The degree of formation of stacked isomer decreses Pd(phen)(UTP)->Pd(bpy)(UTP)->Pd(trp)(UTP) -.混配合物中的芳环堆积作用按下列顺序减小:Pd(Phen)(UTP)~(-)>Pd(bpy)(UTP)~(-)>Pd(trp)(UTP)~( -).