158445-95-5Relevant academic research and scientific papers
Sterically induced P-C bond cleavage: Routes to substituent-free phosphorus complexes of zirconium
Fermin, Maria C.,Ho, Jianwei,Stephan, Douglas W.
, p. 4247 - 4256 (1995)
The reaction of Cp2ZrHCl with 1 equiv of K[PH(C6H2-2,4,6-t-Bu3)] and excess KH in THF yields the dark red product [Cp2ZrH(P(C6H2-2,4,6-t-Bu 3))K(THF)2]2, 4. The complex Cp*2-Zr(PH(C6H2-2,4,6-t-Bu 3))Cl, 5, is derived from the reaction of Cp*2ZrCl2 with KPH(C6H2-2,4,6-t-Bu3). Generation of 5 via the reaction of Cp*2ZrCl2 with excess KH and phosphine results in P-C bond cleavage as evidenced by the formation of the diamagnetic species (Cp*2-Zr)2(μ-P2), 6, and the paramagnetic compound (Cp*2Zr)2(μ-P), 7. Compound 7 is the first dimetallaphosphallene to be structurally characterized. In an alternate synthetic route, reaction of 2 equiv of PH2(C6H2-2,4,6-t-Bu3) with (Cp*2Zr(N2))2(μ-N2) yields P-C bond cleavage, as the species Cp*2Zr[(PH)2], 8, is formed. Reaction of 8 with KH leads to the generation of species [Cp*2Zr(P2)][K(THF)x]2, 9, which reacts with Cp*2ZrCl2 to give 6 quantitatively. In a subsequent reaction, compound 6 undergoes reaction slowly with excess PH2(C6H2-2,4,6-t-Bu3) in the presence of KH to give compound 10. X-ray crystallographic study of 10 revealed the asymmetric unit to contain Cp*2ZrP3K(THF)1.5. This species forms an infinite polymeric structure in the solid state. The nature of the bonding in species 7, 8, and 10 has been examined via EHMO calculations. The chemistry described herein demonstrates that high steric demands may induce P-C bond cleavage, thus offering a feasible metal-mediated route to substituent-free P complexes.
