The Effect of Solution Conditions on the Driving Forces for Self-Assembly of a Pyrene Molecule

5 years ago

The Effect of Solution Conditions on the Driving Forces for Self-Assembly of a Pyrene Molecule

Shaowei Shi, Dapeng Liu, Xiaosong Wang

Fe(CO){CO(CH2)5CH2-pyrene}(Cp)(PPh3) (Fp-pyrene) is soluble in DMSO and THF, but insoluble in water, methanol, and ethanol. The hydrophobic force drives the molecules′ assembly into vesicles in THF/water. The π–π interaction of the pyrene groups subsequently occurred within the vesicular membrane. The assembly, however, is driven by the π–π interaction in DMSO/water (water content: 40–80 vol %) into membranes, which is attributed to the relatively higher degree of de-solvation (δ) of pyrene in DMSO. Further increase in δ (DMSO/90 vol % water) suppresses the π–π interaction and spherical particles are formed. On the other hand, the supersaturated solutions were prepared via a cycle of heating and cooling of Fp-pyrene in methanol or ethanol. Fp-pyrene aggregates into particles without the π–π interaction in the solutions with a lower degree of supersaturation (σ). In contrast, a higher σ induces the π–π interaction, which drives the assembly into nanotapes. The π–π interaction is a conditional effect depending on the solution conditions, which can be adjusted for the synthesis of nanostructures assembled from the same aromatic molecule. Getting stacked: The driving forces for self-assembly of a pyrene molecule are adjustable depending on the solution conditions.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201702281