Synthesis and Proton Conductivity of Two Molybdate Polymers Based on [Mo₈O₂₆]⁴⁻ Anions

Abstract

Two kinds of octamolybdate-based Ni II -coordination polymers were synthesized by hydrothermal methods:The Single crystal X-ray diffraction indicates that compounds 1 and 2 are the 2D layer based on γ-[Mo 8 O 26 ] 4À type and a 1D chain based on β-[Mo 8 O 26 ] 4À type polyoxomolybdate anions, respectively. At 85 °C and 98 % RH, the optimal conductivities of the two compounds are 1.03 × 10 À 2 S cm À 1 and 1.12 × 10 À 2 S cm À 1 , respectively. They exhibit good proton conductivity due to the rich imidazole units as carriers and continuous hydrogen bond networks as proton transport pathway. In this work, two molybdate-based proton conducting materials are designed. [a] W.-B.

Proton Affinity in the Chemistry of Beta-Octamolybdate: HPLC-ICP-AES, NMR and Structural Studies

“…However, several studies of polyoxomolybdates’ reactivity [ 39 ] and catalytic performance (electron transfer reactions) appeared [ 40 , 41 , 42 , 43 , 44 , 45 ]. One of the central complexes in this chemistry is (Bu 4 N) 4 [β-Mo 8 O 26 ] ( Scheme 1 ), which is a standard precursor of all reactions in organic media, leading to a huge number of materials with different properties [ 46 , 47 , 48 , 49 ]. Our ongoing research focuses on the use of the coordination chemistry of the [β-Mo 8 O 26 ] 4− anion in the study of silver chemistry in non-aqueous solutions [ 50 , 51 , 52 ].…”

Polyoxometalate-based metal–organic supramolecular architectures derived from two new pyrimidine-amide ligands as supercapacitors and multifunctional electrochemical sensors

“…S2b, ESI†) correspond to the ν (Mo–O–Mo) and ν (MoO) vibrational absorption in PMo 12 /Mo 8 anion skeleton. 33,34…”

“…6 were obtained over a potential range of −300–500 mV with the scan rates increasing from 20 mV s −1 to 500 mV s −1 . The figures exhibit three clear pairs of redox peaks (I–I′, I–II′ and III–III′) resulting from the redox reaction of Mo atoms in the PMo 12 /Mo 8 polyoxoanions, 33,34 with mean peak potentials of 100, −75, and −214 mV for 1 -CPE and 213, 18, and −198 mV for 2 -CPE, respectively, as calculated from E 1/2 = ( E pa + E pc )/2 (scan rate: 60 mV s −1 ). The inset shows that the peak current increases proportionally with the scanning speed, suggesting that the redox processes of two electrodes are mainly controlled by the surface.…”

“…S2b, ESI †) correspond to the n(Mo-O-Mo) and n(MoQO) vibrational absorption in PMo 12 /Mo 8 anion skeleton. 33,34 The high matching degree between the simulated peaks and the experimental peaks in the PXRD diagram of Fig. S3 (ESI †) indicates that the prepared complexes have good phase purity.…”

Rational design and progress of molybdenum-oxo clusters

“…In 2022, our group reported two g-[Mo 8 O 26 ] 4À and b-[Mo 8 O 26 ] 4À based complexes. 111 For the g-[Mo 8 O 26 ] 4À based complex, when the range of RH from 65% to 98%, the proton conductivity can reach 1.71 Â 10 À7 S cm À1 . For the b-[Mo 8 O 26 ] 4À based complex, the conductivity can reach 4.15 Â 10 À6 S cm À1 at 30 1C and 95% RH, and the water molecules promoted proton conduction process.…”