Investigation of hybrid molecular material prepared by ionic liquid and polyoxometalate anion

Abstract

A solid hybrid molecular material containing 1-butyl 3-methyl imidazolium cations and Keggin anions of phosphotungstic acid has been synthesized. It is fully characterized by CHN analysis, FTIR, XRD, UV-Vis-NIR DRS, 31 P MAS NMR, TGA and SEM. The FTIR spectrum of the compound shows the fingerprint vibrational bands of both Keggin molecular anions and imidazolium cations. The aromatic C-H stretch region (2700-3250 cm -1 ) of imidazolium cation is split due to the interaction between the ring C-H and bulky Keggin anion. The red-shift in the UV-Vis spectra and the downfield 31 P MAS NMR chemical shift also confirm the electrostatic interaction between the ions in the compound. Near IR spectral region (1000-2500 nm) shows the elimination of water in the compound which is hydrophobic.

Temperature‐Dependent Immobilization of a Tungsten Peroxo Complex That Catalyzes the Hydroxymethoxylation of Olefins

“…However, for the recovered SiO 2 -IM-HWPy catalyst this characteristic absorption band became sharper and was shifted to 271 nm. [34] This result suggests that a strong interaction exists between HWPy and SiO 2 -IM, which is in accordance with the FTIR characterization.…”

Phosphotungstic acid supported on magnetic nanoparticles as an efficient reusable catalyst for epoxidation of alkenes

“…1D) shows weak peaks in the range between 1400 and 1630 cm À1 assigned to the imidazole ring [42]. Two other bands at 890 cm À1 and 981 cm À1 are also observed in this spectrum, which are respectively attributed to W-O-W and W5 5O stretching modes of PTA [39,42].…”

Amelioration of H4[W12SiO40] by nanomagnetic heterogenization: For the synthesis of 1H–pyrazolo[1,2‐b]phthalazinedione derivatives

“…Appearance of new peaks at 476, 801 and 1097 cm −1 due to stretching and deformation vibrations of SiO 2 testify to the successful coating of SiO 2 on the magnetite nanoparticles. The retention of Keggin unit after coating is confirmed by the presence of characteristic peaks of H 4 [SiW 12 O 40 ] at 800, 897, 952, 1116 cm −1 which are due to W─O─W, W═O and Si─O vibrations . A broad band at around 3300–3450 cm −1 is due to absorption of OH bonds on the surface of all materials synthesized …”