三元混配铂(Ⅱ)配合物的稳定性和分子内芳环堆积效应研究

摘要

The stability constants of the ternary mixed-ligand complexes of Pt(ArL)(NTP)n- (n=2 or 3) have been determined by potentiometric pH titration in aqueous solution (I=0.1 mol/L, KNO3; 25℃), where NTP refers to adenosine 5′-triphosphate (ATP) and uridine 5′-triphosphate (UTP); ArL refers to 1,10-phenanthroline (Phen), 2,2′-bipyridyl (Bpy), and L-tryptophane (Trp). The stability difference between the ternary complexes and the binary complexes has been compared and discussed. The increased stability in the ternary mixed-ligand complexes can be attributed to the cooperative effect of πA-πB and the intramolecular ligand-ligand aromatic-ring stacking interaction. The extent of the intramolecular aromatic-ring stacking interaction in the ternary platinum (Ⅱ) complexes has been calculated, which is in accord with the size of the aromatic rings forming the stack.%用pH电位滴定法测定了铂(Ⅱ)与核苷酸NTP (NTP为腺苷5′-三磷酸和尿苷5′-三磷酸)和另一芳环系列配体ArL形成的三元混配配合物Pt(ArL)(NTP)n-(ArL=Phen, Bpy和Trp; n=2或3)在水溶液中的稳定常数(I=0.1 mol/L, KNO3; 25℃).用ΔlogKPt比较了二元和三元混配配合物的稳定性差异,认为三元混配配合物稳定性的增加可归因于π-酸与π-碱之间的合作效应和分子内芳环配体的堆积作用.