Synthesis and Structure of a Discrete Hexanuclear Uranium–Phosphate Complex

Abstract

COMMUNICATIONS spectroscopy. The low g value (2.00374) and the coupling constants (u,,,, = 0.338 mT, uHm = 0.133 mT, aN = 0.802 mT), which are typical of aminyl radicals, enabled the presence of a nitroxyl radical to be ruled out.[''] The diradical 17 ( g = 2.00374) prepared by dehydrogenation of the model compound 11 could be confirmed by ESR spectroscopy. Zero field splitting at 135 K (toluene, glass) was determined to be 1.76 mT. The distance of 1.1 7 nm found from this by point dipole estimation is in good agreement with the calculated distance between the aminyl centers of I .O2 nm. [191 17 The new polymer PPSA has a well-defined structure and a high molecular weight. It is colorless, stable at temperatures up to 380 'C, very soluble in many common organic solvents, and dopable. Continuing investigations into its optical and electronic properties and into the conversion of 1 into the polyradical 15 are in progress.

First Hexanuclear UIV and ThIV Formate Complexes – Structure and Stability Range in Aqueous Solution

“…However, the deviations of the µ 3 -oxygen groups from the M 3 plane are averaged, indicating a delocalization of µ 3 -O/µ 3 -OH. [7,14] In the other previous studies, all µ 3 -oxygen atoms showed a uniform deviation of approx. 0.6-0.8 Å from the M 3 plane and were regarded as equivalent oxido groups.…”

“…The arrangements of M in these hexanuclear skeletons (Figure 1, bottom) are similar to those in other reported [U 6 (µ 3 -O) 8 ] complexes. [7][8][9][10][11][12][13][14] Actually, the {µ 3 -O(H)} 8 hexahedra in 1-3 are very distorted, whereas those of the previously reported [U 6 (µ 3 -O) 8 ] complexes are regularly hexahedral. This distortion in 1-3 arises from the presence of two kinds of µ 3 -oxygen atoms, which have different deviations from a plane defined by three neighboring M atoms (M 3 plane, Figure S1 in the Supporting Information): 0.35 and 1.06 Å (Table S1).…”

Self‐Assembly of Polyoxo Clusters and Extended Frameworks by Controlled Hydrolysis of Low‐Valent Uranium

“…X-ray analysis revealed the presence of three additional species with different structures, namely the 3D {[U 6 (m 3 -O) 8 (m 2 -OTf) 12 3 ] [29] in the hydrolysis reaction, the formation of a cluster with nuclearity larger than six is not observed, and mixtures of compounds 2, 3, and 4 are isolated even after a month. This outlines the important role of the ligands in directing the cluster formation.…”

“…[16,17] In particular, it is surprising that since the first report of a uranium cluster containing an isopolyoxometalate U 6 O 8 core in 1952 [18] only three additional examples of well-characterized uranium oxo clusters-all hexanuclear-have been described. [10][11][12] This contrasts dramatically with the extensive structural variety of transitionmetal polyoxometalate compounds [19][20][21] despite the similarity of the chemical properties of uranium with respect to Mo and W.…”

“…In the discrete hexametallic compound [U 6 (m 3 -O) 8 (m 2 -OTf) 12 In the second type of isolated crystals, the U 6 O 8 octahedrons are arranged in a 3D network with the formula {[U 6 (m 3 -O) 8 (m 2 -OTf) 12 …”