1223591-45-4

Upstream product

• 109-99-9 tetrahydrofuran 
• 10026-10-5 uranium(IV) chloride 

Downstream Products

• 1223591-44-3 [UCl₄(C(PSPh₂)2)(Li(THF)2)2] 

Relevant academic research and scientific papers

Uranium(IV) nucleophilic carbene complexes

The mono-, bis-, and tris-carbene uranium complexes [Li(THF) 2U(SCS)Cl3(THF)] (2a), [U(SCS)2(THF) 2] (3a), and [{Li(OEt2)}2U(SCS)3] (1) were synthesized in good yields by reactions of UCl4 and the stoichiometric amount of Li2(SCS) [(SCS)2- = [Ph 2P(=S)]2C2-]. Complex 3a was also obtained by comproportionation reaction of 1 and 0.5 molar equiv of UCl4 and further reacted with 1 molar equiv of UCl4 to give the neutral mono-carbene [U(SCS)Cl2(THF)2] (5a). Treatment of U(NEt2)4 with H2C(Ph2PS)2 in THF led to a mixture of 3a and [U(SCS)(NEt2)2] (6), while the same reaction in Et2O gave the mixed alkyl-carbene compound [U(SCS)(SCHS)(NEt2)] (7) in 85% yield. The cationic uranium carbene complex [U(SCS)(NEt2)(THF)3][BPh4] (9) was isolated in almost quantitative yield from reaction of [U(NEt2) 3][BPh4] and H2C(Ph2PS)2. Mono-carbenes 2a, 5a, and 9 were used as precursors for the synthesis of Cp and COT derivatives (Cp = C5H5, COT=C8H 8). Treatment of 2a with 1 or 2 molar equiv of TlCp gave [Tl{U(Cp)(SCS)}2(μ-Cl)3] (10) and [U(Cp) 2(SCS)] (11) in 90% and 79% yield, respectively, whereas [U(Cp*)2(SCS)] (12) (Cp* = C5Me5) was obtained only by reaction of [U(Cp*)2Cl2] and Li2(SCS). Reactions of 5a or 9 with K2COT gave [U(COT)(SCS)(THF)] (13) in 78% and 99% yield, respectively. 2a, [Li(THF)(Et 2O)U(SCS)(μ-Cl)3]2 (2b), [U(SCS) 2(py)2] · 1.5py · 0.5THF (3b · 1.5py · 0.5THF), [U(SCS){CS(Ph2PS)2}(py)] (4), 7 3 toluene, [Li(THF)2U(SCS)(NEt2)(μ-O)]2 (8), 10 3 2toluene, 11, 12, and 13 3 0.5pentane were characterized by X-ray diffraction. The crystal data revealed that, in contrast to transition metal complexes, changes in the coordination sphere of the U(IV) center have little influence on the UdC bond. This feature was explained by DFT analysis of analogous U(IV) and Zr(IV) compounds [M(SCS')Cl2(py)2] and [M(SCS')(Cp)2] [M = U, Zr; SCS' = C(H2PS)2]. Although the 5f orbitals are more radially contracted than the 6d atomic orbitals, the 5f AOs are lower in energy in uranium and can lead to greater angular overlaps in symmetry-constrained systems. As a result, the seven 5f orbitals play a "buffer" role by engaging in covalent interactions with the carbon center to stabilize the nucleophilic carbene lone pairs.

Easy access to uranium nucleophilic carbene complexes

Metathesis reactions of UCl4 with Li2C(Ph 2PS)2 in Et2O only afforded the tris-carbene complex [{Li(OEt2)}2U{C(Ph2PS) 2}3] (1), while the bis- and mono-carbene compounds [U{C(Ph2PS)2}2(THF)2] (2) and [{Li(THF)2}2U{C(Ph2PS)2}Cl 4] (3) were obtained by treatment of UCl4 with Li 2C(Ph2PS)2 in a mixture of THF and toluene. The bis-carbene complex 2 was also obtained either from the comproportionation reaction of 1 and UCl4 or protonolysis reaction of U(NEt 2)4 with H2C(Ph2PS)2 and was transformed into the mono-carbene complex [U{C(Ph2PS) 2}Cl2(THF)2] (4) by further reaction with UCl4. The utility of these complexes as precursors is illustrated by the synthesis of the biscyclopentadienyl derivative [Cp2U{C(Ph 2PS)2}] (5) by treatment of 3 with TlCp. The crystal structures of [U{C(Ph2PS)2}2(py) 2]·1.5py·0.5THF and 5·toluene are reported. The Royal Society of Chemistry 2010.