Synthesis and H+, Cu2+, and Zn2+ Coordination Behavior of a Bis(fluorophoric) Bibrachial Lariat Aza-Crown

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• 作者：M. Paz Clares ; Juan Aguilar ; Ricardo Aucejo ; Carlos Lodeiro ; M. Teresa Albelda ; Fernando Pina ; J. C. Lima ; A. Jorge Parola ; Joã ; o Pina ; J. Seixas de Melo ; Conxa Soriano ; and Enrique Garcí
• 刊名：Inorganic Chemistry
• 出版年：2004
• 出版时间：September 20, 2004
• 年：2004
• 卷：43
• 期：19
• 页码：6114 - 6122
• 全文大小：192K
• 年卷期：v.43,no.19(September 20, 2004)
• ISSN：1520-510X

文摘

The synthesis, protonation behavior, and Cu²⁺ and Zn²⁺ coordination chemistry of the novel bibrachial aza lariatether (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, whichhas two aminoethyl naphthyl moieties symmetrically appended to a 2:2 azapyridinophane structure, displays, in thepH 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 thetwo naphthalene fragments of the macrocycle. The time-resolved fluorescence data, obtained by the time-correlatedsingle photon counting technique, show that a significant percentage of excimer is preformed as ground-statedimers. 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, coordinationcapabilities, and emissive behavior of L are compared with those presented by its synthetic precursor L1, whichhas a tripodal tris(2-aminoethyl)amine structure functionalized at one of its terminal amino groups with a naphthylmoiety.