Helical stacking tuned by alkoxy side chains in pi-conjugated triphenylbenzene discotic derivatives.
We report on the synthesis and self-assembly of a new series of discotic molecules containing triphenylbenzene as the core and alkoxy side chain with varying length. It was found that compounds 3 a-c, 4 b and 5 b could form stable gels in several apolar solvents. Transmission electron microscopy (TEM) images revealed that their morphologies were very different for the different alkoxy-substituted organogels. In toluene or hexane, 3 b and 3 c resulted in both left- and right-handed helical fibers, whereas 3 a resulted in straight rigid fibers; 4 b and 5 b resulted in most straight fibers with a few twisted fibers. The results from FT-IR and UV/Vis absorption spectroscopy indicated that the hydrogen bonding and pi-pi interactions were the main driving forces for the formation of the self-assembled gels. Further detailed analysis of their aggregation modes were conducted by UV-visible absorption spectra and X-ray diffraction (XRD) measurements. Based on these findings, the influence of these peripheral alkoxy substituents on the gel formation and the aggregation mode were discussed. The special enhanced fluorescent emissions, which resulted from aggregation, were also found in the gel phase.
Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, P.R. China.
Chunyan
C
Bao
Ran
R
Lu
Ming
M
Jin
Pengchong
P
Xue
Changhui
C
Tan
Tinghua
T
Xu
Guofa
G
Liu
Yingying
Y
Zhao
D000438:Alcohols / Q000737:chemistry*; D001555:Benzene Derivatives / Q000138:chemical synthesis / Q000737:chemistry*; D013730:Terphenyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*
C515346:1,3,5-tri(4-aminophenyl)benzene; D000438:Alcohols; D001555:Benzene Derivatives; D013730:Terphenyl Compounds; C059688:alkoxyl radical