Self-assembly and liquid-crystalline properties of 5-fluoroalkylporphyrins.
We report three crystal structures of a synthetic 5-fluoroalkylporphyrin molecule that was programmed for self-assembly. All the X-ray structures of zincated and free-base porphyrins Zn2 b, Zn5 a, and 2 b revealed rigorous pi-pi stacking and extremely hydrophobic interactions. Other the other hand, the strong aggregation of 5-fluoroalkylporphyrins in solution was also found. Interestingly, the regular nanopore formation of the 5-fluoroalkylporphyrin was visualized by atomic force microscopy (AFM). Importantly, the 5-fluoroalkylporphyrins possess liquid-crystalline properties that were confirmed by using a combination of differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) techniques. By comparison, the self-assembly of non-fluorine-containing porphyrins with similar structure showed much lower aggregation ability, as investigated by NMR techniques. Additionally, no birefringent mesophase was observed for the non-fluorine-containing porphyrin.
Jin
Li-Mei
LM
Key laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 354 Fenglin Road, 200032, Shanghai, China.
Yin
Juan-Juan
JJ
Chen
Liang
L
Zhou
Jin-Ming
JM
Xiao
Ji-Chang
JC
Guo
Can-Cheng
CC
Chen
Qing-Yun
QY
D018360:Crystallography, X-Ray; D005461:Fluorine / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D011166:Porphyrins / Q000737:chemistry*
D011166:Porphyrins; D005461:Fluorine