A HPLC-ICP-AES technique for the screening of [XW11NbO40](n-) aqueous solutions

作者：Shmakova Alexandra A; Akhmetova Maria M; Volchek Victoria V; Romanova Tamara E; Korolkov Ilya; Sheven Dmitri G; Adonin Sergey A^*; Abramov Pavel A^*; Sokolov Maxim N

来源：New Journal of Chemistry, 2018, 42(10): 7940-7948.

DOI：10.1039/c7nj04702a

The reaction of H-3[PW12O40] with (NH4)[NbO(C2O4)(2)(H2O)(2)]center dot 3H(2)O leads to the straightforward incorporation of Nb into a Keggin anion backbone resulting in [PW11NbO40](4-) in nearly quantitative yield. Solution behavior of this monosubstituted anion as a function of pH was studied through P-31 NMR and HPLC-ICP-AES techniques (a combination of chromatography and ICP-AES). Increasing of the pH leads to the elimination of Nb from the structure with the formation of mixed Nb/W Lindqvist-type anions and monolacunary [PW11O39](7-). In aged solutions of [PW11NbO40](4-) the formation of a mixture of [PNb2W10O39](5-) isomers was detected. The HPLC-ICP-AES technique was applied for the study of [BW11O39](9-) behavior in aqueous solutions at different pH values and for monitoring the [GeW11O39](4-) reaction with the niobium oxalate complex. Despite the presence of the nucleophilic Nb=O group [PW11NbO40](4-) does not coordinate Co2+ in DMF or Ni2+ in CH3CN, producing double [Co(DMF)(6)][PW11NbO40]center dot 2.6DMF (2) and [Ni(CH3CN)(5.5)(H2O)(0.5)](2)[PW11NbO40]center dot 1.7CH(3)CN (3) salts instead.

• 出版日期2018-5-21