Nine new vanadium oxyfluorides, containing ten different oligomeric vanadium (oxy)fluoride anions have been prepared by solvothermal synthesis in water-ethylene glycol and using organic cations as co-crystallising agents. Crystal structures are reported for each. Amongst the ten structure types, five represent previously unobserved moieties, including one monomeric unit (cis-[VOF4(H2O)]2-), two dimers ([V2O2F6(H2O)2]2- and [V2O2F8]4-) and two tetramers (both isomers of composition [V4O4F14]6-). Structural relationships between the various units are discussed, together with some rationalisation of their occurrence as a function of synthetic variables.
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http://dx.doi.org/10.1039/b702146a | DOI Listing |
ACS Appl Mater Interfaces
February 2024
Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106335, Taiwan.
Surface electroactive sites for tungstate zirconia (WZ) were created by utilizing tungstate-immobilized UiO-66 as precursors via a double-solvent impregnation method under a mild calcination temperature. The WZ-22-650 catalyst, containing a moderate W content (22%), demonstrated a high density of surface electroactive sites. Proper heat treatment facilitated the binding of oligomeric tungsten clusters to stabilized tetragonal ZrO, resulting in improved catalytic performance toward the VO/VO redox couples compared to other tested samples.
View Article and Find Full Text PDFMaterials (Basel)
January 2022
Department of Animal Nutrition, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna, Poland.
Currently, new precatalysts for olefin oligomerization are being sought in the group of vanadium(IV) complexes. Thus, the aim of our research was to examine the catalytic activity of the oxovanadium(IV) dipicolinate complex [VO(dipic)(HO)] 2 HO (dipic = pyridine-2,6-dicarboxylate anion) in 2-propen-1-ol oligomerization as well as to characterize oligomerization products using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS), infrared spectroscopy (IR) and nuclear magnetic resonance (NMR). The oligomerization process took place at room temperature, under atmospheric pressure and under nitrogen atmosphere to prevent oxidation of the activator MMAO-12-the modified methylaluminoxane (7 wt.
View Article and Find Full Text PDFMaterials (Basel)
December 2021
Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.
So far, few microclusters containing vanadium have been described in the literature. In this report, the synthesis protocol for the preparation of oxovanadium (IV) microclusters with 2-phenylpyridine is shown for the first time. Moreover, the crystal structure of these microclusters is also studied through the use of X-rays.
View Article and Find Full Text PDFChem Commun (Camb)
August 2021
Department of Chemistry, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
Using a V(ii) complex as a reducing reagent, we demonstrate controlled reduction of isocyanides, resulting in decyanation of alkyl isocyanides to form a V(iii) cyanide complex or oligomerization of aryl isocyanides to form trimers and a tetramer. The pathways leading to the trimers involve a divanadium ynediamido intermediate, which further reacts with the third isocyanide molecule to selectively produce a tri(imino)deltate or an indolenine complex, by altering the temperature and stoichiometry.
View Article and Find Full Text PDFJ Colloid Interface Sci
October 2021
State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, China.
Compared with industrial used Pt- and Cr-based catalyst in dehydrogenation (DH) of light alkanes, the sulfide V-K/γ-AlO catalyst reported in this study shows lower cost and toxicity, and significant DH performance. The yield to isobutene reached as high as 52.9%, which is among the highest reported to date.
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