Syntheses, Crystal Structure, Electrocatalytic, and Magnetic Properties of the Monolanthanide-Containing Germanotungstates [Ln(H2O) n GeW11O39]5- (Ln = Dy, Er, n = 4,3)

Masooma Ibrahim; Israël M Mbomekallé; Pedro de Oliveira; Ananya Baksi; Anthony B Carter; Yan Peng; Thomas Bergfeldt; Sharali Malik; Christopher E Anson

doi:10.1021/acsomega.9b02846

Syntheses, Crystal Structure, Electrocatalytic, and Magnetic Properties of the Monolanthanide-Containing Germanotungstates [Ln(H₂O) _n GeW₁₁O₃₉]^5- (Ln = Dy, Er, n = 4,3)

ACS Omega. 2019 Dec 10;4(26):21873-21882. doi: 10.1021/acsomega.9b02846. eCollection 2019 Dec 24.

Authors

Masooma Ibrahim¹, Israël M Mbomekallé², Pedro de Oliveira², Ananya Baksi¹, Anthony B Carter^{3

4}, Yan Peng³, Thomas Bergfeldt⁵, Sharali Malik¹, Christopher E Anson³

Affiliations

¹ Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
² Equipe d'Electrochimie et Photo-électrochimie, Laboratoire de Chimie Physique, Université Paris-Sud, UMR 8000, CNRS-Université Paris Saclay, Orsay F-91405, France.
³ Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, 76128 Karlsruhe, Germany.
⁴ School of Chemistry University of Southampton University Road, SO17 1BJ Southampton, U.K.
⁵ Institutes for Applied Materials (IAM-AWP), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany.

Abstract

Two monolanthanide-containing polyanions based on monolacunary Keggin germanotungstates [Ln(H₂O) _n GeW₁₁O₃₉]^5- (Ln = Dy, Er, n = 4,3) have been synthesized in simple one-pot synthetic procedure and compositionally characterized in solid state by single-crystal X-ray diffraction, powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis. Electronic absorption and emission spectra of the title compounds in solution were also studied. The [Dy^III(H₂O)₄GeW₁₁O₃₉]^5- Keggin POM exhibits a slow relaxation of magnetization. The cyclic voltammetry measurements and mass spectrometry were carried out to check the stability of the compounds in solution. Both polyanions prove efficient in the electrocatalytic reduction of nitrite. To our knowledge, this observation establishes the first example of electrocatalysis of nitrite reduction by all inorganic monolanthanide-containing germanotungstates family.