The complexation of pentavalent neptunium,Np(Ⅴ),with nitrate ion in an ionic liquid solution has been studied spectroscopically for the first time.The characteristic f-f transition absorption band of Np(Ⅴ)in the NIR...The complexation of pentavalent neptunium,Np(Ⅴ),with nitrate ion in an ionic liquid solution has been studied spectroscopically for the first time.The characteristic f-f transition absorption band of Np(Ⅴ)in the NIR region changes significantly upon the titration of nitrate ion into the solution,revealing strong complexation of Np(Ⅴ)with nitrate ion in the ionic liquid.Most notably,the absorption band of Np(Ⅴ)almost disappears when a sufficiently high concentration of nitrate ion is present in the solution.Such a rare optically“silent”species can be assigned to the 1:2 Np(Ⅴ)/nitrate complex with a centrosymmetric coordination environment where Np sits at the inversion center.展开更多
基金the financial support from the National Natural Science Foundation of China(Nos.21790372 and 21822606)Beijing Natural Science Foundation(No.JQ20041)。
文摘The complexation of pentavalent neptunium,Np(Ⅴ),with nitrate ion in an ionic liquid solution has been studied spectroscopically for the first time.The characteristic f-f transition absorption band of Np(Ⅴ)in the NIR region changes significantly upon the titration of nitrate ion into the solution,revealing strong complexation of Np(Ⅴ)with nitrate ion in the ionic liquid.Most notably,the absorption band of Np(Ⅴ)almost disappears when a sufficiently high concentration of nitrate ion is present in the solution.Such a rare optically“silent”species can be assigned to the 1:2 Np(Ⅴ)/nitrate complex with a centrosymmetric coordination environment where Np sits at the inversion center.