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New Single‐Molecule Magnets by Site‐Specific Substitution: Incorporation of “Alligator Clips” into Fe 4 Complexes
Author(s) -
Barra AnneLaure,
Bianchi Federica,
Caneschi Andrea,
Cornia Andrea,
Gatteschi Dante,
Gorini Lapo,
Gregoli Luisa,
Maffini Monica,
Parenti Francesca,
Sessoli Roberta,
Sorace Lorenzo,
Talarico Anna Maria
Publication year - 2007
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.200700382
Subject(s) - chemistry , hydroxymethyl , crystallography , magnetization , molecule , magnetic anisotropy , bimetallic strip , electron paramagnetic resonance , stereochemistry , nuclear magnetic resonance , catalysis , organic chemistry , physics , quantum mechanics , magnetic field
“Alligator clips” suitable for grafting on H‐terminated silicon or gold surfaces have been incorporated into single‐molecule magnets (SMMs) of the Fe 4 family. Tripodal ligands 2,2‐bis(hydroxymethyl)‐10‐undecen‐1‐ol (H 3 L 1 ) and 11‐(acetylthio)‐2,2‐bis(hydroxymethyl)undecan‐1‐ol (H 3 L 2 ) have been used to replace the six methoxide bridges in [Fe 4 (OMe) 6 (dpm) 6 ], affording new Fe 4 derivatives [Fe 4 (L 1 ) 2 (dpm) 6 ] ( 1 ) and [Fe 4 (L 2 ) 2 (dpm) 6 ] ( 2 ) in high yield (Hdpm = dipivaloylmethane). The molecular structures have been unambiguously established by XRD combined with ESI‐MS and magnetic characterization techniques, including DC and AC magnetometry and high‐frequency EPR spectroscopy. The two SMMs have an S = 5 ground state and an easy‐axis magnetic anisotropy leading to slow relaxation of the magnetization at low temperature, with effective anisotropy barriers of 15.9(2) K in 1 and 15.1(2) K in 2 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)