676245-91-3Relevant academic research and scientific papers
Synthesis, structure, and ring-opening polymerization catalysis of zinc complexes containing amido phosphinimine ligands
Liang, Lan-Chang,Tsai, Tzung-Ling,Li, Chun-Wei,Hsu, Yu-Lin,Lee, Ting-Yu
experimental part, p. 2948 - 2957 (2011/08/05)
A series of amido phosphinimine ligands of the type [(NAr 1)-o-(Ph2P=NAr2)C6H 4]- (2a: Ar1 = 2,6-C6H 3iPr2, Ar2 = 2,6-C6H 3iPr2; 2b: Ar1 = 2,6-C6H 3iPr2, Ar2 = 2,4,6-C6H 2Me3; 2c: Ar1 = 2,6-C6H 3Me2, Ar2 = 2,4,6-C6H 2Me3), which are electronic variations of monoanionic β-diketiminates, have been employed to examine the coordination chemistry of zinc. Alkane elimination reactions of ZnR2 (R = Me, Et) with H[2a-c] in toluene or ethereal solutions at -35 °C afforded cleanly the corresponding organozinc complexes [2a-c]ZnMe (3a-c) and [2a-c]ZnEt (4a-c). Deprotonation of H[2a-c] with nBuLi at -35 °C generated [2a-c]Li (5a-c), which may be isolated as either solvent-free complexes or solvated adducts depending on the reaction solvents employed (toluene, OEt2, or THF). Metathetical reactions of 5a·OEt2 with Zn(OAc)2 in THF at -35 °C produced [2a]Zn(OAc) (6a). These amido phosphinimine derivatives all display solution Cs symmetry on the NMR timescale. The mononuclear nature of the three-coordinate alkyls 3-4 and four-coordinate acetate 6a was confirmed by single-crystal X-ray diffraction analyses. Interestingly, the alkyl complexes 3a-c and 4a-c are all active initiators for the catalytic ring-opening polymerization of Iμ-caprolactone, whereas the acetate 6a is comparatively inactive. Copyright
