Restoration of catalytic activity by replacement of a coordinated amide group: Synthesis and laser-induced luminescence studies of the phosphate diester transesterification catalyst [Eu(NBAC)]{sup 3+}

Here the authors report the preparation, solution characterization, and catalytic properties of the Eu(III) complex of the NBAC ligand (NBAC = 1-(4-nitrobenzyl)-4,7,10-tris-(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane). The nitrobenzyl group was chosen as a precursor to an isothiocyanate group for conjugation of the complex to a modified oligonucleotide. Such catalysts may be useful for the sequence-specific cleavage of RNA.