Aqueous tantalum polyoxometalate reactivity with peroxide. Issue 26 (20th June 2017)

• Record Type: Journal Article
• Authors: Fullmer, Lauren B.; Malmberg, Christopher E.; Fast, Dylan B.; Wills, Lindsay A.; Cheong, Paul Ha-Yeon; Dolgos, Michelle R.; Nyman, May
• Is Part Of: Dalton transactions. Volume 46:Issue 26(2017)
• Page Start: 8486
• Page End: 8493
• Publication Date: 2017-06-20
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c7dt01478c
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Peroxide ligation promotes linking of Ta-polyoxometalates, the solution speciation elucidated by small and wide angle and total X-ray scattering. Abstract : Peroxide ligation of aqueous metal–oxo clusters provides rich speciation and structural diversity, radiation sensitivity for manipulation with light, and both broadens and shifts pH-range stability. Here we demonstrate peroxide ligation of the polyoxometalate (POM) [Ta6 O19 ] 8− . We study in detail solution speciation of the peroxide-substituted cluster, and benchmark it to the peroxide-ligated niobate analogue, [Nb6 O10 (OH)3 (O2 )6 ] 5−, whose solid-state structure has been reported. Raman and electrospray ionization mass spectroscopy do not detect any significant differences between the two analogues. However, small and wide-angle and total X-ray scattering strongly indicate that peroxide promotes linking of the hexameric tantalate clusters, rather than terminating and capping the clusters, as observed for the niobate analogue. We used computational studies to identify Raman peak positions, determine the energetics of exchange of oxo-ligands for peroxo-ligands, and provide models to help explain the X-ray scattering data. Understanding the solution speciation of peroxide-substituted polyoxotantalates is an important step towards its use in solution processed thin film materials, as well as developing new Ta-POM chemistry.