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• 10360-75-5 1,3,5,7-tetraphenylcyclotetrasiloxane 

Relevant academic research and scientific papers

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

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.

A asymmetric cage polyhedral oligomeric silsesquioxane synthetic method and application

The invention relates to the technical field of synthesis of polyhedral low oligomeric silsesquioxane, and solves the problems of irregular distribution of functional groups and complicated purification process of the product in existing synthesis of the asymmetric cage-shaped polyhedral low oligomeric silsesquioxane. The synthetic method of the asymmetric cage-shaped polyhedral low oligomeric silsesquioxane comprises the steps that a reaction on isotactic-cyclotetrasiloxane shown in a structural formula (II) and isotactic-cyclotetrasiloxane tetrasilanol shown in a structural formula (III) which are used as raw materials are carried out in an organic solvent under a function of a catalyst, and the raw materials are subjected to post-treatment so as to obtain the asymmetric cage-shaped polyhedral low oligomeric silsesquioxane shown in the structural formula (I). The synthetic method has the advantages of mild reaction conditions, low energy consumption, high synthetic efficiency, simple purification process of the product, feasibility and the like. The reaction process is shown in the description.

Synthesis, functionalization and properties of incompletely condensed half cube silsesquioxanes as a potential route to nanoscale Janus particles

Multiple literature reports describe the synthesis of [RSiO(OH)]4 or [RSiO(ONa)]4 compounds. Surprisingly, in the majority of cases the OH or ONa groups all lie on the same face of the cyclomers or half cubes. Consequently, it appears possible to couple R containing half cubes with R' containing half cubes to form bi-functional (Janus) silsesquioxane cages or cubes. We report here synthesis of [PhSiO(ONa)]4 and [p-IPhSiO(ONa)]4 half cubes. We thereafter discuss efforts to react the [PhSiO(ONa)]4 salt with (R = Me, vinyl, and cyclohexyl) RSiCl3 in MeOH to produce the compounds {PhSiO[OSi(OMe)2R]}4 species which were characterized using traditional spectroscopic procedures. These compounds were then subjected to acid catalyzed hydrolysis tohydrolytically remove the OMe groups to generate Janus cubes. While it is possible to isolate the target compounds, which were also characterized in detail, the yields were lower than expected perhaps because of competitive hydrolytic cleavage of the Si-O-SiR(OMe)2 linkage.