A new dioxotetraamine ligand appended with fluorenyl and its copper(II) complex. Synthesis, crystal structure and solution behavior

A new dioxotetraamine ligand 6-(9-fluorenyl)-1,4,8,11-tetraazaundecane-5,7-dione (L) and its copper(II) complex have been synthesized. Detailed studies have been made on solution chemistry of Cu(II), Ni(II) and Co(II) complexes of the ligand by pH-potentiometric and fluorimetric titration as well as cyclic voltammetry. The coordination of Cu2+ and Ni2+ quenches the fluorescence of fluorenyl in the ligand through an electron transfer mechanism. The crystal structure of [Cu(H−2L)] was determined.