STABILITY-CONSTANTS OF TIN(II) AND CALCIUM DIPHOSPHONATE COMPLEXES
STABILITY-CONSTANTS OF TIN(II) AND CALCIUM DIPHOSPHONATE COMPLEXES
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DOI：
10.1016/0162-0134(84)85040-0
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发表时间：
1984-01-01
影响因子：
3.9
通讯作者：
VANDERLINDEN, JGM
中科院分区：
文献类型：
--
作者：
CLAESSENS, RAMJ;VANDERLINDEN, JGM
Stoichiometric stability constants were determined for Sn(II) and Ca species with 6 different diphosphonates in 0.1 M Me4NNO3-containing solutions. Several protonated, hydroxylated, mono- and binuclear metal complexes were identified. The relative amounts of these species present in aqueous solutions were strongly influenced by the pH. Diphosphonates stabilized supersaturated Sn(OH)2 solutions. The order of the observed increasing stability of Sn(II) disphosphonates MDP [methane diphosphonic acid] < DPD [2,3-dicarboxypropane-1,1-diphosphonic acid] < DCMDP [dichloromethanediphosphonic acid] .simeq. EHDP [1-hydroxyethane-1,1-diphosphonic acid] < pCPMDP [p-chlorophenylmethanediphosphonic acid] is in accordance with the order of decreasing 99mTc uptake in bone. The experimental data were obtained from acidimetric titrations. The stability constants were calculated from the titration curves by means of a computerized version of a nonlinear least-squares fitting procedure. [99mTc diphosphonates are used for imaging of skeletal disorders. They are usually prepared by the reduction of 99mTc-TcO4- by a large excess of tin(II) in the presence of a diphosphonate (now mostly MDP).].
