Perylene and perylene diimide (PDIs) are widely used for organic optical electronic materials due to their outstanding thermal stability, visible light absorption and high molar absorption coefficients. To tailor perylene and PDI’s optical and electronic properties for specific applications, molecular contortion and bay-functionalization have been proved as effective methods.
In this thesis, these strategies will be applied to perylene and PDI to develop novel optical and electronic materials. In the first chapter, the molecular contortion strategy is applied to perylene to tune singlet and triplet energies and successfully turn on singlet fission in thin films of contorted perylene. Perylene does not undergo singlet fission in its planar form. The tuning of the energetics that control singlet fission through molecular contortion can be applied to a large repertoire of established molecular chromophores.
In the second chapter, novel bay-functionalization reactions of PDI, which are base-assisted direct amination and N-heteroarylation, are discussed. The reactions are able to achieve up to 70% yield for mono N-heteroarylation. UV-Vis and EPR spectroscopy suggest that these reactions are mediated through PDI radical anions that are thermally induced by strong bases. An intriguing small-molecule white-light-emitter is constructed from this reaction.
In the third chapter, contorting PDIs to form chiral helicenes for Chiral Induced Spin Selectivity (CISS) is discussed. CISS allows for selective transportation of one electron spin and filtration out of the other spin, exhibiting great potential applications in spintronics, spin-polarized light-emission, and spin-controlled catalysis. However, the mechanism of CISS remains unclear and it is necessary to develop a molecular system that allows for the investigation of CISS effect at the atomic level. PDI-based helicenes could be an ideal model system for the investigation of CISS effect due to their chiroptical properties. The chirality of PDI-based helicene dimers is resolved without chiral HPLC separation by converting helicene enantiomers into diastereomers, where Prep TLC is used to separate the helicene diastereomers at a relatively large scale.
| Identifer | oai:union.ndltd.org:columbia.edu/oai:academiccommons.columbia.edu:10.7916/923y-pa66 |
| Date | January 2024 |
| Creators | Sun, Shantao |
| Source Sets | Columbia University |
| Language | English |
| Detected Language | English |
| Type | Theses |
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