The chemistry of uranium. Part 35. Synthesis and characterization of UI4L2 complexes (L = bulky amide ligands) and the crystal structure of UI4tmu2 (tmu = tetramethylurea)

Preez, J. G. H. Du; Zeelie, Ben; Casellato, U.; Graziani, R.

doi:10.1016/s0020-1693(00)86677-3

Cited by 27 publications

(38 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For example for uranium in oxidation state +III, the U-I bond lengths in UI 3 (THF) 4 are 3.119, 3.166, and 3.103 Å 21 which are slightly longer than those observed for 3 and 4, where uranium is in the +VI oxidation state. For uranium in the +IV oxidation state, both neutral compounds (e.g., UI 4 (OC- (NMe 2 ) 2 ) 4 ) 22 and anionic species (e.g., (Ph 4 P) 2 UI 6 ) 23 have been reported. The bond lengths reported for UI 4 (OC-(NMe 2 ) 2 ) 4 (d(U-I) ) 3.027 and 2.997 Å) 22 and (Ph 4 P) 2 UI 6 (d(U-I) ) 2.986, 3.001, and 3.005 Å) 23 (where uranium is in the +IV oxidation state) compare well with those of 3, 4, and 6, where uranium is in the +VI oxidation state (d(U-I) ) 3.0267 (6) ) 2.30(1) Å).…”

Section: Resultsmentioning

confidence: 99%

“…For uranium in the +IV oxidation state, both neutral compounds (e.g., UI 4 (OC- (NMe 2 ) 2 ) 4 ) 22 and anionic species (e.g., (Ph 4 P) 2 UI 6 ) 23 have been reported. The bond lengths reported for UI 4 (OC-(NMe 2 ) 2 ) 4 (d(U-I) ) 3.027 and 2.997 Å) 22 and (Ph 4 P) 2 UI 6 (d(U-I) ) 2.986, 3.001, and 3.005 Å) 23 (where uranium is in the +IV oxidation state) compare well with those of 3, 4, and 6, where uranium is in the +VI oxidation state (d(U-I) ) 3.0267 (6) ) 2.30(1) Å). 5d The use of OP(NMe 2 ) 3 as a coordinating ligand has resulted in the high yield, gram-scale synthesis of a non-air-sensitive U VI -I compound which is soluble in various organic solvents, may be a useful new starting material, and does not require the use of difficult to prepare or air-sensitive starting materials, or even anhydrous conditions.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and Characterization of Heavier Dioxouranium(VI) Dihalides

et al. 2004

View full text Add to dashboard Cite

The synthesis and characterization of the dioxouranium(VI) dibromide and iodide hydrates, UO(2)Br(2)x3H(2)O (1), [UO(2)Br(2)(OH(2))(2)](2) (2), and UO(2)I(2)x2H(2)Ox4Et(2)O (3), are reported. Moreover, adducts of UO(2)I(2) and UO(2)Br(2) with large, bulky OP(NMe(2))(3) and OPPh(3) ligands such as UO(2)I(2)(OP(NMe(2))(3))(2) (4), UO(2)Br(2)(OP(NMe(2))(3))(2) (5), and UO(2)I(2)(OPPh(3))(2)(6) are discussed. The structures of the following compounds were determined using single-crystal X-ray diffraction techniques: (1) monoclinic, P2(1)/c, a = 9.7376(8) A, b = 6.5471(5) A, c = 12.817(1) A, beta = 94.104(1) degrees , V = 815.0(1) A(3), Z = 4; (2) monoclinic, P2(1)/c, a = 6.0568(7) A, b = 10.5117(9) A, c = 10.362(1) A, beta = 99.62(1) degrees , V = 650.5(1) A(3), Z = 2; (4) tetragonal, P4(1)2(1)2, a = 10.6519(3) A, b = 10.6519(3) A, c = 24.0758(6) A, V = 2731.7(1) A(3), Z = 4; (5) tetragonal, P4(1)2(1)2, a = 10.4645(1) A, b = 10.4645(1) A, c = 23.7805(3) A, V = 2604.10(5) A(3), Z = 4, and (6) monoclinic, P2(1)/c, a = 9.6543(1) A, b = 18.8968(3) A, c = 10.9042(2) A, beta =115.2134(5) degrees , V = 1783.01(5) A(3), Z = 2. Whereas 1 and 2 are the first UO(2)Br(2) hydrates and the last missing members of the UO(2)X(2) hydrate (X = Cl --> I) series to be structurally characterized, 4 and 6 contain room-temperature stable U(VI)-I bonds with 4 being the first structurally characterized room temperature stable U(VI)-I compound which can be conveniently prepared on a gram scale in quantitative yield. The synthesis and characterization of 5 using an analogous halogen exchange reaction to that used for the preparation of 4 is also reported.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of Heavier Dioxouranium(VI) Dihalides

et al. 2004

View full text Add to dashboard Cite

show abstract

“…However, the coordination number of the uranium atom in some other compounds containing larger atoms than oxygen may be six or seven [4,5]. The diversity of these compounds is related to the ratio of the acceptor and donor capacities of uranium and the ligands, as well as to the peculiarities of the structures that are formed.…”

Section: Introductionmentioning

confidence: 99%

“…The coordination number of the U 4+ ion in chloride and bromide complexes with electron donor ligands may be 6 or 8 [21][22][23][24]. if the coordination number equals 6, then the symmetry of the surroundings of the U 4+ ion is re- In UCl 4 ⋅2DMSO, where the symmetry of the surroundings of U 4+ is close to D 4h (see Fig.…”

Section: Introductionmentioning

confidence: 99%

Electronic spectra of uranium tetrachloride clusters with electron-donor ligands

et al. 2009

View full text Add to dashboard Cite

Electronic absorption spectra of nanoclusters of uranium tetrachloride are obtained experimentally and analyzed over a wide spectral range, from the visible to the IR. The structure of the long wavelength electronic absorption spectra is discussed in terms of the structure and electron-donor number of the attached ligand. Molecules of dimethyl sulfoxide (DMSO), hexamethyl phosphotriamide (HMPT), and water were used as ligands. The effect of the symmetry of the surroundings of the U 4+ ion on the structure of the electronic spectrum is examined.

show abstract

“…Despite the fact that the donor number of DMSO is more than twice that of water, the latter is not completely removed from the nearest-neighbor coordination sphere. If we assume that in the indicated compound, the uranium atom preserves its hexa coordination and is found almost at the center of a slightly distorted octahedron, then in analogy with the bromide and iodide of U 4+ [6,7], four chlorine atoms will be found in the plane of the octahedron with the uranium atom at the center, while two DMSO or water molecules will be found at the vertices of the octahedron, along the vertical (at distances of 0.24-0.26 nm).…”

mentioning

confidence: 99%