502966-89-4Relevant academic research and scientific papers
Synthesis and characterization of some zirconium and hafnium complexes with a phosphide-pendant cyclopentadienyl ligand
Ishiyama, Takeshi,Mizuta, Tsutomu,Miyoshi, Katsuhiko,Nakazawa, Hiroshi
, p. 1096 - 1105 (2008/10/08)
Synthesis of some Zr and Hf complexes with a phosphide-pendant cyclopentadienyl ligand was attempted via alkylation (tribenzylation, triallylation, or monotritylation) of the secondary phosphine-pendant trichloride complex [{η5-C5H4(CH2)2P(H)Me s-κP}MCl3(tht)] (Zr-1, Hf-1; Mes = 2,4,6-trimethylphenyl; tht = tetrahydrothiophene). The phosphide-pendant dibenzyl complex [{η5-C5H4(CH2)2PMes- κP}M(CH2Ph)2] (Zr-5, Hf-5) and the phosphidependant diallyl complex [{η5-C5H4(CH2)2PMes- κP}M(allyl)2] (Zr-7, Hf-7) were successfully prepared through tribenzylation followed by thermolysis and through triallylation, respectively, of Zr-1 or Hf-1. The phosphide-pendant dichloride complex [{η5-C5H4(CH2)2PMes κP}MCl2(N-methylimidazole)2] (Zr-13, Hf-13) was also obtained through monotritylation of Zr-1 or Hf-1 followed by the treatment with N-methylimidazole, and the X-ray crystal structure of Zr-13 was determined. In addition, the allyl-chloride exchange reaction between 1 equiv of Hf-1 and 2 equiv of Hf-7 gave the unstable phosphide-pendant monoallyl monochloride Hf complex [{η5-C5H4(CH2)2PMes- κP}HfCl(allyl)] (Hf-8), which was characterized as its derivatives [{η5-C5H4(CH2)2PMes- κP}Hf(f)(allyl)] (Y = C6F5, Hf-14; Y = NPh2, Hf-15; Y = NEt2, Hf-16). It is proposed that the η3-alkyl-like ligand (benzyl, allyl, or trityl) in the secondary phosphine-pendant complex serves as an effective H-abstracting group to generate the corresponding phosphide-pendant complex with liberation of the alkyl-H coupling product.
