A mesostructured silica/organic composite 1-MS, constructed from a rodlike micelle of amino acid amphiphile 1 that has a condensable head group and that can be used as a template, was found to be able to catalyze the acetalization of cyclohexanone, in ethanol at 25 degrees C (50% in 12 h), whereas no reaction took place with unfunctionalized mesoporous silica. In sharp contrast, hydrolytic removal of the C16 alkyl tail of immobilized 1 resulted in the complete disappearance of the catalytic activity, which suggests the importance of a hydrophobic inner domain for the admission of cyclohexanone. Unsupported peptide amphiphile 2, under identical conditions to those above, was inefficient for acetalization regardless of the absence (2% in 24 h) or presence of mesoporous silica (7% in 24 h). Reference composite 2-MS, which is a noncovalently immobilized peptidic micelle, was virtually inactive (1% in 24 h). These observations indicate the importance of covalent immobilization of the peptidic rod micelle for catalysis. Mesostructured silicate 3-MS hybridized with a nonpeptidic, ammonium ion amphiphile (3) showed a certain catalytic activity, but the yield (12% in 24 h) of the acetal was much lower than that achieved by using 1-MS as the catalyst. Amorphous silica with immobilized 1 on its surface was much less active than 1-MS for acetalization (5% in 24 h).

A bipyridine-based ligand 1 bearing two amphiphilic side chains allowed for the formation of metal complexes Pt(1)Cl2 (2), [Pt(1)2](BF4)2 (3), and [Pt(1)2][Pt(CN)4] (4), which are capable of templating the sol-gel synthesis of mesostrucutred silica to give 2-MS, 3-MS and 4-MS, respectively, whose silicate channels are filled with the corresponding platinum complexes. In particular, silica composite 4-MS, upon spin-coating, gives a transparent film, which emits at 619 nm upon excitation at 495 nm, indicating that a weak Pt--Pt bond, formed between Pt(1)2(2+) and Pt(CN)4(2-) via a metallophilic interaction, is successfully incorporated into the silicate nanochannels.