Synthesis and X-ray crystal structure determination of the first copper(II) complexes of tetraazamacrocycle-glyoxal condensates
UNSPECIFIED. (2002) Synthesis and X-ray crystal structure determination of the first copper(II) complexes of tetraazamacrocycle-glyoxal condensates. INORGANIC CHEMISTRY, 41 (26). pp. 7006-7014. ISSN 0020-1669Full text not available from this repository.
Official URL: http://dx.doi.org/10.1021/ic020386+
Novel Cu-II complexes CuLCl2 (L = 1-4) have been synthesized containing the metal bound to a well-known type of tetracyclic bisaminal formed from the condensation of glyoxal and tetraazamacrocycles (1 = cyclam-glyoxal condensate, 2 = aneN4-glyoxal condensate, 3 = cyclen-glyoxal condensate, 4 = isocyclam-glyoxal condensate). The four-coordinate complexes were characterized by X-ray crystallography, electronic spectroscopy, solid-state magnetic moments, and electron spin resonance spectroscopy. The tetracyclic bisaminals, although having four potential donor atoms, are bound in a cis-bidentate fashion to Cu-II with two additional cis-chloride donors. The ligands take up folded conformations, and with the exception of ligand 4, only nonadjacent nitrogen atoms coordinate. As expected, ligand 2 in Cu(2)Cl-2 has a folded structure similar to those of the previously characterized 1 and 3. The conformation of 4 in the complex Cu(4)Cl-2 differs from 1-3 in that three nitrogens direct their lone pairs to one side of the folded tetracycle, with adjacent nitrogen atoms coordinated to Cu-II. This difference is probably caused by the presence of the more flexible seven-membered ring rather than the five- to six-membered rings in 1-3. Air oxidation of Cu-I in the presence of 1 or 3 results in bis(mu-hydroxo) dimers as characterized by X-ray crystal structures, suggesting dioxygen binding, followed by O-O bond splitting to give the Cu2O2 diamond core.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Journal or Publication Title:||INORGANIC CHEMISTRY|
|Publisher:||AMER CHEMICAL SOC|
|Date:||30 December 2002|
|Number of Pages:||9|
|Page Range:||pp. 7006-7014|
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