铂(Ⅱ)混配配合物的分子内芳环堆积效应

Study on the Intramolecular Aromatic-ring Stacking Interaction of the Ternary Mixed-ligand Complexes of Platinum(Ⅱ)

用 p H电位滴定法测定了铂 ( )与核苷酸 NTP(腺苷 5′-三磷酸和尿苷 5′-三磷酸 )和另一芳环系列配体 Ar L形成的三元混配配合物 Pt(Ar L) (NTP) n-(Ar L=Phen,Bpy和 Trp;n=2或 3)在水溶液中的稳定常数 (I=0 .1 mol/L,KNO3 ;2 5℃ ) .用Δlg KPt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 -π-碱之间的合作效应和分子内芳环配体的堆积作用 .

The stability constants of the ternary mixed ligand complexes of Pt(NTP)(ArL) n- (n =2 or 3) have been determined by potentiometric pH titration in aqueous solution ( I =0.1mol/L, KNO 3, 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 tryptophan (Trp). The stability difference between the ternany complexes and the binary complexes has been compared and discussed. The increased stability in ternany mixed ligand complexes was attributed to the cooperative effect of π A π B and the intramolecular ligand ligand aromatic ring stacking interaction. The extent of the stacking interaction in the ternary platinum complexes was calculated, which is in accordance with the size of the aromatic rings forming the stacks.