Polysilanols

Lickiss, Paul D.

doi:10.1002/9780470682531.pat0246

Cited by 4 publications

(6 citation statements)

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“…Despite the recent remarkable progress of catalytic synthesis, siloxane bonds are formed via the condensation of silanols generated from chlorosilane hydrolysis in the general industrial process, and chlorosilane is the most common starting material for the synthesis of polycyclic silsesquioxanes and other siloxane compounds . In addition, chlorosilane directly reacts with alkoxysilane, silanol, and siloxanolate to afford siloxane bonds and various byproducts including alkyl chloride, hydrochloric acid, and sodium chloride.…”

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confidence: 99%

Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane

et al. 2019

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A novel synthetic method for the construction of a double-decker silsesquioxane from fluorosilanes was developed. Phenyl-substituted double-decker silsesquioxane was prepared under mild conditions by coupling difluorodiphenylsilane and a tetrasiloxanolate precursor. A similar reaction was performed using difluorovinylsilane, and a divinyl double-decker silsesquioxane was obtained. The one-step reaction of a functional difluorosilane containing an aminopropyl group afforded a novel double-decker silsesquioxane with two amino groups complexed with BF3, which can react with carboxylic acid anhydrides to afford an amide product. This synthetic method using difluorosilane is tolerant of a wide range of functional groups and is applicable to the synthesis of polycyclic silsesquioxanes bearing amino groups, which are difficult to directly obtain from dichlorosilane.

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confidence: 99%

Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane

et al. 2019

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“…Similar geometrical parameters around the silicon would be expected at each monomer unit of the polymer. Generally, chlorosilanes are very sensitive to moisture and undergo a hydrolysis–condensation to give water silicon coordination (Si←OH 2 ), which further condenses into siloxanes (Si–O–Si). , …”

Section: Hydrolysis–condensation Studies By X-ray Crystallographymentioning

confidence: 99%

“…9,11 These species have one or more −OH groups per structural unit and can form ladder-type, open, and linear structures. 5,12,13 Chlorosilane compounds have also been utilized in condensation reactions, in some cases to replace alkoxysilane compounds, due to the relatively high reactivity of the Si−Cl bond toward Si−O− Si bond formation. 14−17 In contrast to carbon, silicon displays the ability to form hydrolyzable hypercoordinate silicon species with five, six, and seven substituents.…”

Section: Introductionmentioning

confidence: 99%

“…Monoorganosilanes in common use have one organic nonhydrolyzable group and three hydrolyzable substituents, R-Si(OR) 3 or R-SiCl 3 . − The hydrolysis of alkoxy silanes into silanols (Si–OH) and polycondensation into siloxanes (Si–O–Si) containing a nonhydrolyzable Si–R group leads to a variety of silsesquioxanes with various ladder network and cage-like structures. , Fully condensed silsesquioxanes have been synthesized and characterized as cage structures including a few examples of host–guest species 1 . Incompletely condensed structures containing Si–OH groups are also known. , These species have one or more −OH groups per structural unit and can form ladder-type, open, and linear structures. ,, Chlorosilane compounds have also been utilized in condensation reactions, in some cases to replace alkoxysilane compounds, due to the relatively high reactivity of the Si–Cl bond toward Si–O–Si bond formation. − …”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Hydrolysis–Condensation Study of Water-Soluble Self-Assembled Pentacoordinate Polysilylamides

et al. 2013

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Polysilylamides (n = 1−8) with a Si−Cl functionality containing pentacoordinate silicon in the backbone were produced in high yield by transsilylation of bis(chloromethyl)methylchlorosilane and the trimethylsilyl derivative of diketopiperazine. Pentacoordinate polysilylamides were highly soluble in water as a result of silicon water coordination (Si←OH 2 ) from hydrolysis of the Si−Cl group in each repeat unit. Interestingly, the water silicon coordination in polysilanolamides was stable toward self-condensation and found to contain pentacoordinate silicon even in water, thus avoiding siloxane (Si−O−Si) bond formation. In the gas phase the polysilanolamides underwent intramolecular stepwise hydrolysis−condensation possibly as a result of CC double-bond formation at each monomer unit, as observed by MALDI-TOF MS. Low-intensity peaks of macrocyclic polysilanolamides (n = 2−5) were also observed that contain water molecules. For a better understanding of the hydrolysis−condensation process of the polysilylamide, new model compounds of pentacoordinated silicon derivatives of pyridones were synthesized, characterized, and compared with the polysilanolamides using NMR and X-ray crystallography. X-ray analysis of the model compounds revealed insight into the silicon water coordination in each repeat unit and the mode of packing within the polymers that contain these monomer units. It is found that the partial hydrolysis of the model pentacoordinate chlorosilanes gives water-coordinated pentacoordinate silicon species that resemble an intermediate in the aqueous hydrolysis of pentacoordinate polysilylamides.

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“… They are useful in gathering spectroscopic signatures of possible surface species and to better understand the specificity of surface bound species, with the ultimate goal to obtain structure–property relationships. The most typical examples are tris‐alkyl/aryl and tris‐alkylsilanols (‐OSiR 3 ), trialkoxysilanols (‐OSi(OR) 3 ), or polyhedral oligomeric silsesquioxane (POSS) ligands. Each family provides a different environment and offers specific advantages .…”

Section: Introductionmentioning

confidence: 99%

Facile Synthesis of Unsymmetrical Trialkoxysilanols: (RO)₂(R′O)SiOH

Docherty

Estes

Copéret

2018

Helvetica Chimica Acta

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Trialkoxysilanols, (RO)3SiOH, are useful as ligands in transition‐metal complexes because they provide models for silica‐supported metal sites or precursors for the thermolytic precursor approach. However, their synthesis is mostly limited to symmetrical ones, where all RO ligands are the same. However, unsymmetrically substituted trialkoxysilanols could offer significant advantages over their symmetrical counterparts by facilitating crystallization of complexes, lowering crystallographic disorder, changing the thermal properties of the complexes made, and making the addition of pendant functional groups possible. Herein, a simple, general synthetic procedure yielding unsymmetrical trialkoxysilanols (RO)2(R′O)SiOH is presented using imidazole as a promoter.

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Polysilanols

Abstract: Introduction Synthesis of Polysilanols Reactions of Polysilanols Structural Studies of Silanols Conclusions Acknowledgements

Cited by 4 publications

References 238 publications

Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane

Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane

Synthesis and Hydrolysis–Condensation Study of Water-Soluble Self-Assembled Pentacoordinate Polysilylamides

Facile Synthesis of Unsymmetrical Trialkoxysilanols: (RO)₂(R′O)SiOH

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Polysilanols

Abstract: Introduction Synthesis of Polysilanols Reactions of Polysilanols Structural Studies of Silanols Conclusions Acknowledgements

Cited by 4 publications

References 238 publications

Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane

Synthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane

Synthesis and Hydrolysis–Condensation Study of Water-Soluble Self-Assembled Pentacoordinate Polysilylamides

Facile Synthesis of Unsymmetrical Trialkoxysilanols: (RO)2(R′O)SiOH

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Facile Synthesis of Unsymmetrical Trialkoxysilanols: (RO)₂(R′O)SiOH