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Synthesis and characterization of the chromium(III) complexes of ethylene cross-bridged cyclam and cyclen ligands

Maples, Danny L.; Maples, Randall D.; Hoffert, Wesley A.; Parsell, Trenton H.; Asselt, Allan van; Silversides, Jon D.; Archibald, Stephen J.; Hubin, Timothy J.


Danny L. Maples

Randall D. Maples

Wesley A. Hoffert

Trenton H. Parsell

Allan van Asselt

Jon D. Silversides

Timothy J. Hubin


Dichloro(4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2] tetradecane) chromium(III) chloride, Dichloro(4,10-dibenzyl-1,4,7,10-tetraazabicyclo[ 5.5.2] tetradecane) chromium(III) chloride, and Dichloro(4,11-dimethyl- 1,4,8,11-tetraazabicyclo[6.6.2] hexadecane) chromium)(III) chloride have been prepared by the reaction of anhydrous chromium(III) chloride with the appropriate cross-bridged tetra-azamacrocycle. Aquation of these complexes proved difficult, but Chlorohydroxo(4,11-dimethyl- 1,4,8,11tetraazabicyclo[6.6.2] hexadecane) chromium)(III) chloride was synthesized directly from chromium(II) chloride complexation followed by exposure or the reaction to air in the presence of water. The four complexes were characterized by X-ray crystal structure determination. All contain the chromium(III) ion in a distorted octahedral geometry and the macrocycle in the cis-V configuration, as dictated by the ethylene cross-bridge. Further characterization of the hydroxo complex reveals a magnetic moment of mu(eff) = 3.95 B.M. and electronic absorbtions in acetonitrile at lambda(max) = 583 nm (epsilon = 65.8 L/cm mol), 431 nm (epsilon = 34.8 L/cm mol) and 369 nm (epsilon = 17 L/cm mol). (C) 2008 Elsevier B.V. All rights reserved.

Journal Article Type Article
Publication Date Apr 20, 2009
Print ISSN 0020-1693
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 362
Issue 6
Pages 2084-2088
APA6 Citation Maples, D. L., Maples, R. D., Hoffert, W. A., Parsell, T. H., Asselt, A. V., Silversides, J. D., …Hubin, T. J. (2009). Synthesis and characterization of the chromium(III) complexes of ethylene cross-bridged cyclam and cyclen ligands. Inorganica Chimica Acta, 362(6), 2084-2088.
Keywords Chromium(III); Bridged tetraazamacrocycle; Cyclam; Cyclen
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