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Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols
We have drawn a few interesting conclusions while studying reaction products of Ph(2)Si(OH)(2) with Al((i)Bu)(3) and tetraisobutylalumoxane. In the first place, this is the production (at a Ph(2)Si(OH)(2) and Al((i)Bu)(3) equimolar ratio) of an oligomer siloxyalumoxane structure with alternating fou...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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MDPI
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6151760/ https://www.ncbi.nlm.nih.gov/pubmed/29053617 http://dx.doi.org/10.3390/molecules22101776 |
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author | Shcherbakova, Galina Storozhenko, Pavel Kisin, Alexander |
author_facet | Shcherbakova, Galina Storozhenko, Pavel Kisin, Alexander |
author_sort | Shcherbakova, Galina |
collection | PubMed |
description | We have drawn a few interesting conclusions while studying reaction products of Ph(2)Si(OH)(2) with Al((i)Bu)(3) and tetraisobutylalumoxane. In the first place, this is the production (at a Ph(2)Si(OH)(2) and Al((i)Bu)(3) equimolar ratio) of an oligomer siloxyalumoxane structure with alternating four- and six-member rings. In addition, it shows isobutyl and phenyl group migration between aluminum and silicon due to the formation of an intramolecular four-member cyclic complex [Ph(2)(OH)SiO]Al((i)Bu)(2) → [((i)Bu)Ph(OH)SiO]Al((i)Bu)Ph. Ph(2)Si(OH)(2) interaction with Al((i)Bu)(3) not only starts from intramolecular complex production, but the chain is terminated for the same reason, which in the case of the Ph(2)Si(OH)(2) reaction with tetraisobutylalumoxane results in failure of to obtain high-polymer siloxyalumoxane compounds. When Al((i)Bu)(3) interacts with α- and γ-diols, no oligomer compounds are produced. In the Al((i)Bu)(3) reaction with α, γ-diols are created in monomer compounds that are likely to have a cyclic structure. Notably, when Al((i)Bu)(3) interacts with only α-diol, a double excess of Al((i)Bu)(3) allows for full replacement of hydrogen in the α-diol hydroxyl groups by aluminum alkyl residue with 1,3-bis(diisobutylalumoxymethyl)-1,1,3,3-tetramethyldisiloxane production. At an equimolar ratio of initial reagents, the second isobutyl radical at Al does not interact with the second hydroxyl group of α-diol, apparently due to the steric hindrance, and 1-(diisobutylalumoxymethyl)-3-(hydroxymethyl)-1,1,3,3-tetramethyl-disiloxane is produced. Al((i)Bu)(3) reactions with γ-diol also result in monomer compounds, but the presence of a chain consisting of three CH(2)-groups between Si and the hydroxyl group facilitates interaction between the second hydroxyl group of γ-diol and the second isobutyl radical Al((i)Bu)(3). Tetraisobutylalumoxane reactions with α- and γ-diols result in oligomer compounds. |
format | Online Article Text |
id | pubmed-6151760 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-61517602018-11-13 Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols Shcherbakova, Galina Storozhenko, Pavel Kisin, Alexander Molecules Article We have drawn a few interesting conclusions while studying reaction products of Ph(2)Si(OH)(2) with Al((i)Bu)(3) and tetraisobutylalumoxane. In the first place, this is the production (at a Ph(2)Si(OH)(2) and Al((i)Bu)(3) equimolar ratio) of an oligomer siloxyalumoxane structure with alternating four- and six-member rings. In addition, it shows isobutyl and phenyl group migration between aluminum and silicon due to the formation of an intramolecular four-member cyclic complex [Ph(2)(OH)SiO]Al((i)Bu)(2) → [((i)Bu)Ph(OH)SiO]Al((i)Bu)Ph. Ph(2)Si(OH)(2) interaction with Al((i)Bu)(3) not only starts from intramolecular complex production, but the chain is terminated for the same reason, which in the case of the Ph(2)Si(OH)(2) reaction with tetraisobutylalumoxane results in failure of to obtain high-polymer siloxyalumoxane compounds. When Al((i)Bu)(3) interacts with α- and γ-diols, no oligomer compounds are produced. In the Al((i)Bu)(3) reaction with α, γ-diols are created in monomer compounds that are likely to have a cyclic structure. Notably, when Al((i)Bu)(3) interacts with only α-diol, a double excess of Al((i)Bu)(3) allows for full replacement of hydrogen in the α-diol hydroxyl groups by aluminum alkyl residue with 1,3-bis(diisobutylalumoxymethyl)-1,1,3,3-tetramethyldisiloxane production. At an equimolar ratio of initial reagents, the second isobutyl radical at Al does not interact with the second hydroxyl group of α-diol, apparently due to the steric hindrance, and 1-(diisobutylalumoxymethyl)-3-(hydroxymethyl)-1,1,3,3-tetramethyl-disiloxane is produced. Al((i)Bu)(3) reactions with γ-diol also result in monomer compounds, but the presence of a chain consisting of three CH(2)-groups between Si and the hydroxyl group facilitates interaction between the second hydroxyl group of γ-diol and the second isobutyl radical Al((i)Bu)(3). Tetraisobutylalumoxane reactions with α- and γ-diols result in oligomer compounds. MDPI 2017-10-20 /pmc/articles/PMC6151760/ /pubmed/29053617 http://dx.doi.org/10.3390/molecules22101776 Text en © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Shcherbakova, Galina Storozhenko, Pavel Kisin, Alexander Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols |
title | Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols |
title_full | Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols |
title_fullStr | Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols |
title_full_unstemmed | Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols |
title_short | Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols |
title_sort | synthesis of siloxyalumoxanes and alumosiloxanes based on organosilicon diols |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6151760/ https://www.ncbi.nlm.nih.gov/pubmed/29053617 http://dx.doi.org/10.3390/molecules22101776 |
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