Cooperative Rare-Earth/Lithium-Mediated Conversion of White Phosphorus.

Abstract

The rare-earth/lithium cooperative effect on functionalization of white phosphorus has been investigated. The reaction of diazabutadiene-supported yttrium hydride chelated a LiPPh2 molecule (LY ⋅ THF)2 (μ-H)2 [μ-PPh2 (Li)] (1, L=N,N'-di(2,6-diisopropylphenyl)-1,4-diazabutadiene) with P4 gave two novel mixed Y/Li multinuclear polyphosphorus complexes (LY ⋅ THF)2 [cyclo-P3 ]Li(THF)3 (2) and [Li(THF)4 ]+ [(LY ⋅ THF)3 (norborane-P7 )Li(THF)]- (3), accompanied with the elimination of diphosphorus compound Ph2 PPPh2 (4) and H2 . However, the comparative reaction of yttrium hydride (LY ⋅ THF)2 (μ-H)2 with P4 afforded a trinuclear yttrium pyramid-P4 complex (LY ⋅ THF)3 (μ3 -P(PH)3 ) (5). Further investigations show that 5 cannot continuously react with LiPPh2 to form 2 and 3, and LiPPh2 reacted with P4 to form a Zintl-P7 lithium complex (TMEDA⋅Li)3 (Zintl-P7 ) (6) and 4. These results indicated that the cooperation of Y/Li for activation of P4 is a key for the formation of 2 and 3. All new compounds have been characterized by NMR spectroscopy and single-crystal X-ray diffraction studies.