Structure Directing Effect of (1S,2S)-2-Hydroxymethyl-1-benzyl-1-methylpyrrolidinium in the Synthesis of AlPO-5

Abstract

A pure diastereoisomer of a new chiral organic molecule with two asymmetric atoms, (1S, 2S)-2-hydroxymethyl-1-benzyl-1-methylpyrrolidinium, has been prepared and used as structure directing agent (SDA) for the crystallization of the one-dimensional AlPO-5 microporous aluminophosphate. Our main objective is to induce chiral supramolecular arrangements of the SDA molecules within the microporous structure. The SDA molecules can be arranged as monomers or dimers within the nanochannels of AlPO-5, the aggregation being driven by π−π type interactions between the aromatic rings. It has been found that increasing the crystallization time leads to a higher organic content (and lower water incorporation) together with a higher formation of dimers, which indicates that the incorporation of the organic molecules as dimers is thermodynamically favored. We also observe a partially reversible photoinduced rearrangement of the SDAs; the aggregation is enhanced by exciting the occluded monomers with the appropriate wave...