Porphyrin Chemistry and Its Applications

Porphyrins are cyclic tetrapyrroles distinguished by their conjugated macrocyclic frameworks and ability to coordinate metal centres. They occupy pivotal functions in nature as the core of haem, chlorophyll and vitamin B12, mediating oxygen transport, photosynthetic electron transfer and enzymatic catalysis. Synthetic porphyrins leverage this structural motif for applications in photodynamic therapy, molecular electronics, sensing and solar energy conversion. The introduction of peripheral substituents, internal metalation and macrocycle expansion or contraction yields porphyrinoids with tailored absorption spectra, redox potentials and binding sites. Conformational distortion and heteroatom incorporation further modulate electronic properties, enabling fine-tuning of catalytic selectivity and supramolecular assembly. Such structural diversity underpins the development of artificial photosynthetic platforms, reaction-based chemosensors and organocatalysts, bridging fundamental studies with scalable technologies for sustainable energy and environmental remediation.

Research from Nature Portfolio

Recent investigations have engineered doubly N-confused and ring-contracted expanded porphyrins complexed with palladium and nickel ions, revealing antiaromatic character and red-shifted weak absorptions that may inform the design of next-generation catalysts and optoelectronic materials. A complementary study introduced a twisted-planar-twisted expanded porphyrinoid dimer that undergoes a selective methanol-promoted rearrangement, producing a distinct colourimetric change and demonstrating a proof-of-concept for reaction-based sensors with high selectivity.

Porphyrin Chemistry and Its Applications publication trend

The graph below shows the total number of articles in porphyrin chemistry and its applications across all publications each year (not limited to Nature Index journals).

Technical terms

Macrocycle: A large cyclic molecule composed of multiple repeating units, forming a ring of pyrrole subunits in porphyrins.

Metalation: The incorporation of a metal ion into the central cavity of a macrocycle, altering its electronic and catalytic properties.

N-confused porphyrin: An isomeric porphyrin in which the position or identity of an inner pyrrole nitrogen is modified, affecting coordination geometry.

Antiaromaticity: A property of cyclic conjugated systems with 4n π electrons, leading to destabilised electronic structures and distinctive magnetic responses.

Soret band: A strong absorption feature around 400–450 nm in porphyrin spectra, arising from π–π* transitions within the macrocycle.

Normal-coordinate structural decomposition (NSD): A method to quantify macrocycle distortions by decomposing crystallographic data into symmetry-adapted deformation modes.

References

1. Organometallic chemistry confined within a porphyrin-like framework. Chemical Society Reviews (2023).
2. Doubly N-confused and ring-contracted [24]hexaphyrin Pd-complexes as stable antiaromatic N-confused expanded porphyrins. Nature Communications (2023).
3. Twisted-Planar-Twisted expanded porphyrinoid dimer as a rudimentary reaction-based methanol indicator. Nature Communications (2020).
4. The shape of porphyrins. Coordination Chemistry Reviews (2021).
5. Complexes of N‐Confused Porphyrin Derivatives as Ortho‐Metallating Ligands. Synthesis, Structure, Redox Properties, and Chirality. Advanced Science (2023).