577700-85-7Relevant articles and documents
The isolation and chemistry of tantalum dimethylamides containing resolved 3,3′-disubstituted-1,1′-bi-2,2′-naphthoxide ligands
Son, Au Ji Ru,Schweiger, Scott W.,Thorn, Matthew G.,Moses, John E.,Fanwick, Phillip E.,Rothwell, Ian P.
, p. 1620 - 1627 (2007/10/03)
Reaction of the tantalum dimethylamide substrates [Ta(NMe2) 5] or mer,cis-[Ta(NMe2)2Cl 3(HNMe2)] with one equivalent of the 3,3′- disubstituted-2,2′-dihydroxy-1,1′-binaphthyl [H2O 2C20H10(R)2-3,3′] (R = SiMe3, 1; SiMe2Ph, 2; SiMePh2, 3; SiPh 3,4) leads to the series of amine adducts [Ta(O2C 20H10R2-3,3′)(NHMe2)(NMe 2)3] (R = SiMe3, 5; SiMe2Ph, 6; SiMePh2) 7; SiPh3, 8) and [Ta(O2C 20H10R2-3,3′)(NHMe2)(NMe 2)Cl2] (R = SiMe3, 9; SiMe2Ph, 10; SiMePh2, 11; SiPh3,12). Structural analyses by X-ray diffraction of (S)-5, (R)-7 and (R,S)-8 show a pseudooctahedral geometry about tantalum with the coordinated dimethylamine ligand located cis to the two naphthoxide oxygen atoms. In the case of (S)-9, (R)-10 and (S)12, the solid-state structure consists of both chloride ligands being located trans to the two naphthoxide oxygen atoms. Solution NMR spectroscopic properties of 5-12 are consistent with an identical structure being adopted in solution with the amine ligands being strongly bound in all cases. When (S)-5 is heated under vacuum the dimethylamine ligand is lost leading to [Ta(O2C 20H10{SiMe3}2-3,3′)(NMe 2)3] (S)-13. Reaction of (S)-5 with SiCl4 leads to a mixture of [Ta(O2C20H10{SiMe 3}2-3,3′)(NHMc2)Cl3] (S)-14 and [Ta(O2C20H10-{SiMe3} 2-3,3′)Cl4][Me2NH2] (S)-15. The solid-state structure of (S)-15 was determined. The amine/ amide ligands in (S)-12 undergo insertion of CS2 leading to the dimethyldithiocarbamate, (S)-[Ta(O2C20H 10-3,3′{SiPh3}2)(CS2NMe 2)2Cl] (S)-16. The solid state structure of (S)-16 consists of a pentagonal bipyramidal geometry about Ta with an axial oxygen and chloride ligand. The Royal Society of Chemistry 2003.
