The [U₂F₁₂]²⁻ Anion of Sr[U₂F₁₂]

Abstract

The D 2h -symmetric dinuclear complex anion [U 2 F 12 ] 2À of pastel green Sr[U 2 F 12 ]s hows ah itherto unknown structural feature:T he coordination polyhedra around the U atoms are edge-linked monocapped trigonal prisms,t he U V atoms are therefore seven-coordinated. This leads to aU -U distance of 3.8913(6) .Aweak U V -U V interaction is observed for the dinuclear [U 2 F 12 ] 2À complex and described by the antiferromagnetic exchange J exp of circa À29.9 cm À1 .T he crystalline compound can be easily prepared from SrF 2 and b-UF 5 in anhydrous hydrogen fluoride (aHF) at room temperature.I tw as studied by means of single crystal X-ray diffraction, IR, Raman and UV/VIS spectroscopy, magnetic measurements,a nd by molecular as well as by solid-state quantum chemical calculations.

Reactions of ClF3 with Main Group and Transition Metal Oxides: Access to Dioxychloronium(V) Fluoridometallates and Oxidofluoridometallates

“…For actinide pentafluorides no anions of the form [ M n F 5n+1 ] − ( n =2, 3, 4) have been reported as of yet, and these pentafluorides might differ in their reactivity and structural chemistry from main group and transition metal pentafluorides due to the higher possible coordination number for the central atom [96] . For example, in the compound Sr[U 2 F 12 ], the [U 2 F 12 ] 2− anion may be described as two condensed [UF 6 ] − anions, resulting in coordination number seven for the U atoms [97] …”

“…[96] For example, in the compound Sr[U 2 F 12 ], the [U 2 F 12 ] 2À anion may be described as two condensed [UF 6 ] À anions, resulting in coordination number seven for the U atoms. [97] The best-studied AF/MF 5 system is probably that of SbF 5 , for which crystal structures of compounds containing all abovementioned anions have been described. [94,[98][99][100] [94,98,100] The only example of a trans-bridging central [SbF 6 ] polyhedron seems to be Br 2 [Sb 3 F 16 ].…”

Strontium Nitridoborate Hydride Sr2BN2H Verified by Single-Crystal X-ray and Neutron Powder Diffraction

“…36,37 The basis sets for Sr, N, B, and H were previously derived from the Karlsruhe def2 basis sets. 38 Triple valence polarized basis sets were used for N, B, and H 24,39 and the split valence basis set for Sr. 39,40 The reciprocal space was sampled using a Monkhorst-type 3 × 8 × 4 k-mesh. 41 Tightened tolerance factors (TOLINTEG) of 8, 8, 8, 8, and 16 were used for the evaluation of the exchange and Coulomb integrals.…”

A Revised Structure Model for the UCl6 Structure Type, Novel Modifications of UCl6 and UBr5, and a Comment on the Modifications of Protactinium Pentabromides

“…The intermolecular U−U distances are above 6.2 Å, whereas the intramolecular U−U distances of the two distinct U 2 Br 10 molecules are much shorter (4.3003(3) and 4.2962(4) Å). These U−U distances are longer compared to Sr[U 2 F 12 ] with 3.8913(10) Å, as well as α‐ and β‐UCl 5 with circa 4.17 Å, but shorter compared to α‐UF 5 (ca. 4.5 Å) and β‐UF 5 (4.5 and 4.6 Å) with different coordination polyhedra .…”