A Conductivity Study of Unsymmetrical 2:1 Type “Complex Ion” Electrolyte: Cadmium Chloride in Dilute Aqueous Solutions

Abstract

Systematic and precise measurements of electrical conductivities of aqueous solutions of cadmium chloride were performed in the 2 × 10(-5)-1 × 10(-2) mol·dm(-3) concentration range, from 278.15 to 313.15 K. Determined conductances were interpreted in terms of molecular model which includes a mixture of two 1:1 and 2:1 electrolytes. The molar limiting conductances of λ(0)(CdCl(+), T) and λ(0)(1/2Cd(2+), T), the equilibrium constants of CdCl(+) formation K(T) and the corresponding standard thermodynamic functions were evaluated using the Quint-Viallard conductivity equations, the Debye-Hückel equations for activity coefficients and the mass-action equation. An excellent agreement between calculated and experimental conductivities was reached.

Structural Features of Europium(II)‐Containing Cryptates That Influence Relaxivity

“…The molar conductivities of metal complexes 1 , 2 , and 3 were 177 ± 3, 183 ± 6, and 199 ± 4 S cm 2 mol −1 , respectively. These values are consistent with 2:1 dissociation in water, [7] indicating that, on average, both chloride ions are dissociated from Eu II in solution. Further, 17 O-NMR line-broadening (Tables S2–S4) in the presence of Eu II -containing complexes is consistent with the presence of inner-sphere water, suggesting that chloride dissociation enables the coordination of water.…”

A EuII‐Containing Cryptate as a Redox Sensor in Magnetic Resonance Imaging of Living Tissue

“…To test whether the chloride ion remained coordinated in solution, we measured the molar conductivity of Eu II ‐222Fb in water. The molar conductivity was 211±1 S cm 2 mol −1 , which is consistent with compounds exhibiting a 2:1 dissociation in water 7. This observation indicates that, on average, no chlorides are coordinated to the Eu II center in solution.…”

A EuII‐Containing Cryptate as a Redox Sensor in Magnetic Resonance Imaging of Living Tissue

“…The molar conductivity was 211 ± 1 S cm 2 mol −1 , which is consistent with compounds exhibiting a 2:1 dissociation in water. [7] This observation indicates that, on average, no chlorides are coordinated to Eu II in solution. However, because molar conductivity is a colligative property, it does not provide further information regarding the coordination environment of Eu II -222Fb in solution.…”