Ceramics and Nanostructures from Molecular Precursors

Abstract

The elaboration of solids from the molecular scale by a kinetically controlled methodology is one of the main challenges of molecular chemistry. In the long term, this should permit the design of solids with desired properties. Here, some examples are given which show a few methods that have been used for the preparation of solids from molecular precursors. The one-pot synthesis of rheologically controlled SiC is described. Access to a new kind of ceramic is obtained by the same methodology using molecular precursors. Mixed ceramics with interpenetrating networks are not accessible by the chemical thermodynamic route. The chemistry of hybrid materials obtained from molecular precursors through inorganic polymerization is presented. This class of materials offers wide perspectives because of 1) the large possibilities opened by the organic unit, 2) the kinetic control, which permits any kind of texture for the solid, and 3) the aptitude of these solids to become nanostructured.

Highly Fluorescent Mesostructured Films that consist of Oligo(phenylenevinylene)–Silica Hybrid Frameworks

“…[3] These organic-modified mesoporous silicas are useful as functional materials because mesoscale porous structures and molecular-scale functionalities based on organic species can be cooperatively utilized to construct various systems such as solid-state catalysts, drugdelivery systems, and dye-doped energy-transfer schemes. [3][4][5][6] Since the development of bridged organosilane precursors ((R 0 O) 3 Si-R-Si(OR 0 ) 3 ) in the 1990s, [7,8] periodic mesoporous organosilicas (PMOs), in which organic bridging groups (-R-) are embedded within robust silica pore walls, have been focused on as promising candidates for novel high-performance and high-functionality inorganic-organic hybrids. [9,10] Introduction of aromatic and p-conjugated organic bridging groups into the pore walls has further widened the applications of mesoporous organosilica hybrids.…”

Designed synthesis of nanostructured siloxane–organic hybrids from amphiphilic silicon-based precursors

“…5,6 The chemical design of organosilanes at the molecular scale leads to modifications of the structures and properties of hybrids. However, the products are generally amorphous solids, and control of their nanostructure is one of the most important subjects with respect to the creation of advanced materials.…”

Structural Evolution of Self‐Assembling Nanohybrid Thin Films from Functionalized Urea Precursors

“…In this context, organo-bridged di-silanes, (EtO) 3 Si-R-Si(OEt) 3 , are potentially useful candidates for preparing multifunctional thin films, based on their widespread use in the preparation of bulk silsesquioxanes [5,6] for a variety of applications. [7][8][9][10] In particular, we have previously reported a synthetic approach for preparing hybrid materials with controlled porosities, [11] and for solid-liquid phase extraction of lanthanides and actinides [12] . In addition, there have been many reports of sol-gel strategies for preparing amorphous, bulk hybrid materials as recyclable and efficient heterogeneous catalysts for several types of organometallic reactions [13][14][15] including asymmetric reduction of prochiral ketones, [13] Suzuki cross-coupling reactions [14a] and Hoveyda-Grubbs ring closure metathesis reactions.…”