SOMC grafting of vanadium oxytriisopropoxide (VO(O: IPr)3) on dehydroxylated silica; Analysis of surface complexes and thermal restructuring mechanism

Manuel P. Högerl; Li Min Serena Goh; Edy Abou-Hamad; Samir Barman; Oliver Dachwald; Farhan Ahmad Pasha; Jeremie Pelletier; Klaus Köhler; Valerio D'Elia; Luigi Cavallo; Jean Marie Basset

doi:10.1039/c8ra02419g

SOMC grafting of vanadium oxytriisopropoxide (VO(O^{: I}Pr)₃) on dehydroxylated silica; Analysis of surface complexes and thermal restructuring mechanism

Manuel P. Högerl, Li Min Serena Goh, Edy Abou-Hamad, Samir Barman, Oliver Dachwald, Farhan Ahmad Pasha, Jeremie Pelletier, Klaus Köhler, Valerio D'Elia^*, Luigi Cavallo, Jean Marie Basset

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

14 Scopus citations

Abstract

Vanadium oxytriisopropoxide (VO(OⁱPr)₃), 1, was grafted on highly dehydroxylated silica (SiO_2-700: 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, ¹H, ¹³C and ⁵¹V 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)(OⁱPr)₂], 2m, as well as bipodal [(Si-O-)₂V(O)(OⁱPr)], 2b, formed along with (Si-O-ⁱPr) 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 VO₄ moieties [(Si-O-)₃V(O)] (3) with formation of propylene whereas the (Si-O-ⁱPr) 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.

Original language	English
Pages (from-to)	20801-20808
Number of pages	8
Journal	RSC Advances
Volume	8
Issue number	37
DOIs	https://doi.org/10.1039/c8ra02419g
State	Published - 2018
Externally published	Yes

Bibliographical note

Funding Information:
This work was funded by King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. The authors declare no competing nancial interest. V. D. E. thanks the Thailand Research Fund (Grant No. RSA6080059) for funding this research.

Publisher Copyright:
© 2018 The Royal Society of Chemistry.

ASJC Scopus subject areas

General Chemistry
General Chemical Engineering

Access to Document

10.1039/c8ra02419g

Cite this

Högerl, M. P., Serena Goh, L. M., Abou-Hamad, E., Barman, S., Dachwald, O., Pasha, F. A., Pelletier, J., Köhler, K., D'Elia, V., Cavallo, L., & Basset, J. M. (2018). SOMC grafting of vanadium oxytriisopropoxide (VO(O^{: I}Pr)₃) on dehydroxylated silica; Analysis of surface complexes and thermal restructuring mechanism. RSC Advances, 8(37), 20801-20808. https://doi.org/10.1039/c8ra02419g

@article{c27b41cbb61b405ea31ac62015d474a2,

title = "SOMC grafting of vanadium oxytriisopropoxide (VO(O: IPr)3) on dehydroxylated silica; Analysis of surface complexes and thermal restructuring mechanism",

abstract = "Vanadium oxytriisopropoxide (VO(OiPr)3), 1, was grafted on highly dehydroxylated silica (SiO2-700: 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, 1H, 13C and 51V 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)(OiPr)2], 2m, as well as bipodal [(Si-O-)2V(O)(OiPr)], 2b, formed along with (Si-O-iPr) 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 VO4 moieties [(Si-O-)3V(O)] (3) with formation of propylene whereas the (Si-O-iPr) 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.",

author = "H{\"o}gerl, {Manuel P.} and {Serena Goh}, {Li Min} and Edy Abou-Hamad and Samir Barman and Oliver Dachwald and Pasha, {Farhan Ahmad} and Jeremie Pelletier and Klaus K{\"o}hler and Valerio D'Elia and Luigi Cavallo and Basset, {Jean Marie}",

note = "Funding Information: This work was funded by King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. The authors declare no competing nancial interest. V. D. E. thanks the Thailand Research Fund (Grant No. RSA6080059) for funding this research. Publisher Copyright: {\textcopyright} 2018 The Royal Society of Chemistry.",

year = "2018",

doi = "10.1039/c8ra02419g",

language = "English",

volume = "8",

pages = "20801--20808",

journal = "RSC Advances",

issn = "2046-2069",

publisher = "Royal Society of Chemistry",

number = "37",

}

Högerl, MP, Serena Goh, LM, Abou-Hamad, E, Barman, S, Dachwald, O, Pasha, FA, Pelletier, J, Köhler, K, D'Elia, V, Cavallo, L & Basset, JM 2018, 'SOMC grafting of vanadium oxytriisopropoxide (VO(O^{: I}Pr)₃) on dehydroxylated silica; Analysis of surface complexes and thermal restructuring mechanism', RSC Advances, vol. 8, no. 37, pp. 20801-20808. https://doi.org/10.1039/c8ra02419g

TY - JOUR

T1 - SOMC grafting of vanadium oxytriisopropoxide (VO(O: IPr)3) on dehydroxylated silica; Analysis of surface complexes and thermal restructuring mechanism

AU - Högerl, Manuel P.

AU - Serena Goh, Li Min

AU - Abou-Hamad, Edy

AU - Barman, Samir

AU - Dachwald, Oliver

AU - Pasha, Farhan Ahmad

AU - Pelletier, Jeremie

AU - Köhler, Klaus

AU - D'Elia, Valerio

AU - Cavallo, Luigi

AU - Basset, Jean Marie

N1 - Funding Information: This work was funded by King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. The authors declare no competing nancial interest. V. D. E. thanks the Thailand Research Fund (Grant No. RSA6080059) for funding this research. Publisher Copyright: © 2018 The Royal Society of Chemistry.

PY - 2018

Y1 - 2018

N2 - Vanadium oxytriisopropoxide (VO(OiPr)3), 1, was grafted on highly dehydroxylated silica (SiO2-700: 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, 1H, 13C and 51V 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)(OiPr)2], 2m, as well as bipodal [(Si-O-)2V(O)(OiPr)], 2b, formed along with (Si-O-iPr) 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 VO4 moieties [(Si-O-)3V(O)] (3) with formation of propylene whereas the (Si-O-iPr) 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.

AB - Vanadium oxytriisopropoxide (VO(OiPr)3), 1, was grafted on highly dehydroxylated silica (SiO2-700: 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, 1H, 13C and 51V 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)(OiPr)2], 2m, as well as bipodal [(Si-O-)2V(O)(OiPr)], 2b, formed along with (Si-O-iPr) 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 VO4 moieties [(Si-O-)3V(O)] (3) with formation of propylene whereas the (Si-O-iPr) 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.

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U2 - 10.1039/c8ra02419g

DO - 10.1039/c8ra02419g

M3 - Article

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