Covalent post-synthetic modification

In contrast to these post-synthetic modifications, it is also possible to functionalize the pore walls directly during the synthesis, as was first shown by Mann and co-workers [7,8] and Stucky and coworkers [9], who used trialkoxysilanes R-Si(OR )3. In our approach, such R Si(OR )3 molecules substitute for part of the TEOS. After hydrolysis, they serve as additional framework components during the hydrothermally induced condensation. An essential condition for this approach is that the trialkoxysilane does not destroy the micellar arrangement of the surfactant, which gives rise to the mesostructure. In mesostructures produced in this way, the R residues should be covalently linked to the silica walls. After the synthesis, the organic surfactant molecules can be removed by extraction so that a modified mesoporous material should remain. For example, when using phenyltrimethoxysilane (PTMOS), phenyl groups may become attached to the walls of the mesopores these can be utilized for further modifications, e.g. the immobilization of metal complexes. 

Covalently Bound Redox Systems via Post-Synthetic Modification. A... 

Self-assembly with post-modification. The most common form of modification that is utilised in synthetic systems is the alteration of a system after the self-assembly step has taken place. Many common systems, such as rotaxanes and catenanes (Section 3.4), are formed from a self-assembled structure, held loosely together by non-covalent interactions, which are locked in place once the self-assembly process is complete by the formation of covalent bonds, much like tying off the ends of a knot. 

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