Further 31-P NMR investigation of heteropolytungstate chemistry in nonpolar solvents

CHED 1205

Jane Arcadi, arcadij@canisius.edu, Mark Makar, makarm@canisius.edu, and Mariusz Kozik, kozik@canisius.edu. Department of Chemistry and Biochemistry, Canisius College, 2001 Main Street, Buffalo, NY 14208
Recently we discovered by 31-P NMR spectroscopy that the structures of Transition Metal Substituted Heteropolytungstates (TMSHTs) in nonpolar solvents are more complex than the structures published in the literature. As the nonpolar solvent is dried, several new signals appear in 31-P NMR spectrum. One of these peaks becomes very strong in the presence of excess tetraheptylammonium bromide, THABr. We interpreted these results as indicating that during phase transfer of TMSHTs, mixing potassium salt of TMSHT in water with THABr in toluene, some KBr is also transferred into toluene.

This presentation corrects other previously believed "facts." It was believed in the past that chloride ions, when coordinated to transition metal within TMSHT in toluene, can not be replaced by any other ions. Data presented in this poster show otherwise. We demonstrate that chloride ions coordinated to cobalt(II) in TMSHT can be replaced by either water or bromide.