Fascinating chiral information transfer to titania/silica from near to racemic compound self-organized from polyethyleneimine and tartaric acid

In this work, chiroptical crystalline complexes of PEI/Tart (P/T) consisting of linear poly(ethylemeimine) (PEI) and an enantiomeric excess (ee) of tartaric acid (Tart) were used as chiral catalytic templates in the hydrolytic condensation of titanium bislactates and co-condensation of titanium bislactates and tetramethoxysilane for the preparation of chiral titania (TiO 2 ) and chiral titania/silica (TiO 2 /SiO 2 ) hybrid. Different from the general case of enantiopure templates excelling in chiral transformation when compared to enantiomeric excess ones, P/T systems with different enantiomer ratios exhibited each activity in the transformation of their chiral information to the resulting minerals titania and titania/silica. Especially, the P/T complexes with ee only by ±4% ( d / l = 52/48 or 48/52), which is near the racemic state ( d / l = 50/50), served as excellent chiral catalytic templates to generate chiroptical titania and titania/silica with mirror relation of the CD signals. By means of DSC, XRD, SEM and DRCD techniques, the crystalline complexes of PEI/Tart (P/T), the as-prepared TiO 2 @P/T and TiO 2 /SiO 2 @P/T, and the calcined TiO 2 and TiO 2 /SiO 2 were thoroughly investigated and the mechanism of the chiral transformation from the enantiomeric excess of P/T to minerals was proposed. Crystalline aggregates (P/T) self-organized from polyethyleneimine (P) and enantiomeric excess (ee = ±4%, d / l = 52/48 and 48/52) of tartaric acid (T) could serve as chiral catalytic templates to effectively give chiroptical hybrids of TiO 2 /SiO 2 .