Tetramethylphospholyluranium complexes and their pentamethylcyclopentadienyl analogues

A Comparison of Analogous 4f‐ and 5f‐Element Compounds: Syntheses and X‐ray Crystal Structures of the Mixed Sandwich Complexes [M(η‐C8H8)(L){OP(NMe2)3}] (M = Nd or U; L = η‐C5Me5 or η‐C4Me4P)

“…[19] In the crystal structure of 3, the NdϪtmp(centroid) distance of 2.59(1) Å compares well with the corresponding value of 2.57 Å in [Nd(COT)(Dsp)(THF)]; [14] the NdϪP bond length is equal to 3.0195(4) Å in the latter and to 2.968(8) Å in 3. As previously observed in other analogous tmp and Cp* compounds, [12] the NdϪtmp(centroid) distance in 3 is longer, by 0.1 Å , than the NdϪCp*(centroid) distance in 1b. The NdϪO distances in 1b and 3, 2.441 (3) [7] while the NdϪC(COT) distances are practically the same.…”

“…[6] (2), which was obtained as a green powder in 75% yield. Considering that the Nd(COT)(Cp*) species was isolated as the THF adduct [Nd(COT)(Cp*)(THF)], it is very likely that the isosteric moiety Nd(COT)(tmp), which is less electron-rich because the tmp group is less electron-donating than the Cp* ligand, [12] adopts in the solid state a dimeric structure ensured by a µ-η 5 ,η 1 -bridging tmp ligand. The ability of the phospholyl ligand to bridge two metal centers through the available lone pair on the P atom is well documented, and can be illustrated with the structures of the U III complexes [U(tmp) 2 [7] Complex 5 is the first mixed cyclooctatetraenyl/ phospholyl complex of uranium().…”

Heterocyclopentadienyl Complexes of Group-3 Metals

“…Mono-or bis(phospholyl)U IV complexes such as [(η 5 -Tmp)UCl 3 (DME)] [22] (16), [(η 5 -Tmp) 2 UCl 2 ], [22] [(η 5 -Tmp) 2 U(BH 4 ) 2 ] [23] (17), and [(η 5 -Tmp)U(BH 4 ) 3 ] [24] could be prepared by reaction of UCl 4 or U(BH 4 ) 4 with KTmp. A mixed Tmp/Cp* complex, [(η 5 -Tmp)(η 5 -Cp*)U(BH 4 ) 2 ], [22,25] could also be obtained from KTmp and [(η 5 -Cp*)U(BH 4 ) 3 ]. These Tmp complexes could, in turn, be converted into [(η 5 -Tmp)UX 3 (DME)], [(η 5 -Tmp)(η 5 -Cp*)UX 2 ], and [(η 5 -Tmp) 2 UX 2 ] (X ϭ alkyl, alkoxy) by reaction with the appropriate nucleophiles.…”

Uranocene. The First Member of a New Class of Organometallic Derivatives of the f Elements

“…Mono-and bis(tetramethylphospholyl) complexes of uranium also were prepared. 102 In addition to studies of the chemistry of cyclopentadienyluranium complexes, Ephritikhine and co-workers have reported interesting new types of organouranium compounds.…”