Issue 10, 2018

Combined HPLC-ICP-AES technique as an informative tool for the study of heteropolyniobates

Abstract

The combined HPLC-ICP-AES technique was applied to study formation of tungstoniobates and phosphomolybdoniobates. Reaction of potassium hexaniobate with tungstic acid results in the formation of mixed Nb/W Lindqvist hexametalates. The metal ratio depends on the relative amount of H2WO4 and reaction time. The most favored species are [Nb4W2O19]6− and [Nb3W3O19]5− which equilibrate with hexaniobate. Formation of [Nb2W4O19]4− was also observed; its share gradually increases with increasing amount of tungstic acid and decreasing pH. Reaction of tungstic acid with telluropentaniobate [TeNb5O19]7− results only in substitution of W for Te producing the same mixed Nb/W Lindqvist anions, but with different distribution of the individual species. The reaction of phosphomolybdic acid (H3PMo12O40) with a niobium oxalate complex, [NbO(C2O4)2(H2O)2], leads to the formation of mixed P/Nb/Mo Keggin anions, unambiguously detected for the first time. Only [PMo11NbO40]4− and [PMo10Nb2O40]5− were observed over the whole concentration range. No trisubstituted [PMo9Nb3O40]6− was detected in the substitution reaction, but is accessible from the self-assembly reaction of the niobium oxalate complex, phosphoric acid, and molybdate.

Graphical abstract: Combined HPLC-ICP-AES technique as an informative tool for the study of heteropolyniobates

Supplementary files

Article information

Article type
Paper
Submitted
11 okt 2017
Accepted
19 mar 2018
First published
20 mar 2018

New J. Chem., 2018,42, 7949-7955

Combined HPLC-ICP-AES technique as an informative tool for the study of heteropolyniobates

P. A. Abramov, T. E. Romanova, V. V. Volchek, A. A. Mukhacheva, N. B. Kompankov and M. N. Sokolov, New J. Chem., 2018, 42, 7949 DOI: 10.1039/C7NJ03917D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements