Organoarsonate Functionalization of Heteropolyoxotungstates

Xiaofeng Yi; Natalya V Izarova; Paul Kögerler

doi:10.1021/acs.inorgchem.7b01928

Organoarsonate Functionalization of Heteropolyoxotungstates

Inorg Chem. 2017 Nov 20;56(22):13822-13828. doi: 10.1021/acs.inorgchem.7b01928. Epub 2017 Nov 9.

Authors

Xiaofeng Yi^{1

2}, Natalya V Izarova¹, Paul Kögerler^{1

2}

Affiliations

¹ Jülich-Aachen Research Alliance (JARA-FIT) and Peter Grünberg Institute, PGI 6, Forschungszentrum Jülich , D-52425 Jülich, Germany.
² Institute of Inorganic Chemistry, RWTH Aachen University , D-52074 Aachen, Germany.

Abstract

Functionalization of the {P₈W₄₈} polyoxotungstate (POT) archetype with aromatic organoarsonates results in the first homometallic {P₈W₄₈} derivatives, with the general formula [(RAs^VO)₄P^V₈W^VI₄₈O₁₈₄]^32- [R = C₆H₅ (1) or p-(H₂N)C₆H₄ (2)]. Short As-O bonds here induce unusual bending of the otherwise rigid {P₈W₄₈} macrocycle, breaking its D_4h symmetry. The obtained species also represent the first lacunary POTs functionalized with organoarsonates and can potentially act as polyoxometalate precursors themselves. We elaborate solution stability in different aqueous media using ¹H and ³¹P NMR spectroscopy and possible pathways for subsequent transformations in aqueous solutions of the functionalized polyanions. Recrystallization of the K⁺/Li⁺/dimethylammonium salt of 2 from 4 M LiCl solution yielded a further functionalized POT, [(H₃NC₆H₄AsO)₃P₈W₄₈O₁₈₄H_x{WO₂(H₂O)₂}_0.4]^(30.2-x)- (3), revealing dissociation of the organoarsonate fragments in slightly acidic aqueous solutions followed by their rearrangement within the inner POT cavity.