SOMC grafting of vanadium oxytriisopropoxide (VO(OiPr)3) on dehydroxylated silica; analysis of surface complexes and thermal restructuring mechanism
Type
ArticleAuthors
Hogerl, Manuel PeterSerena Goh, Li Min
Abou-Hamad, Edy
Barman, Samir
Dachwald, Oliver
Pasha, Farhan Ahmad
Pelletier, Jeremie

Köhler, Klaus
D'Elia, Valerio
Cavallo, Luigi

Basset, Jean-Marie

KAUST Department
Chemical Science ProgramImaging and Characterization Core Lab
KAUST Catalysis Center (KCC)
NMR
Physical Science and Engineering (PSE) Division
Date
2018Permanent link to this record
http://hdl.handle.net/10754/628452
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Vanadium oxytriisopropoxide (VO(OPr)), 1, was grafted on highly dehydroxylated silica (SiO: aerosil silica treated at 700 °C under high vacuum) to generate compound 2 following the concepts and methodology of surface organometallic chemistry (SOMC). The resulting compound was analyzed by elemental analysis, FT-IR, H, C and V solid state (SS) NMR, Raman and EPR spectroscopies. The grafting reaction of 1 to generate 2 was found to lead to the formation of a monopodal surface complex [(Si-O-)V(O)(OPr)], 2m, as well as bipodal [(Si-O-)V(O)(OPr)], 2b, formed along with (Si-O-Pr) moieties as an effect of the classical rearrangement of 2m with strained siloxane bridges. Upon controlled thermal treatment at 200 °C under high vacuum, 2m and 2b were found to mainly rearrange to tetrahedral VO moieties [(Si-O-)V(O)] (3) with formation of propylene whereas the (Si-O-Pr) groups were preserved. The mechanism of the thermal rearrangement of the isopropoxide groups was investigated by a DFT approach revealing the occurrence of a concerted γ-H-transfer and olefin elimination mechanism.Citation
Högerl MP, Serena Goh LM, Abou-Hamad E, Barman S, Dachwald O, et al. (2018) SOMC grafting of vanadium oxytriisopropoxide (VO(OiPr)3) on dehydroxylated silica; analysis of surface complexes and thermal restructuring mechanism. RSC Advances 8: 20801–20808. Available: http://dx.doi.org/10.1039/c8ra02419g.Sponsors
This work was funded by King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. The authors declare no competing financial interest. V. D. E. thanks the Thailand Research Fund (Grant No. RSA6080059) for funding this research.Publisher
Royal Society of Chemistry (RSC)Journal
RSC AdvancesAdditional Links
http://pubs.rsc.org/en/content/articlehtml/2018/ra/c8ra02419gae974a485f413a2113503eed53cd6c53
10.1039/c8ra02419g
Scopus Count
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