Substituted thiourea ligands bind in a bidentate manner forming a four-membered ring through the sulfur atom and a deprotonated thiourea nitrogen atom when reacted with [(en)2Co(OSO2CF3)2]+ in tetramethylene sulfone. Reaction of unsymmetrical ligands results in the formation of coordination isomers, some of which can be separated by column chromatography using Sephadex SPC-25. Coordination isomers are easily distinguishable based on visible and 1H NMR spectroscopy . Twelve para-substituted and one meta-substituted ligands were studied: N,N′-dibenzylthiourea (1a); N-(R)phenyl-N′-benzylthiourea R≤H (2a), NO2 (2b), CH3 (2c); N-(R)phenyl-N′-(R′)phenylthiourea R, R′: H, H (3a), H, CH3 (3b), OCH3, NO2 (3c), CH3, NO2 (3d); N-methyl-N′-(R)phenylthiourea R≤H (4a), CH3 (4b), OCH3 (4c), NO2 (4d), 3-CH3 (4e). The solid state structure (X-ray) of one isomer of Co-4a as its perchlorate salt confirms the coordination mode suggested by 1H NMR spectroscopy and shows that the Co-N bond trans to the coordinated thiourea sulfur induces a structural trans effect of 0.019Å.
|Number of pages||8|
|Journal||Australian Journal of Chemistry|
|State||Published - 2013|
Bibliographical noteFunding Information:
Funding for the Thermo Finnigan LCQ Deca Max was through NSF Grant 0421581 to Matthew Saderholm at Berea College. The authors thank Dr Saderholm for his assistance obtaining the mass spectrometry data. Initial funding for this work was provided by the Appalachian College Association, Berea, KY.
ASJC Scopus subject areas
- Chemistry (all)