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Bimolecular Extrusion of TeR 2 from β‐Diketiminato Supported Scandium Bis‐tellurolates
Author(s) -
Knight Lisa K.,
Piers Warren E.,
McDonald Robert
Publication year - 2000
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20001201)6:23<4322::aid-chem4322>3.0.co;2-0
Subject(s) - scandium , chemistry , dimer , telluride , crystallography , extrusion , stereochemistry , materials science , inorganic chemistry , organic chemistry , metallurgy
Reaction of the well‐defined, base‐free dialkyl scandium compounds L n Sc(CH 2 SiMe 3 ) 2 supported by the β‐diketiminato ligands ArNC(R)CHC(R)NAr (Ar=2,6‐diisopropyl; R=Me, L 1 ; R= t Bu, L 2 ) with two equivalents of n Bu 3 P=Te gives the bis‐tellurolate complexes L n Sc(TeCH 2 SiMe 3 ) 2 , 1 b (L 1 ) and 2 b (L 2 ). Tellurolate 2 b was isolated and fully characterized, including an X‐ray structure analysis, and exhibits two chemically distinct tellurolate ligands in solution on the NMR time scale. Tellurolate 1 b is only moderately stable and decomposes with elimination of two equivalents of Te(CH 2 SiMe 3 ) 2 to form the dimeric bis‐telluride 1 d . This compound was characterized by X‐ray crystallography and elemental analysis. In contast, tellurolate 2 b decomposes with loss of only one equivalent of Te(CH 2 SiMe 3 ) 2 , leading to the formation of a dinuclear complex with one bridging telluride unit joining two L 2 Sc(TeCH 2 SiMe 3 ) fragments. This compound was also structurally characterized. The solution behavior of this material is complex, as it exists as three conformational isomers that undergo slow exchange on the NMR time scale. The production of dimer 2 c , along with the results of crossover experiments, suggest strongly that TeR 2 elimination from these bis‐tellurolates is bimolecular.