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Lanthanide Complexes Coordinated by a Dianionic Bis(amidinate) Ligand with a Rigid Naphthalene Linker
Author(s) -
Yakovenko Marina V.,
Cherkasov Anton V.,
Fukin Georgy K.,
Cui Dongmei,
Trifonov Alexander A.
Publication year - 2010
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.201000330
Subject(s) - chemistry , deprotonation , ligand (biochemistry) , lanthanide , amidine , medicinal chemistry , stereochemistry , linker , alkylation , naphthalene , crystallography , ion , catalysis , organic chemistry , biochemistry , receptor , computer science , operating system
Abstract The synthetic pathway to a new bis(amidine) ligand with a conformationally rigid naphthalene linker, 1,8‐C 10 H 6 [NHC( t Bu)=N(2,6‐Me 2 –C 6 H 3 )][N=C( t Bu)NH(2,6‐Me 2 –C 6 H 3 )] ( 3 ) was elaborated. Deprotonation of this bis(amidine) ligand with two equivalents of n BuLi and subsequent reaction with anhydrous LnCl 3 (Ln = Y, Nd, Sm) allowed the synthesisof the chlorido complexes [1,8‐C 10 H 6 {NC( t Bu)N‐2,6‐Me 2 –C 6 H 3 } 2 ]YCl(dme) ( 4 ), [1,8‐C 10 H 6 {NC( t Bu)N‐2,6‐Me 2 –C 6 H 3 } 2 ]Nd(dme)(μ‐Cl) 2 Li(dme) ( 5 ), and [1,8‐C 10 H 6 {NC( t Bu)N‐2,6‐Me 2 –C 6 H 3 } 2 ]Sm(thf)(μ‐Cl) 2 Li(thf) 2 ( 6 ), which are coordinated by the linked dianionic bis(amidinate) ligand. The structures of complexes 4 – 6 were established by X‐ray diffraction studies, which reveal that the new ligand framework can coordinate to the lanthanide atoms in different fashions depending on the central atom ion size. Alkylation of complex 6 with equimolar amounts of LiCH 2 SiMe 3 afforded the unexpected amido–amidinate complex [{1,8‐C 10 H 6 (NC( t Bu)N‐2,6‐Me 2 –C 6 H 3 ) 2 }{1,8‐C 10 H 6 (NC( t Bu)N‐2,6‐Me 2 –C 6 H 3 )(NH)}Sm][Li(dme) 3 ] ( 7 ), which obviously results from the cleavage of one amidinate group during decomposition of the transient alkyl species and ligand redistribution.