Derivatives of U(BH4)4 and its Lewis base adducts; synthesis of monocyclopentadienyl- and hydride-uranium(IV) complexes: (η-C5H5)U(BH4)3 and (CH3OCH2CH2OCH3)U(BH4)3H
作者:Denise Baudry、Michel Ephritikhine
DOI:10.1016/0022-328x(88)80443-1
日期:1988.7
In solution, (THF)2U(BH4)4 and (HMPA)2U(BH4)4 adopt a trans-configuration, whereas (Ph3PO)2U(BH4)4 exists as an equilibrium mixture of two isomers. Thermolysis of (DME)U(BH4)4 gives the corresponding uranium (IV) hydride (DME)U(BH4)3H. Reaction of U(BH4)4 with TlCp or cyclopentadiene in toluene gives CpU(BH4)3.
The uranium(IV) triflate [U(OTf)4] (1) (OTf = OSO2CF3) gives stable adducts with Lewisbases, such as [U(OTf)4(py)] (2) (py = pyridine). The crystalstructure of a solvate of [U(OTf)4(OPPh3)3] (3), which exhibits a bidentate OTf group, has been determined. Substitution of the triflate ligands of 1 with LiNEt2, Kacac (acac = MeCOCHCOMe), KCp (Cp = η-C5H5), and K2COT (COT = η-C8H8) has led to the formation
作者:Jean Claude Berthet、Michel Ephritikhine、Jean Claude Berthet、Monique Lance、Martine Nierlich
DOI:10.1039/a801936c
日期:——
The uranium(IV) triflates [U(Cp*)2(OTf)2], [U(Cp)2-(OTf)2(py)], [U(Cp)3(OTf)], [U(cot)(OTf)2(py)] and [U(OTf)4(py)] have been synthesized by protonation of amide or alkyl precursors with pyridinium triflate; the crystal structures of [U(Cp*)2(OTf)2(OH2)] and [U(Cp)3-(OTf)(CNBut)] have been determined.
Observations on the thermal decomposition of some uranium(IV) tetraalkyls
作者:Tobin J. Marks、Afif M. Seyam
DOI:10.1016/s0022-328x(00)93684-2
日期:1974.1
The thermally unstable products of the reactions 4 RLi + UCl4 (R = various alkyl groups), presumed to be uranium tetraalkyls, decompose readily at room temperature in ethereal or hydrocarbon solvents. When R contains a β-hydrogen, comparable quantities of alkane (RH) and alkene (RH-H2) are produced along with trace amounts of the dimer, RR. This result indicates that uranium alkyl compounds readily
In contrast to some earlier indications, various organo-uranium(IV) complexes of the general type Cp3UX (Cp = η5-C5H5; X = CH3, C2H5, i-C3H7, n-C4H9, t-C4H9, N(C2H5)2, and even P(C6H5)2 and NCBH3, but not BH4 or NCS) react in solution with CO under mild conditions, (viz. room temperature and atmospheric pressure of CO). The (IR, 1H NMR and NIR/VIS) spectroscopic properties of the (1:1) insertion products
与一些较早的适应症,一般的类型Cp的各种有机铀(IV)配合物3 UX(CP =η 5 -C 5 H ^ 5 ; X = CH 3,C 2 H ^ 5,IC 3 ħ 7,NC 4 H 9,tC 4 H 9,N(C 2 H 5)2,甚至P(C 6 H 5)2和NCBH 3,但不是BH 4或NCS)在温和的条件下(即室温和CO的大气压下)在溶液中与CO反应。在X =烷基或二烷基酰胺的情况下,(1:1)插入产物的(IR,1 H NMR和NIR / VIS)光谱性质分别与它们的二对乙酰基和二对氨基甲酰基复合物完全吻合。虽然卡宾η 2个-OCX配体是不愿意接受连续反应典型其它氧-碳烯系统,在溶液中单体和二聚体之间的可逆平衡(对于R = CH 3和C 2 H ^ 5)不能被排除。另一方面,二巯基酰基复合物在高于60°C的温度下表现出干净的CO吸收可逆性。