401901-96-0Relevant academic research and scientific papers
Isolation and chemistry of tantalum(v) compounds containing two resolved 3,3′-disubstituted-1,1′-bi-2,2′-naphthoxide ligands
Weinert, Charles S.,Fanwick, Phillip E.,Rothwell, Ian P.
, p. 484 - 490 (2002)
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 showa pseudo-octahedral anion with mutually cis chloride ligands. Although NMR studies indicate that the anion of (R,R)-1 is stable in DMSO-d6, 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)-l/(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).
