Isolation and Chemistry of Tantalum(V) Compounds Containing Two Resolved 3,3‘-Disubstituted-1,1‘-bi-2,2‘-Naphthoxide Ligands
Reaction of dimeric [(Et2N)2Cl2Ta(μ-Cl)2TaCl2(NEt2)2] with (R)-[H2O2C20H10(R)2-3,3‘] (R = SiMe3, SiMe2Ph, SiMePh2, or SiPh3) produces the 3,3‘-dialkyl-1,1‘-bi-2,2‘-naphthoxido complexes (R,R)-[H2NEt2][Ta(O2C20H10{R}2-3,3‘)2Cl2] (R = SiMe3, (R,R)-1; SiMe2Ph, (R,R)-2; SiMePh2, (R,R)-3; SiPh3, (R,R)-4)...
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Published in | Organometallics Vol. 21; no. 3; pp. 484 - 490 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
04.02.2002
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | Reaction of dimeric [(Et2N)2Cl2Ta(μ-Cl)2TaCl2(NEt2)2] with (R)-[H2O2C20H10(R)2-3,3‘] (R = SiMe3, SiMe2Ph, SiMePh2, or SiPh3) produces the 3,3‘-dialkyl-1,1‘-bi-2,2‘-naphthoxido complexes (R,R)-[H2NEt2][Ta(O2C20H10{R}2-3,3‘)2Cl2] (R = SiMe3, (R,R)-1; SiMe2Ph, (R,R)-2; SiMePh2, (R,R)-3; SiPh3, (R,R)-4). Structural studies of the SiMe3 derivative (R,R)-1 show a pseudo-octahedral anion with mutually cis chloride ligands. Although NMR studies indicate that the anion of (R,R)-1 is stable in DMSO-d 6, an equilibrium mixture is observed in C6D6 solution with the neutral complex (R,R)-[Ta{O2C20H10(SiMe3)2-3,3‘}2Cl], (R,R)-1a, and [H2NEt2]Cl. The temperature dependence of the equilibrium has been studied. Addition of [nBu4N]Cl to a mixture of (R,R)-1/(R,R)-1a in C6D6 is shown (1H NMR) to shift the equilibrium toward (R,R)-1. Alkylation of (R,R)-1 with Grignard reagents RMgCl results in formation of the five-coordinate (R,R)-[Ta(O2C20H10{SiMe3}2-3,3‘}2R‘] (R‘ = CH2SiMe3, (R,R)-5; CH2Ph, (R,R)-6; c-C5H9, (R,R)-7). |
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Bibliography: | ark:/67375/TPS-ZK6BC2WB-4 istex:A0A3469292A74F87D6F366BFAC1CEE8D2006BF98 |
ISSN: | 0276-7333 1520-6041 |
DOI: | 10.1021/om0108200 |