavior, and Cu2+ and Zn2+ coordination chemistry of the novel bibrachial aza lariat ether (naphthalen-1-ylmethyl)[2-(20-2-[(naphthalen-1-ylmethyl)amino]ethyl-3,6,9,17,20,23,29,30-octaazatricyclo[23.3.1.1*11,15*]triaconta-1(29),11(30),12,14,25,27-hexaen-6-yl)ethyl]amine (L) are discussed. The macrocycle, which has two aminoethyl naphthyl moieties symmetrically appended to a 2:2 azapyridinophane structure, displays, in the pH range 2−11, six protonation steps that correspond to the protonation of the secondary amino groups. Steady-state fluorescence measurements show emissions due to the monomer and to the excimer formed between the two naphthalene fragments of the macrocycle. The time-resolved fluorescence data, obtained by the time-correlated single photon counting technique, show that a significant percentage of excimer is preformed as ground-state dimers. The ligand L forms with the metal ions Cu2+ and Zn2+ mono- and dinuclear complexes in aqueous solution. The influence of metal coordination in the fluorescence emission of L is analyzed. The acid−base, coordination capabilities, and emissive behavior of L are compared with those presented by its synthetic precursor L1, which has a tripodal tris(2-aminoethyl)amine structure functionalized at one of its terminal amino groups with a naphthyl moiety
