Highly Efficient Separation of Trivalent Minor Actinides by a Layered Metal Sulfide (KInSn2S6) from Acidic Radioactive Waste.

The elimination of trivalent minor actinides (Am3+, Cm3+) is of great concern for the safe management and operation of nuclear waste geological repository and environmental remediation. However, because of the effects of protonation, most of the present sorbents exhibit inferior removal properties toward minor actinides at low pH values. Finding stable ion-exchangers with high sorption capacities, fast kinetics, and good removal toward minor actinides from highly acidic solution remains a great challenge. This work reports a new family member of KMS materials with a robust acid-stable layered metal sulfide structure (KInSn2S6, KMS-5) bearing strong affinity toward trivalent minor actinides. KMS-5 can simultaneously separate trivalent 241Am and 152Eu from acidic solutions below pH 2 with high efficiency (>98%). The ion-exchange kinetics is extremely fast (<10 min) and the largest distribution coefficient is as high as 5.91 × 104 mL/g. KMS-5 is also capable of efficiently removing 241Am from acidic solution containing various competitive cations in large excess. In addition, the ion exchange process of 241Am by KMS-5 is reversible and the loaded material can be easily eluted by high concentration of potassium chloride. This work represents the first case for efficient minor actinides removal from highly acidic solution using layered metal sulfide materials.

Organotin chalcogenide salts: synthesis, characterization, and extended crystal structures.

Reactions of Cl(3)SnR(1)H with Na(2)E (E = Se, Te; R(1) = C(2)H(4)COO) in liquid ammonia afforded the salts of an anionic defect heterocubane, [(RSn)(3)Se(4)](-) (R = R(1) and R(1)H) or an (infinity)(1)[(R(1)Sn)(2)Te(3)(2-)] anionic polymer, respectively. Although a reaction using a 1:1.5 ratio of Cl(3)SnR(1)H:Na(2)S.(9)H(2)O in acetone/water produced a compound containing [(R(1)Sn)(3)S(4)](2-), a 1:2 ratio leads to the formation of (infinity)(1)[(R(1)Sn)(2)S(3)(2-)], isostructural to the homologous Te species.

Facile access to the hydrazone functionalized PdGeS cluster [{R(N)Ge(mu-S)3}4Pd6] from the thiogermanate anion [{R(N)Ge}2(mu-S)2S2]2-.

The decanuclear ternary PdGeS cluster [{R(N)Ge(mu-S)(3)}(4)Pd(6)] x MeOH (2 x MeOH) has been obtained in high yield by a two-step reaction, involving the derivatization of the carbonyl functionalized adamantane-like [(R(1)Ge)(4)(mu-S)(6)] (R(1) = CMe(2)CH(2)COMe) with N(2)H(4) x H(2)O, and a subsequent reaction of the resulting hydrazone functionalized thiogermanate (NH(3)NH(2))(2)[(R(N)Ge)(2)(mu-S)(2)S(2)] (R(N) = CMe(2)CH(2)CMeNNH(2), 1) with an acidic solution of (N,N'-tmeda)Pd(NO(3))(2). Cluster 2 has an elegant molecular structure which can be viewed as an R(N) ligated ensemble of four edge-sharing [Pd(3)GeS(3)] defect hetercubanes that meet at an unoccupied center. Thus, the cluster consists of six square-planar coordinated Pd(II) ions at the vertices of a regular octahedron with four faces capped by four [R(N)GeS(3)](3-) units. The title compounds were structurally characterized by means of single-crystal X-ray diffraction as well as physical property measurements. Moreover, density functional theory calculations were performed to gain insight into the unique coordination situation of the hydrazone substituent.

Thiostannate tin-tin bond formation in solution: in situ generation of the mixed-valent, functionalized complex [{(RSn(IV))2(mu-S)2}3Sn(III)2S6].

In broad daylight: The double-decker thiostannate [(RSn(IV))(4)S(6)] (1, R = CMe(2)CH(2)COMe) condenses to form [{(RSn(IV))(2)(mu-S)(2)}(3)Sn(III)(2)S(6)] (2; see picture). This mixed-valent complex, which formally contains both Sn(III) and Sn(IV) atoms as confirmed by Mössbauer spectroscopy and DFT calculations, forms by a complicated, concerted mechanism. Additionally, 2 provides six carbonyl groups for further derivatization.