Title
J-aggregation in porphyrin nanoparticles induced by diphenylalanine
Author
Fengqing Li, Dongzhi Liu, Tianyang Wang, Jianxin Hu, Fancui Meng, Haiya Sun, Zhi Shang, Pingan Li, Wenhui Feng, Wei Li, Xueqin Zhou
Year
2017
Journal
Journal of Solid State Chemistry
Abstract
In this report, L-diphenylalanine-decorated tetraphenylporphyrin (TPPtFFC) was synthesized and self-assembled into regular nano-architechtures. The morphology of the assemblies varied with the concentration of TPPtFFC. The absorption spectra of the nanoparticles show the Soret band merges with the Q bands and redistributes with great red-shift, indicative of the formation of J-aggregates of the porphyrin molecules. The fluorescence emission of the nanoparticles is merged and red-shifted to near-infrared region. Studies of absorption and fluorescence spectra reveal an indispensible role of diphenylalanine group in the formation of J-aggregates. The Raman spectra disclose that diprotonation of the porphyrin core contributes to delocalized coherent excited states in the nanoparticles. The positive cotton effect in circular dichroism spectra corresponding to the Soret band of TPPtFFC in solution confirms the formation of J-aggregates with right-handed chirality of the dipole moment. This report will shed light on the rational design of porphyrin-peptide conjugates to mimic naturally light-harvesting complexes.
Instrument
J-810
Keywords
Circular dichroism, Nanostructures, Materials