Mixed-ligand complexes of osmium(III/IV)8-quinolinolates with one ketoximate ligand

✍ Scribed by Pranab R. Basudhar; Sutapa Sinha; Pradyut K. Das; Barindra K. Ghosh

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 391 KB
• Volume: 21
• Category: Article
• ISSN: 0340-4285
• DOI: 10.1007/bf00136546

✦ Synopsis

A group of mixed-tris chelates of type [OsAQ2 ] [A=isonitrosoacetophenonate (A ~) and isonitrosopropiophenonate (A2); Q = deprotonated 8-quinolinol (QI) and 2-methyl-8-quinolinol (Q2)] have been prepared by two distinct synthetic approaches. [OsAQ2] +, obtained by Ce Iv oxidation of [OsAQ2], can be regenerated by hydrazine hydrate reduction of the former. The complexes, characterized by physico-chemical, magnetic and spectroscopic methods, exhibit several spin-allowed and spin-forbidden charge transfer transitions in their electronic spectra. In MeCN solution the OsN30 3 unit displays a nearly-reversible OsW-Os m change and an Osm-Os" couple in the ca. -1.0-+0.3 V range versus s.c.e. The stability of the metal oxidation levels is discussed in terms of the chemical and electrochemical results.