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Polynuclear Complexes Containing the Redox Noninnocent Schiff Base Ligand 2‐[( E )‐2‐Mercaptophenylimino]methyl‐4,6‐di‐ tert ‐butylphenolate(2–)
Author(s) -
Roy Nabarun,
Sproules Stephen,
Bothe Eberhard,
Weyhermüller Thomas,
Wieghardt Karl
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.200900168
Subject(s) - chemistry , deprotonation , ligand (biochemistry) , schiff base , triethylamine , redox , radical , electron paramagnetic resonance , crystallography , medicinal chemistry , stereochemistry , inorganic chemistry , organic chemistry , ion , biochemistry , physics , receptor , nuclear magnetic resonance
The N,O,S‐donor Schiff base ligand 2‐[( E )‐(2‐mercaptophenylimino)methyl]‐4,6‐di‐ tert ‐butylphenolate(2–) (H 2 L) was deprotonated with triethylamine (2 equiv.) and treated with equimolar amounts of Cu(OAc) 2 · H 2 O, PtCl 2 , Pd(OAc) 2 , and CoCl 2 , respectively. The versatility of L 2– is realized in the self‐assembly of four polynuclear complexes: dimeric [Cu II 2 (L) 2 ] ( 1 ), trimeric [Pt II 3 (L) 3 ] ( 2 ), and the two tetrameric complexes [Pd II 4 (L) 4 ] ( 3 ) and [Co III 4 (L) 6 ] ( 4 ), all characterized by X‐ray crystallography. Electronic structure calculations (DFT) on dimeric 1 show that the two singly occupied Cud x 2 – y 2orbitals are antiferromagnetically coupled, and the calculated J = –724 cm –1 agrees well with the experimental data. Complexes 3 and 4 possess several reversible one‐electron, ligand‐centered oxidations with electronic absorption and EPR spectroscopy displaying all the hallmarks of coordinated phenoxyl radicals. This feature further endorses our assignment of the generation of phenoxyl radicals upon oxidation and underscores the redox noninnocence of this Schiff base ligand.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)