Uranium trimethylsilyl cyclopentadienyl

A solution of [f/ -l,3-bis(trimethylsilyl)cyclopentadienyl]lithium is prepared in situ, using the procedure described in Section 33.A, from butyllithium (IS.OmL of a 1.5 M solution in C6H14, 29 mmol) and bis(trimethylsilyl)cyclo-pentadiene (5.89g, 28 mmol) in THF (lOOmL). This solution is added dropwise during h to a stirred, cooled (0°Q solution of uranium(IV) chloride (5.45g, 14mmol) in THF (lOOmL). The mixture is stirred at 25°C for 12h. Removal of the solvent at 25 °C and lOtorr affords a sticky brown residue this residue is warmed to 60°C at 10 torr. The brown involatile solid is extracted into warm toluene (100 mL), and the extract is filtered. The brown filtrate is concentrated (to 50mL), then cooled to — 30°C to yield large orange-brown crystals of [UCp"2 CI2 ] (2). Yield 6.1 g (60%). Two further crops of crystals are obtained from the mother liquor (total yield, 90%). For its characterization, see Table I. 

Cl Si2ThC2jH42, Thorium(lV), bis(-n -l,3-bi (trimethylsilyl)-cyclopentadi-enyl]dichloro-, 27 173 CI,Si2UC22H42, Uranium(IV), bis(tt -l,3-bis(trimethylsilyl)- cyclopentadienyl]-dichloro-, 27 174... 

I,N PtCftHij, Platinum(II), [irans-(/f,/t)-l,2-cyclohexanediamine]diiodo-, 27 284 IjSi.UCaHj , Uranium(IV), bis[T] -l,3-bis(trimethylsilyl)cyclopentadienyl]-diiodo-, 27 176... 

Si2BrjUC.jH4j, Uranium(IV), bis((V-1.3-bis(trimethylsilyl)cyclopentadienyl)-dibromo-, 27 174... 

Ul2Si,C22H42, Uranium(IV), bis[(n -l,3-bis-(trimethylsilyl)cyclopentadienyl]-diiodo-, 27 176... 

SiOCgHjg, Silane, methoxytrimethyl-, 26 44 SiPC2iH39, Phosphine, (2,4,6-tri-tert-butylphenyl)(trimethylsilyl)-, 27 238 Si2Br2UC22H42, Uranium(IV), bis( t -l,3-bis(tnmethylsilyl)cyclopentadienyl]di-bromo-, 27 174... 

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