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In the Laboratory
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The Determination of the Geometry of Cu(II) Complexes: An EPR Spectroscopy Experiment
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Eugenio Garribba and Giovanni Micera
Department of Chemistry, University of Sassari, I-07100 Sassari, Italy
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August 2006
Vol. 83 No. 8
p. 1229
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| Abstract |
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An instrumental experiment is presented in which eleven Cu(II) complexes are studied with electron paramagnetic resonance (EPR) spectroscopy. The EPR spectroscopy allows the characterization of the geometry and electronic structure of the copper complexes. Three common ligands, ethylenediamine (en), 1,10-phenanthroline (phen), and 2,2′-bipyridine (bpy), were used. Examination of the EPR spectra of the solid-state compounds demonstrates that [Cu(en)2(ClO4)2], [Cu(en)2(BF4)2], and [Cu(en)2(NO3)2] have a dx2-y2 ground state and an elongated octahedral geometry; that [Cu(phen)2(H2O)](NO3)2, [Cu(phen)2(H2O)](BF4)2, and [Cu(bpy)2Cl]ClO4 are characterized by a geometry intermediate between the square pyramid and the trigonal bipyramid and a ground state corresponding to the linear combination of the dx2-y2 and dz2 orbitals; and that [Cu(phen)2Cl]ClO4, [Cu(phen)2Br]ClO4, [Cu(bpy)2Br]ClO4, [Cu(phen)2]ClO4, and [Cu(bpy)2I]ClO show a geometry close to the trigonal bipyramid and a ground state of dz2. A theoretical explanation of the results is presented.
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| Supplement |
A detailed description of the experiment, including the background of EPR spectroscopy and the details of the experiment, is available.
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 Contents |
JCE2006p1229W.doc (Microsoft Word)
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| Download |
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| More Information |
Citation |
Garribba, Eugenio; Micera, Giovanni. J. Chem. Educ. 2006 83 1229.
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Keywords |
Coordination Compounds; Copper; Crystal Field / Ligand Field Theory; EPR / ESR Spectroscopy; Hands-On Learning / Manipulatives; Inorganic Chemistry; Instrumental Methods; Laboratory Instruction; Molecular Properties / Structure; Solid State Chemistry; Transition Elements; Upper-Division Undergraduate
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History |
Created:
Last Updated: |
6/21/2006
6/30/2006
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| Home > JCE Print > Journal of Chemical Education > Issues >
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1229
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