一种去质子的MH_(-2)L型配合物稳定常数的测定

DETERMINATION OF THE STABILITY CONSTANT OF A DEPROTONATED MH-2_L TYPE COMPLEX

用pH—电位法测定一种新合成配体的加质子常数及其和4种金属离子所形成的去质子的MH_2L型配合物的稳定常数,所得浓度平衡常数的对数值(lob K_(MN)_(-2)L)分别为:-9.97(Mn^(2+));-9.2(Co^(2+));-11.7(Ni^(2-));-6.81(Cu^(2+))。配体的累积加质子常数为:β_1~H=1.31×10~3,β_2~H=7.67×10~4。所得结果和文献报导的、结构上类似的配合物稳定常数接近。

Determinations of both the protonation constants of a synthesized ligand and the stability constants of complexes that the ligand fromed with four metal ions were accomplished by pH-potentiometric method, Logarithmic values of the concentration equilibrium constants are -9.97 (Mn^(2+) complex), -9.21 (Co^(2+) complex), -11.7 (Ni^(2+) complex) and -6.81(Cu^(2+) complex). And the cumulative constants of proton addition of the ligand under the same experimental condition are β~H_1= 1.31×10 and β~H_2= 7.67×104. Above mentioned stability constants are close to those of previously reported, similar complexes in structure.