Premium
Lanthanide(III) Sandwich and Half‐Sandwich Complexes with Bulky Cyclooctatetraenyl Ligands: Synthesis, Structures, and Magnetic Properties
Author(s) -
Lorenz Volker,
Liebing Phil,
Böhme Michael,
Buchholz Axel,
Plass Winfried,
Geue Niklas,
Hilfert Liane,
Busse Sabine,
Engelhardt Felix,
Hrib Cristian G.,
Edelmann Frank T.
Publication year - 2017
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.201700878
Subject(s) - chemistry , terbium , lanthanide , dimethoxyethane , homoleptic , ligand (biochemistry) , lutetium , crystallography , sandwich compound , crystal structure , trifluoromethanesulfonate , metal , ion , catalysis , x ray crystallography , organic chemistry , biochemistry , receptor , physics , electrode , yttrium , optics , diffraction , electrolyte , oxide
Five new lanthanide(III) sandwich and half‐sandwich complexes with bulky cyclooctatetraenyl ligands have been prepared and fully characterized, including single‐crystal X‐ray structure determination. The treatment of anhydrous lanthanide(III) chlorides, LnCl 3 (Ln = Pr, Tb, Yb), with 2 equivalents of Li 2 COT′′ [COT′′ = 1,4‐bis(trimethylsilyl)cyclooctatetraene dianion] followed by crystallization in the presence of a coordinating solvent afforded the anionic sandwich complexes [Li(THF) 4 ][Pr(COT′′) 2 ] ( 1 ), [Li(DME) 3 ][Tb(COT′′) 2 ] ( 2 ; DME = 1,2‐dimethoxyethane), and [Li(TMEDA) 2 ][Yb(COT′′) 2 ] ( 3 ; TMEDA = N , N , N′ , N′ ‐tetramethylethylenediamine). Attempted oxidation of 2 with silver iodide did not afford the neutral terbium(IV) sandwich complex [Tb(COT′′) 2 ]. Instead, the tri(µ‐iodido)‐bridged dinuclear half‐sandwich complex [Li(DME) 2 ][Tb 2 (µ‐I) 3 (COT′′) 2 ] ( 4 ) was isolated in 72 % yield. In this complex, the Li(DME) 2 fragment is attached to one of the µ‐iodido ligands. A closely related binuclear lutetium complex, [Li(DME) 3 ][Lu 2 (µ‐Cl) 3 (COT big ) 2 ] · DME ( 5 ), was obtained by using the “superbulky“ COT big ligand [COT big = 1,4‐bis(triphenylsilyl)cyclooctatetraenyl dianion]. In addition to the spectroscopic and structural characterization, the magnetic properties of the paramagnetic terbium(III) derivative 2 have been investigated and further complemented by ab initio computational methods. These results have been used to discuss the structural requirements for potential terbium(III) single‐ion magnets.