Electrochemical and Spectroscopic Studies of Fullerene Derivatives

Fullerene derivatives have emerged as versatile platforms for exploring electron transfer, redox stability and light–matter interactions at the molecular level. The unique spherical π‐conjugated framework of C₆₀ and higher fullerenes can be functionalised through cycloadditions, radical additions or ionic substitutions to tune electronic properties and solubility. Electrochemical methods such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) reveal the sequence and energetics of reduction and oxidation events, while spectroscopic techniques—including ultraviolet–visible (UV–Vis) absorption, infrared (IR) and electron paramagnetic resonance (EPR) spectroscopy—provide fingerprints of charge localisation, spin distribution and structural changes. The interplay of electrochemistry and spectroscopy has shed light on charge carrier mobility in organic photovoltaics, the design of redox‐active sensors and the development of molecular electronics. Advances in spectroelectrochemical cells now allow real‐time monitoring of intermediate species and correlate potential‐dependent spectral shifts with mechanistic pathways. Collectively, these studies demonstrate how controlled derivatisation of the fullerene cage can modulate frontier orbital energies, stabilise radical anions or cations and enable new functional materials with tailored optical and electronic responses.

Research from Nature Portfolio

Recent studies have employed in situ spectroelectrochemistry to monitor the one‐electron reduction processes of bisadduct and trisadduct fullerenes under precisely controlled potentials. Visible‐near infrared spectral changes track the evolution of radical anion bands, revealing how substituent patterns influence charge delocalisation and recombination kinetics. Simultaneous EPR measurements confirm the formation of long‐lived spin‐polarised states, suggesting routes to stable radical materials for quantum information applications.

Another investigation has combined electrochemical impedance spectroscopy with time‐resolved UV–Vis absorption to characterise the interfacial electron transfer between functionalised fullerenes and transparent conductive substrates. The work demonstrates that tailored side chains improve film morphology and facilitate charge extraction in organic solar cells, achieving enhanced photocurrent stability under prolonged illumination.

Electrochemical and Spectroscopic Studies of Fullerene Derivatives publication trend

The graph below shows the total number of articles in electrochemical and spectroscopic studies of fullerene derivatives across all publications each year (not limited to Nature Index journals).

Technical terms

Cyclic voltammetry: Electrochemical technique in which the electrode potential is swept linearly to induce redox processes and record current–potential profiles.

Spectroelectrochemistry: Analytical method combining spectroscopy and electrochemistry to observe species formation and spectral changes under applied potential.

Radical anion: Negatively charged species bearing an unpaired electron, often observed during one‐electron reduction of fullerenes.

Charge delocalisation: Distribution of electronic charge over multiple atoms or conjugated systems, stabilising radical or ionic states.

Electron paramagnetic resonance (EPR): Spectroscopic technique sensitive to unpaired electrons, used to probe spin states and radical structures.

References

1. Separation and identification of indene–C70 bisadduct isomers. Beilstein Journal of Organic Chemistry (2016).
2. 1,3,7,10,14,17,21,28,31,42,52,55-Dodeca­kis(trifluoro­meth­yl)- 1,3,7,10,14,17,21,28,31,42,52,55-dodeca­hydro­(C60–Ih)[5,6]fullerene. Acta Crystallographica Section E: Crystallographic Communications (2007).