钯(Ⅱ)-苯并咪唑邻菲咯啉氨基酸配合物稳定性研究

用pH电位滴定法测定了以Pd2+为中心离子,以苯并咪唑邻菲咯啉(PIP)为第一配体,以甘氨酸根(gly-)、苯丙氨酸根(phe-)和亮氨酸根(leu-)为第二配体的(PIP)(Aa)+型混合配体配合物在37℃,μ(离子强度)=0 1(KNO3)乙醇/水混合介质(乙醇体积分数为10%、20%、30%、40%和50%)条件下的稳定常数lgK及表征常数ΔlgK和lgX·lgK值≥14,表明配合物具有极强的分子内键合作用,ΔlgK和lgX均大于相应的统计期望值,说明配合物获得了附加稳定性,并从分子内配体间的弱相互作用及熔化角度对配合物的稳定性进行了讨论·

Stability of the Ternary Complexes of Pd (Ⅱ)-Phenylimid-1,10-phenanthroline-amono Acid

The stability constant lgK and relevant characteristic constants ΔlgK and lgX of ternary complexes of Pd(PIP) (Aa)⁺ were determined by pH potential titration at 37°C with μ(ionic strength)=0.1 (KNO3) in the mixed medium of ethanol/H2O of which the ethanol volume ratio was 10%, 20%, 30%, 40% or 50% individually each time, Where PIP=Phenylimid-1,10-Phenanthroline was taken as the 1st ligand and Aa^-=gly^-, phe^- and leu^- as the 2nd one. The results show that lgK≥14 which implies that there is very strong bond in the ternary complexes, and that both ΔlgK and lgX are greater than the statistical expected value, which mean there is extra stability in the ternary complexes. The contributing ratio of electronic effect and hydrophobia effect (aromatic nucleus stacking) in extra stability was calculated. The results show that when the volume ratio of ethanol is 30%, hydrophobic effect (aromatic nucleus stacking) comes to its maximum value.