Pegylation of 1,4,8,11-Tetraazacyclotetradecane (Cyclam) and its Copper(II) Complexation

Two novel star-like cyclam derivatives with appended four amino groups and four PEG-arms have been synthesized. The complex formation of cyclam and the cyclam derivatives and with Cu(II) has been studied by UV-Vis and time-resolved laser-induced fluorescence (TRLFS) measurements. The cyclam ligands investigated form 1:1 complexes with Cu(II). Rapid complex formation was found for cyclam and the pegylated derivative. By way of contrast, complete attainment of complexation between Cu(II) and cyclam ligand having external primary amino groups needs approx. 1 hour. By TRLFS measurements a quench effect of the Cu(II) on the fluorescence of the ligand was found. This behaviour was used to determine the complex formation between Cu(II) and the ligands.