Novel Cu(II)Cd(II) macrocyclic complex that hydrolyzes an activated phosphate diester
作者:Jian Gao、Arthur E Martell、Joseph Reibenspies
DOI:10.1016/s0020-1693(02)00694-1
日期:2002.2
The dinucleating macrocyclic ligand 3,6,9,17,20,23-hexaaza-29,30-dihydroxy-13,27-dimethyl-tricyelo[23,3,1,1(11.15)] 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 trichnic, space group P1, with cell constants a = 13.2675(10) Angstrom, b = 16.4655(13) Angstrom, c = 17.9502(14) Angstrom, alpha = 87.78(10), beta = 68.69(10), gamma = 74.81(10), V = 3517.6(3) Angstrom 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. (C) 2001 Elsevier Science B.V. All rights reserved.