Skanthakumar S, Antonio Mark R, Soderholm L
Heavy Elements and Separation Sciences Group, Argonne National Laboratory, Argonne, IL 60439, USA.
Inorg Chem. 2008 Jun 2;47(11):4591-5. doi: 10.1021/ic702478w. Epub 2008 May 3.
The solution coordination environments of pentavalent and hexavalent Np are studied by high-energy X-ray scattering. Np5+ and Np6+ both exist as the neptunyl moiety coordinated with five equatorial waters at Np-O distances of 2.46(2) and 2.37(2) A, respectively. NpO2(2+) also has a second coordination sphere of 6-10 waters at 4.37(3) A. The NpO2+ scattering is complicated by the presence of scattering at about 4.2 A that is attributed to Np-Np cation-cation interactions. The analysis of changing intensity of this peak as a function of Np concentration is used to determine a stability constant of Keq=0.74(9) M(-1) for the dimeric complex.
通过高能X射线散射研究了五价和六价Np的溶液配位环境。Np5+和Np6+均以酰基部分形式存在，分别与五个赤道面水分子配位，Np - O距离分别为2.46(2) Å和2.37(2) Å。NpO2(2+)在4.37(3) Å处还有一个由6 - 10个水分子组成的第二配位层。NpO2+的散射因在约4.2 Å处存在散射而变得复杂，该散射归因于Np - Np阳离子 - 阳离子相互作用。通过分析该峰强度随Np浓度的变化来确定二聚体配合物的稳定常数Keq = 0.74(9) M(-1)。
