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Lanthanoid Tetramethylaluminates and Their Paramagnetic NMR Parameters
Author(s) -
Nieland Anja,
Mix Andreas,
Neumann Beate,
Stammler HansGeorg,
Mitzel Norbert W.
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201301266
Subject(s) - chemistry , lanthanide , samarium , paramagnetism , cerium , tetrahydrofuran , amide , hexamethylphosphoramide , holmium , nmr spectra database , nuclear magnetic resonance spectroscopy , crystallography , inorganic chemistry , solvent , stereochemistry , organic chemistry , spectral line , quantum mechanics , ion , laser , physics , astronomy , optics
Tris(tetramethylaluminate)s of the lanthanoids cerium ( 1 ), holmium ( 2 ), and erbium ( 3 ) were synthesized by treating lanthanoid amide complexes of the type [Ln(NMe 2 ) 3 (LiCl) 3 ] with an excess amount of AlMe 3 . These compounds were characterized by single‐crystal X‐ray diffraction, elemental analysis, and NMR spectroscopy. Paramagnetic NMR spectroscopic studies were undertaken to investigate the influence of the compounds on the solvent chemical shifts. NMR parameters for the 1 H, 13 C, and 27 Al nuclei of all the reported lanthanoid tris(tetramethylaluminate)s were measured. The reactions of tris(tetramethylaluminate)s of samarium and holmium with an excess amount of tetrahydrofuran led to [LnMe 2 (thf) 5 ][AlMe 4 ] {Ln = Ho ( 4 ), Sm ( 5 )}. NMR spectroscopic investigations of the paramagnetic holmium and samarium methyl compounds (i.e., 4 , 5 ) as well as the known diamagnetic analogue [YMe 2 (thf) 5 ][AlMe 4 ] revealed methyl group exchange processes in solution.