A Porous POSiSil Suited for Pressure-Driven Reversible Confinement of Solutions: PSS-2.

Polyoligosiloxysilicone (POSiSil; designated PSS-2) is a copolymer of double four-ring (D4R) cyclosilicate and dimethylsiloxane. It is synthesized by linking D4R units in tetrabutylammonium cyclosilicate crystals with dimethyldichlorosilane. The structure of PSS-2 was revealed using solid state NMR spectroscopy.

Solid-state NMR tools for the structural characterization of POSiSils: Si sensitivity improvement with MC-CP and 2D Si- Si DQ-SQ at natural abundance.

The H- Si multiple-contact cross polarization (MC-CP) MAS NMR experiment is evaluated for the class of silicate-siloxane copolymers called POSiSils, that is, polyoligosiloxysilicones. It proves a reasonably good solution to tackle the challenge of recording quantitative Si NMR data in experimental time much reduced compared with single pulse acquisition. In a second time, we report Si- Si MC-CP double-quantum single-quantum (MC-CP-DQ-SQ) NMR experiment, which provides information about the through-space proximities between all silicon species despite the high degree of heterogeneity of this material.

Alternating Copolymer of Double Four Ring Silicate and Dimethyl Silicone Monomer-PSS-1.

A new copolymer consisting of double four ring (D4R) silicate units linked by dimethylsilicone monomer referred to as polyoligosiloxysilicone number one (PSS-1) was synthesized. The D4R building unit is provided by hexamethyleneimine cyclosilicate hydrate crystals, which were dehydrated and reacted with dichlorodimethylsilane. The local structure of D4R silicate units and dimethyl silicone monomers was revealed by multidimensional solid-state NMR, FTIR and modeling.

Hexakis(adamantyltrimethylammonium) cyclooctasilicate tetratetracontahydrate.

The title compound, 6C(13)H(24)N(+)·H(2)Si(8)O(20)(6-)·44H(2)O, belongs to the class of cyclosilicate hydrates, which structurally can be positioned between the zeosils and the clathrate hydrates. [Si(8)O(18)(OH)(2)] cubes carrying six negative charges are located on crystallographic inversion centres and are surrounded by six adamantyltrimethylammonium cations.

Synthesis of highly stable pure-silica thin-walled hexagonally ordered mesoporous material.

Hexagonally ordered mesoporous silica with a very narrow mesopore size distribution and exceptionally high stability paired with unusually thin pore walls was prepared using piperidine and cetyltrimethylammonium bromide.