HALF-SANDWICH AND MIXED-RING URANIUM COMPLEXES

The monocyclooctatetrane uranium complex [U(COT)(I)2(THF)2] (COT=eta-C8H8; THF=tetrahydrofuran), isolated from the reaction of bis(cyclooctatetrane) uranium with iodine, is a precursor for the synthesis of the alkyl derivatives [U(COT)(CH2Ph)2i (HMPA)2], [U(COT)(CH2SiMe3)2(HMPA)] (HMPA=hexamethyl phosphorous triamide) and [U(COT)(CH2SiMe3)3] [Li(THF)3] and of the mixed-ring compounds [U(COT)(eta-C5R5)(I)] (R=H or Me). The last were used to prepare the amide and alkyl complexes [U(COT)(eta-C5H5)(N{SiMe3}2)] and [U(COT)(eta-C5Me5)?? (CH2SiMe3)].