Premium
First Row Transition Metal Aminopyridinates – the Missing Complexes
Author(s) -
Glatz Germund,
Demeshko Serhiy,
Motz Günter,
Kempe Rhett
Publication year - 2009
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.200801094
Subject(s) - chemistry , homoleptic , transition metal , trimethylsilyl , ligand (biochemistry) , metathesis , pyridine , manganese , metal , crystal structure , scandium , stereochemistry , crystallography , medicinal chemistry , inorganic chemistry , catalysis , polymerization , organic chemistry , biochemistry , polymer , receptor
Lithiated 4‐methyl‐2‐[(trimethylsilyl)amino]pyridine (Ap TMS H) undergoes a salt metathesis reaction with [ScCl 3 (thf) 3 ] and FeCl 3 , at low temperature in thf, to yield the homoleptic complexes [Sc(Ap TMS ) 3 ] ( 1 ) and [Fe(Ap TMS ) 3 ] ( 2 ). An analogous reaction with MnCl 2 , CoCl 2 and FeCl 2 using two equivalents of 4‐ tert ‐butylpyridine ( t BuPy) as additional donor ligand affords the structurally analogous cis complexes [Mn(Ap TMS ) 2 ( t BuPy) 2 ] ( 3 ), [Co(Ap TMS ) 2 ( t BuPy) 2 ] ( 4 ) and [Fe(Ap TMS ) 2 ( t BuPy) 2 ] ( 5 ). If FeCl 2 is used without t BuPy, the highly symmetric trinuclear complex [Fe 3 (Ap TMS ) 6 Li 2 O] ( 6 ) is obtained. Furthermore, the use of ZnCl 2 in a reaction with lithiated Ap TMS H yields the dimeric complex [Zn 2 (Ap TMS ) 4 ] ( 7 ) in which two Ap TMS ligands bridge the two metals. All complexes have been characterised by X‐ray crystal structure analysis. To the best of our knowledge, complexes 1 and 2 and 5 are the first scandium and iron aminopyridinates, respectively, and complex 3 is the first manganese aminopyridinate complex which contains no additional anionic ligand. Complexes 4 and 7 are rare examples of cobalt and zinc aminopyridinates. This study proves that aminopyridinato ligands are highly universal ligands since they are able to stabilize early and late transition metals. Aminopyridinates of every first row transition metal are now available. The magnetic properties of all paramagnetic complexes were investigated. All complexes are high‐spin complexes and the trinuclear iron complex 6 exhibits a weak antiferromagnetic coupling.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)