Novel Cu(II)Cd(II) macrocyclic complex that hydrolyzes an activated phosphate diester

The dinucleating macrocyclic ligand 3,6,9,17,20,23-hexaaza-29,30-dihydroxy-13,27-dimethyl-tricyclo[23,3,1,111,15] triaconta-1(28),11,13,15(30),25,26,-hexaene(BDBPH) was synthesized from [2+2] condensation between a diethylenetriamine lead(II) mononuclear complex and diformal-p-cresol. By stepwise synthesis, the heterodinuclear Cu(II)Cd(II) complex was obtained. The single crystal was triclinic, space group P1, with cell constants a=13.2675(10) Å, b=16.4655(13) Å, c=17.9502(14) Å, α=87.78(10), β=68.69(10), γ=74.81(10), V=3517.6(3) Å and Z=4. Potentiometric titration reveals that Cu(II)Cd(II)BDBPHOH species dominate in basic solution from pH 7 to 12. In the hydrolysis of BNP, this dinuclear complex can provide both Lewis acid and base sites to an active phosphate diester in which nucleophilic OH− attacks the substrate to fulfill the hydrolysis cycle. In this system the synergic two functional groups in one catalyst molecule exerted remarkable catalytic activity towards hydrolysis of BNP.