The first mixed cyclooctatetraenyl-phospholyl metal complexes. Crystal structure of [U(η-C8H8)(η-C4Me4P)(BH4)(OC4H8)]

Treatment of [U(COT)(BH4)2(THF)] (1) or [U(COT)(BH4)(THF)2][BPh4] (2) (COT=η-C8H8) with Ktmp (tmp, η-C4Me4P) gave [U(COT)(tmp)(BH4)(THF)] (4), the crystal structure of which was determined. Further reaction of Ktmp with 4 afforded the ‘ate’ addition derivative K[U(COT)(tmp)2(BH4)(THF)x]. Complex 4 was transformed into [U(COT)(tmp)(OEt)] (5) in the presence of NaOEt. The cationic compound [U(COT)(tmp)(HMPA)2][BPh4] (6) (HMPA, hexamethylphosphoramide) was isolated from the reaction of [U(COT)(HMPA)3][BPh4]2 (3) with Ktmp. The cationic complexes 2 and 3 were recovered upon protonation of 4 and 6 with NEt3HBPh4.