Cobalt(III) complexes of a-w- diaminocarboxylic acids and chloroquine
Loading...
Date
2001
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
a-w-Diaminocarboxylic acids, such as lysine and 2,3-diaminopropionic acid (2,3-DAPH), are trifunctional, and thus, when only two sites are available for coordination, an interesting question is posed as to which functional groups are utilised in chelation. A series of cobalt(III) complexes of the formulation [Co(en)2AA]2+, where en is ethylenediamine and AA represents lysine and DL-2,3-DAP, were prepared. In addition, complexes of the type [Co(AA)(AAH)Cl2] and [Co(AA)2]+, where AA is DL-2,3-DAP, have been synthesised. The compounds were characterised using elemental analysis, NMR, IR and electronic spectroscopy and mass spectrometry. The reaction of czs-[Co(en)2Cl2]Cl with lysine yielded two products notably, [Co(en)2(lys)]2+, within which lysine coordinates via the a-nitrogen and oxygen donor atoms, and [Co(en)3]3+. The reaction of c/s-[Co(en)2Cl2]Cl with DL-2,3-DAPH, however, yielded three products, viz. [Co(en)2(2,3-DAP)]2+, in which the glycinate portion of 2,3-DAP is involved in chelation, [Co(2,3-DAP)2]+ where 2,3-DAP acted as a tridentate ligand, and [Co(en)3]3+. In [Co(2,3-DAP)(2,3-DAPH)Cl2], one of the 2,3-DAP ligands coordinated via the two amino groups leaving the carboxylic acid group free whilst the second ligand coordinated via the glycinate portion leaving the terminal amino group free.
Description
Submitted to the Faculty of Science and Agriculture in partial fulfilment of the requirements for the Degree of Master of Sciences in the department of Chemistry at the University of Zululand, 2001.
Keywords
Chemistry, Cobalt