Alkali metal organocyclotrisiloxanolates [RSi(O)OM]3 with vinyl and alkyl substituents at the silicon center

Well-defined cyclic silanol derivatives

“…Later, a set of new sodium ethyl-, propyl-substituted and potassium vinyl-, methyl-substituted cis,cis-T 3 were synthesized using a similar synthetic method (Table 3, 13-16). 60 All these compounds possess comparable crystal structures with the abovementioned 11 and 12 and despite the organic substituent R, they all show a boat conformation of sixmembered siloxane cores, which indicates that the nature of R hardly affects the geometry of these trisiloxanolate rings.…”

“…78 In 2010, Laine et al described the synthesis of tetraaryl-substituted sodium all-cis-cyclotetrasiloxanolates (33 and 43) from cubic polyhedral oligosilsesquioxanes (POSSs, Scheme 11). Compound 33 was used to react with three trichloroorganosilanes (YSiCl 3 ) to produce all-cis-T 4 (58)(59)(60). Compound 58 was then hydrolyzed by hydrochloric acid to afford a Janus cube.…”

Carborane–Siloxanes: Synthesis and Properties. New Possibilities for Structure Control

“…In particular, along with the cubic carborane-containing structures, cyclosiloxanes can be considered as promising molecular fillers. The synthesis of these compounds was carried out using individual organometallosiloxanes [86][87][88][89][90][91][92][93][94][95][96][97][98][99]; investigations on their synthesis and properties are actively developed at the Laboratory of Organosilicon Compounds, INEOS RAS.…”

Alkali-Metal-Directed Hydrolytic Condensation of 3-Mercaptopropyltrimethoxysilane

“…The most popular method for preparation of cyclic siloxane monomers is hydrolytic condensation of trialkoxyorganosilanes (Scheme 1) in the presence of water and an alkali metal hydroxide. It was found that properties of metal cations can influence the structure of the formed moieties since they work as template centers and structural elements helping to bind siloxane bonds into cyclic organosiloxanolate fragments [20][21][22][23][24][25][26][27][28][29][30][31][32]. While transition or rare-earth metal cations lead to the formation of varied-size (n=4 [20], 5 [21], 6, 8, 12 [22][23][24]) cyclic species, sodium and potassium cations enable the synthesis of small cyclosiloxanes containing three [25][26][27][28] or four [29][30][31] silicon atoms.…”

“…While transition or rare-earth metal cations lead to the formation of varied-size (n=4 [20], 5 [21], 6, 8, 12 [22][23][24]) cyclic species, sodium and potassium cations enable the synthesis of small cyclosiloxanes containing three [25][26][27][28] or four [29][30][31] silicon atoms. Reaction parameters (the amount of water, type of organosilane and solvent) also can affect the ring size of cyclic products [32].…”