Interactions of cobalt tetrasulfophthalocyanine with thiolate anions in dimethylformamide

✍ Scribed by Eduard M. Tyapochkin; Evguenii I. Kozliak

• Book ID: 102398851
• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 167 KB
• Volume: 05
• Category: Article
• ISSN: 1088-4246
• DOI: 10.1002/jpp.341

✦ Synopsis

Thiolate complexes of cobalt tetrasulfophthalocyanine ( CoTSPc ), possible intermediates of the industrial removal of mercaptans from oil fractions (Merox process), were studied in dimethylformamide, dimethylsulfoxide, and other polar aprotic solvents by UV-vis, ^1^ H NMR, and ESR spectroscopy. All thiolates react with Co ^II^ TSPc under anaerobic conditions with 1:1 stoichiometry. All tested aliphatic thiolates, regardless of their basicity, reduce Co ^II^ TSPc to form Co ^I^ TSPc derivatives. Low-basicity thiolates also form unstable non-reduced ( RS ^-^) Co ^II^ TSPc complexes as dead-end products. Indirect kinetic evidence was obtained for electron transfer from the axial ligand to metal via the phthalocyanine equatorial ligand. ^1^ H NMR and binding studies revealed sulfur–cobalt interactions in the Co ^I^ TSPc product, thus indicating an axial ligand attachment to Co ^I^ TSPc . Low-basicity aromatic thiolates (pentachloro- and pentafluorobenzenethiolate) form ( RS ^-^) Co ^II^ TSPc complexes, which are stable toward intramolecular metal reduction. This effect is indicative of possible π-stacking between the aromatic thiolate and phthalocyanine ring.