Synthesis of Fully Conjugated Porphyrin Nanobelts

ongoing

π-Conjugated macrocycles are promising materials for applications in organic electronics and they are being studied to gain fundamental understanding of aromaticity. Cyclic porphyrin oligomers exhibit unique properties, such as ultrafast energy delocalization and quantum interference, and they serve as valuable models for studying aromaticity on the nanoscale. This project aims to synthesize the first fully π-conjugated porphyrin nanobelts (PNs). These PNs are expected to have stronger electronic delocalization than the single-strand porphyrin nanorings previously studied in Anderson's group. Two complementary work packages are proposed. In WP1, the target β,meso,β-triply-linked PNs will be synthesized using a cleavable covalent template. In WP2, curved building blocks will enable the synthesis of target β,β-fused PNs. The target PNs will be purified by recycling gel-permeation chromatography (GPC) and structurally characterized using Nuclear Magnetic Resonance (NMR) spectroscopy, mass spectrometry and single-crystal X-ray crystallography. The electronic and magnetic properties of the PNs will be elucidated using techniques such as NMR spectroscopy, UV-vis absorption and fluorescence spectroscopy, as well as Electron Paramagnetic Resonance (EPR) spectroscopy, backed up with quantum-chemical electronic structure calculations. This research will explore the electronic structures and photophysical properties of the fully conjugated NPs, and determine whether global (anti)aromaticity occurs in their neutral, oxidized or reduced states. This work will generate new insights into molecular structure-property relationships by studying unprecedented molecular nanostructures.