Synthesis and structural characterization of trans-tactic siloxylene-vinylene-p-phenylene polymers via ADMET copolymerization and silylative coupling (SC) polycondensation
作者:Bogdan Marciniec、Mariusz Majchrzak
DOI:10.1016/s0022-328x(03)00667-3
日期:2003.11
The first trans-tactic stereo-regular vinylene-siloxylene-p-phenylene copolymer I with perfect vinylsiloxane linkage was obtained via acyclic diene metathesis copolymerization of divinyltetraethoxydisiloxane with 1,4-divinylbenzene (DVB) in the presence of Grubbs catalyst. The similar trans-tactic copolymers 2 and 3 but with no consecutive vinylsiloxane linkage was also prepared by silylative coupling copolycondensation of DVB with divinyltetra(methyl,ethoxy)disiloxane catalyzed by [Ru(H)(Cl)(CO)(PCy3)(2)]. (C) 2003 Elsevier B.V. All rights reserved.
Molecularly Ordered Nanoporous Organosilicates Prepared with and without Surfactants
作者:Abdelhamid Sayari、Wenhui Wang
DOI:10.1021/ja054103z
日期:2005.9.1
The first example of pure periodic mesoporous organosilica (O3/2Si-CH=CH-C6H4-CH=CH-SiO3/2) containing aromatic and olefinic functional groups was synthesized using a single precursor. In addition to the long-range order of the pore system, this material exhibited a structural periodicity with a spacing of 11.9 A due to the formation of lamellar bis(ethen-2-yl)benzene silica within the pore walls. It was also demonstrated that the molecular order can be achieved regardless of the occurrence of a periodic pore system or the use of surfactants.
Structural Changes of Hierarchically Nanoporous Organosilica/Silica Hybrid Materials by Pseudomorphic Transformation
affects both organosilica and silica phases and pseudomorphic transformation induces phase transition. A double‐layer structure of separate organosilica and silica layers is established for the impregnated material, while a single monophase consisting of randomly distributed T and Q silicon species at the molecular level is identified for the pseudomorphic transformed materials.