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In this work we present the synthesis, characterization and molecular modeling of ICP-2, a new layered ferrierite precursor with expanded layers. ICP-2 is obtained in fluoride medium from aluminosilicate gels with low H 2 O content, using the chiral cation (1R,2S)-dimethylephedrinium (DMEP) as the organic structure-directing agent; ICP-2 can also be obtained as the Al-free form. The combination of physicochemical characterization of the material with molecular modeling indicates that ICP-2 is a layered material composed of ferrierite layers, where the organic cations play a dual 2 structural role through the formation of supramolecular aggregates. On the one hand, the organic cations stabilize the formation of the ferrierite layers with a core-shell structure, directing the formation of both the pseudo-10R channels (by supramolecular dimers aligned with the channel direction) and of the pseudo-cavities, with the trimethylammonium groups of DMEP fitting within. On the other hand, the aromatic rings of these organic cations in the pseudo-cavities develop π-π stacking interactions with equivalent cations in adjacent layers, holding together the ferrierite layers expanded at a distance of 20 Å, hence preventing the formation of H-bonds between the inorganic layers. The diastereoisomer (1S,2S)-dimethylpseudoephedrinium instead cannot direct the formation of ICP-2, which is explained because of its distinct conformational space which fits worse in the core-shell structure of ICP-2.

In this work we report a comparative study about the structure-directing effect of two chiral diastereoisomers, (1R,2S)-dimethyl-ephedrinium and (1S,2S)dimethyl-pseudoephedrinium, for the synthesis of nanoporous aluminophosphates. Both isomers direct the crystallization of the one-dimensional channels composing the AFI framework in the presence of divalent dopants when the crystallization temperature is moderate (140 ºC). An increase of the crystallization temperature (to 180 ºC) severely limits the structure-directing ability towards the AFI framework because of a poor hydrothermal stability of the organic cations, especially of the (1S,2S)-isomer. 13 C NMR and molecular simulations studies of these organic cations in solution and confined within nanoporous zeolitic materials allow us to clearly identify 13 C resonance signals of particular methyl groups which vary as a function of the conformational space, and enable us to monitor the occurrence of the different conformers in diverse environments. In vacuo and in solution, both organic cations display a conformation with an open-configuration, in which the bulky phenyl and trimethylammonium groups site in 'anti' configuration. Such conformational space is altered when the cations are confined within the limited space of the one-dimensional channels of the AFI structure. In this case, despite folded-conformations being intrinsically less stable, lateral packing interactions within the channels drive an incorporation of the cations as a mixture of conformers (with open-and folded-configurations) for the (1R,2S)-isomer or as folded conformers for the (1S,2S)-isomer, showing the importance of the conformational space of organic cations during the structure-directing phenomenon.

Mixed perovskites NaNbxTa1−xO3 were prepared by solid state reaction (SSR) as well as by hydrothermal (Hyd) methods, and their photocatalytic activity for hydrogen production was studied using the water–methanol system following Pt photodeposition.