Synthesis of zirconium complexes containing the tridentate diamido ligands [(t-Bu-d{sub 6}-N-o-C{sub 6}H{sub 4}){sub 2}S]{sup 2{minus}} and [(i-PrN-o-C{sub 6}H{sub 4}){sub 2}S]{sup 2{minus}}
- Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemistry
The thioethers (t-Bu-d{sub 6}-NH-o-C{sub 6}H{sub 4}){sub 2}S (H{sub 2}[t-BuNSN]) and (i-PrNH-o-C{sub 6}H{sub 4}){sub 2}S (H{sub 2}[i-PrNSN]) have been prepared in three steps in good yield. Zirconium complexes that contain the [t-BuNSN]{sup 2{minus}} ligand ([T-BuNSN]Zr(NMe{sub 2}){sub 2}, [t-BuNSN]ZrCl{sub 2}, and [t-BuNSN]ZrMe{sub 2}) were prepared readily, but the last is unstable, and no higher alkyl homologues could be prepared. In contrast, [i-PrNSN]ZrMe{sub 2} and [i-PrNSN]Zr(CH{sub 2}CHMe{sub 2}){sub 2} are both stable, even at elevated temperatures. An X-ray study of [t-BuNSN]ZrCl(NMe{sub 2}) showed it to have a geometry about zirconium that is approximately trigonal bipyramidal with the chloride and sulfur atoms in the axial positions. An X-ray study of [i-PrNSN]ZrMe{sub 2} showed it to have approximately a square-pyramidal structure with a methyl group in the apical position. Low-temperature solution {sup 1}H and {sup 13}C NMR spectra of [t-BuNSN]{sup 2{minus}} and [i-PrNSN]{sup 2{minus}} species are consistent with the solid-state structures, although inversion at sulfur on the NMR time scale results in equilibration of the two metal substituents (e.g., methyl groups). Cationic complexes prepared from [RNSN]ZrMe{sup 2} precursors (R = t-Bu, i-Pr) were neither stable at 22 C nor active for the controlled polymerization of 1-hexene.
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States); Alexander von Humboldt-Stiftung, Bonn (Germany)
- DOE Contract Number:
- FG02-86ER13564
- OSTI ID:
- 338547
- Journal Information:
- Organometallics, Vol. 18, Issue 5; Other Information: PBD: 1 Mar 1999
- Country of Publication:
- United States
- Language:
- English
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