On the polycondensation products of cis-(1,3,5,7-tetrahydroxy)-1,3,5,7-tetraphenylcyclo-tetrasiloxane

Андрианов, К. А.; Tverdokhlebova, I.I.; Макарова, Н. Н.; Mamayeva, I.I.; Chekalov, A. K.; Men’shov, V. M.; Pavlova, S.-S.A.

doi:10.1016/0032-3950(78)90055-2

Cited by 8 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Removal of metal ions from cyclic tetrametallasiloxanes by dilute aqueous hydrochloric acid is a convenient preparative method resulting in high-yield (80-90 %) formation of stereoregular oligophenysiloxane polyols: all-cis-[PhSi(OH)O] 4 12 [27]. Analogously,1,3,5,7-tetramethyl-1,3,5,7-tetrahydroxy-cyclo tetrasiloxane was obtained from all-cis-(tetrapotassium tetramethylcyclotetrasiloxanolate) (K + ) 4 [28].…”

Section: Monomer Synthesis and Polycondensationmentioning

confidence: 99%

“…Polysilsesquioxanes can be also obtained by condensation of specific tetrasiloxane precursors such as disiloxanes [RSiX 2 ] 2 O and cyclotetrasiloxanes [RXSiO] 4 that help the formation of a true ladder structure. Linear ladder silsesquioxanes have been synthesized from sila-functionalized [RSiXO] 4 (R = Me, Ph; X = H, OEt, NCO) [11,12]. Polycondensation of all-cis or cis-trans-cis isomers of cyclic tetrasilanols [13] or isocyanates [14] gives linear polymers of high regularity and defined tacticity.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Ladder Silsesquioxanes by in situ Polycondensation of Cyclic Tetravinylsiloxanetetraols

Kowalewska

Nowacka

2014

Silicon

View full text Add to dashboard Cite

Functionalized tetrahydroxy-cyclotetrasiloxanes are very attractive precursors of tetrasiloxane ring systems in linear silsesquioxanes (LPSQs). Vinyl groups are especially important since they can be employed for various chemical transformations (e.g. hydrosilylation, metathesis reactions, thiol-ene addition). However, isolation of such highly reactive species bearing small side substituents at silicon atoms with high yield is challenging. We overcame the problem by in situ condensation of 2,4,6,8-tetrahydroxy-2,4,6,8-tetravinyl-cyclotetrasiloxanes, derived from potassium organosiloxanolateOligomeric LPSQ materials having a siloxane backbone with ladder structure and functionalized with side vinyl groups were thus prepared. Hexamethyldisilazane was employed for chain termination. The liquid materials show remarkably good solubility in organic solvents. They were isolated and characterized using spectroscopic methods. Information on their structure and molecular masses was derived from MALDI-TOF and MALLS measurements. Size exclusion chromatography (RI detection, volume of elution measurements) was also used. The products were characterized by wide-angle X-Ray diffraction measurements (WAXS) and their thermal characteristics (TGA and DSC) were obtained.

show abstract

Section: Monomer Synthesis and Polycondensationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis of Ladder Silsesquioxanes by in situ Polycondensation of Cyclic Tetravinylsiloxanetetraols

Kowalewska

Nowacka

2014

Silicon

View full text Add to dashboard Cite

show abstract

“…It has been shown by the synthesis of 4A and 4B that a Janus cube with Si−OH groups (Ph 4 (HO) 4 Si 8 O 12 ) is present in the solution prior to silylation. Controlled intermolecular polycondensation of Ph 4 (HO) 4 Si 8 O 12 will enable the production of a new ladder‐like polysiloxane in a similar manner to the synthesis of laddersiloxanes from cyclotetrasiloxanes (see Figure S21) . In addition, when Ph 4 (HO) 4 Si 8 O 12 is silylated with alkoxy(chloro)silanes and subjected to further intramolecular condensation, stepwise extension of the cage structure can be expected (see Figure S22).…”

Section: Resultsmentioning

confidence: 99%

“…Controlled intermolecular polycondensation of Ph 4 (HO) 4 Si 8 O 12 will enable the production of an ew ladder-like polysiloxane in as imilar manner to the synthesis of laddersiloxanes from cyclotetrasiloxanes (see Figure S21). [45,46] In addition, when Ph 4 (HO) 4 Si 8 O 12 is silylated with alkoxy(chloro)silanes and subjected to furtheri ntramolecular condensation, stepwise extension of the cage structure can be expected (see Figure S22). Please note that the feasibility of formation of such interesting structures may be low because of the strain of the bond angles.…”

Section: Validity Of the Hydrolysisand Intramolecular Condensation Rementioning

confidence: 99%

Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes

Sugiyama

Shiba

Yoshikawa

et al. 2019

Chemistry A European J

View full text Add to dashboard Cite

The controlled synthesis of oligosiloxanes with well‐defined structures is important for the bottom‐up design of siloxane‐based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra‐ and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy‐ and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So‐called Janus cubes have been successfully obtained, that is, Ph4R4Si8O12, in which R=Me, OSiMe3, and OSiMe2Vi (Vi=vinyl). These findings will enable the creation of siloxane‐based materials with diverse functions.

show abstract

“…This indicates that steric parameters of a monomer can substantially affect the results of polymerization or polycondensation processes of organocyclosiloxanes. Due to the hydrodynamic and electro-optical characteristics of LPPSSO solutions, the differences in the α-values in the Mark–Kuhn–Houwink equation and the Kuhn segment were revealed depending on the ladder polymer structure, production method, organic substituents at the silicon atoms, and the structure of the prepolymer [ 6 , 7 , 8 , 9 ]. Despite the fact that 50 years have passed, interest in the steric characteristics of the polymers, these hybrid CL LPPSSO and other CL ladder polyorganosilsesquioxanes (LPOSSO), persists.…”

Section: Introductionmentioning

confidence: 99%

A Study of the Polycondensation of (Tetrahydroxy)(Tetraaryl)Cyclotetrasiloxanes under Equilibrium and Non-Equilibrium Conditions in the Presence and Absence of Montmorillonite

et al. 2018

View full text Add to dashboard Cite

Oligo- and polycyclosiloxanes were obtained by the polycondensation of (tetrahydroxy)(tetraaryl)cyclotetrasiloxanes in equilibrium and non-equilibrium conditions in the presence and absence of montmorillonite (MMT). Their composition and the structures of their components were investigated by infrared (IR) spectroscopy, 29Si nuclear magnetic resonance (NMR) spectroscopy, atmospheric pressure chemical ionization (APCI) mass spectrometry, powder X-ray diffraction (XRD), and gel-penetrating chromatography (GPC). Also, a comparison of polymers formed in the presence of MMT and via anionic polymerization was performed showing differences in their structures.

show abstract

On the polycondensation products of cis-(1,3,5,7-tetrahydroxy)-1,3,5,7-tetraphenylcyclo-tetrasiloxane

Cited by 8 publications

References 7 publications

Synthesis of Ladder Silsesquioxanes by in situ Polycondensation of Cyclic Tetravinylsiloxanetetraols

Synthesis of Ladder Silsesquioxanes by in situ Polycondensation of Cyclic Tetravinylsiloxanetetraols

Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes

A Study of the Polycondensation of (Tetrahydroxy)(Tetraaryl)Cyclotetrasiloxanes under Equilibrium and Non-Equilibrium Conditions in the Presence and Absence of Montmorillonite

Contact Info

Product

Resources

About