Electron-Withdrawing meso-Substituents Turn On Magneto-Optical Activity in Porphyrins
Emigdio E Turner1, Trong-Nhan Pham2, Samuel Peter Smith1
1Department of Chemistry and Chemical Biology, Laboratory for Magneto-Optic Spectroscopy, University of New Mexico, Albuquerque, New Mexico 87131, United States.
Inorganic Chemistry
|February 15, 2024
Summary
Synthesized metalloporphyrins with pentafluorophenyl groups show enhanced magneto-optical activity (MOA). This finding aids in designing advanced magneto-optical materials for devices and quantum computing applications.
Area of Science:
- Materials Science
- Physical Chemistry
- Spectroscopy
Background:
- Metalloporphyrins are essential components in developing advanced functional materials.
- Magneto-optical activity (MOA) is critical for next-generation magneto-optical devices and quantum computing.
- Tuning molecular structure offers a pathway to tailor MOA properties.
Purpose of the Study:
- To synthesize and characterize metalloporphyrins with varying meso-substituents.
- To investigate the impact of pentafluorophenyl groups on magneto-optical activity.
- To provide insights for the rational design of novel magneto-optical materials.
Main Methods:
- Synthesis of square planar metalloporphyrins, including 5,10,15,20-tetraphenylporphyrin (TPP) and 5,10,15,20-tetrapentafluorophenylporphyrin (TPFPP) derivatives.
- Characterization of magneto-optical activity (MOA) using magnetic circular dichroism (MCD) and magneto-optical rotary dispersion (MORD) spectroscopy.
- Theoretical analysis using the Gouterman four-orbital model to explain observed MOA differences.
Main Results:
- Metalloporphyrins with meso-pentafluorophenyl substituents exhibited significantly enhanced MOA compared to those with phenyl groups.
- The study systematically compared MOA across different metal ions (Zn2+, Ni2+, Pd2+, Pt2+) within TPP and TPFPP frameworks.
- Distinct differences in MOA were observed and correlated with the electronic and structural properties influenced by the meso-substituents.
Conclusions:
- The presence of meso-pentafluorophenyl groups is a key factor in enhancing the magneto-optical activity of metalloporphyrins.
- The Gouterman four-orbital model effectively explains the observed structure-property relationships in MOA.
- These findings facilitate the rational design and development of tailored metalloporphyrin-based magneto-optical materials.
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