Doped Semimetal Clusters: Ternary, Intermetalloid Anions [Ln@Sn₇Bi₇]^4– and [Ln@Sn₄Bi₉]^4– (Ln = La, Ce) with Adjustable Magnetic Properties

Abstract

Two K([2.2.2]crypt) salts of lanthanide-doped semimetal clusters were prepared, both of which contain at the same time two types of ternary intermetalloid anions, [Ln@Sn(7)Bi(7)](4-) and [Ln@Sn(4)Bi(9)](4-), in 0.70:0.30 (Ln = La) or 0.39:0.61 (Ln = Ce) ratios. The cluster shells represent nondeltahedral, fullerane-type arrangements of 14 or 13 main group metal atoms that embed the Ln(3+) cations. The assignment of formal +III oxidation states for the Ln sites was confirmed by means of magnetic measurements that reveal a diamagnetic La(III) compound and a paramagnetic Ce(III) analogue. Whereas the cluster anions with a 14-atomic main-group metal cage represent the second examples in addition to a related Eu(II) cluster published just recently, the 13-atomic cages exhibit a yet unprecedented enneahedral topology. In contrast to the larger cages, which accord to the Zintl-Klemm-Busmann electron number-structure correlation, the smaller clusters require a more profound interpretation of the bonding situation. Quantum chemical investigations served to shed light on these unusual complexes and showed significant narrowing of the HOMO-LUMO gap upon incorporation of Ce(3+) within the semimetal cages.

[Bi12Ni7(CO)4]4–: Aggregation of Intermetalloid Clusters by Their Thermal Deligation and Oxidation

“…One approach is to aggregate the known smaller Bi/Ni/CO clusters Bi 3 Ni 4 (CO) 6 3− , Bi 3 Ni 6 (CO) 9 3− , and Ni@Bi 6 Ni 6 (CO) 8 4− by applying oxidation and deligation. Both processes can be accomplished by simply elevating the temperature of the reaction mixture.…”

Recent Advances in Rare‐Earth Polypnictides

“…The figures in B) and C) were reprinted from Ref. . The figures in D) and E) were reprinted from Ref.…”

“…On the contrary, when larger La 3+ or Ce 3+ cations were treated with [Sn 2 Bi 2 ] 2– precursors, two new classes of ternary clusters, namely [Ln@Sn 7 Bi 7 ] 4– (Figure B) and [Ln@Sn 4 Bi 9 ] 4– (Figure C), were obtained . The former 14‐vertex [Ln@Sn 7 Bi 7 ] 4– cluster consists of three square faces and five pentagons, while the latter 13‐vertex [Ln@Sn 4 Bi 9 ] 4– is made up of five square faces and four pentagons.…”

Extending DFT-based genetic algorithms by atom-to-place re-assignment via perturbation theory: A systematic and unbiased approach to structures of mixed-metallic clusters

“…Also for this species a promising candidate for the global minimum exists; it can be derived from the homologue system [LaSn 7 Bi 7 ] 4− , for which in a combined experimental and computational study 22 the structure (via X-ray diffraction) and the atom type assignment (via explicit calculation of isomers) were determined. The topology of [LaSn 7 Bi 7 ] 4− is of approximate D 3h symmetry and may be described as consisting of a central layer (A) with La in the middle surrounded by six atoms, two threeatomic layers (B, B ) above and below A and two single atoms above/below layers B/B .…”