Colloquium: Electroreduction of Diazoniums: School Chemistry Concept to Molecular Electronics and Beyond

ABSTRACT

Molecules act as nanogaps between the two electrical contacts followed by current-voltage (I-V) analysis, which is often termed “molecular electronics”.[1] The foundation stone of molecular electronics lies in understanding the charge transport mechanisms for which many of the concepts developed from electrochemistry.[2] Electrochemistry plays a pivotal role in scrutinizing electrode-electrolyte interface phenomena, and electrochemical properties of molecular species. Inherent endowments possessed by molecules such as small size, solution-processibility, tuneable electronics, and suitable anchoring groups offer great advantages in conjunction with fascinating electronic functionalities. Interface stability and control of molecular film thickness at the nanoscale are paramount for semiconductor devices easily achievable by electrochemically driven reduction of aryl diazonium salts.

In this talk, I will discuss how the electrochemical grafting method can be employed in growing controllable molecular nano-architectures on technologically relevant ITO electrodes for large-scale molecular junctions. Molecular junctions composed of small organic molecules, metal complexes, and molecule-nanoparticle heterostructures sandwiched between two electrodes will be highlighted. The importance and diverse applications of electrochemical grafted molecular layers in charge transport, memory, charge storage, and spintronic applications will be discussed.[3-8]

References

[1]        R. Gupta, J. A. Fereiro*, A. Bayat, A. Pritam, M. Zharnikov*, P. C. Mondal*, Nat. Rev. Chem. 2023, 7, 106–122.
[2]        R. Gupta, P. Jash, P. Sachan, A. Bayat, V. Singh, P. C. Mondal*, Angew. Chem., Int. Ed. 2021, 60, 26904–26921.
[3]        R. Gupta, S. Bhandari, S. Kaya, K. P. Katin, P. C. Mondal*, Nano Lett. 2023, 23, 10998–11005.
[4]        N. Singh, A. Malik, P. Sethi, P. C. Mondal*, Small 2024, 2403108, 1–11.
[5]        R. Gupta, A. Malik, K. Kumari, S. K. Singh, V. Vivier*, P. C. Mondal*, Chem. Sci. 2024, 15, 8775–8785.
[6]        R. Gupta, J. Pradhan, A. Haldar, C. Murapaka, P. C. Mondal*, Angew. Chem., Int. Ed. 2023, 62, e2023074.
[7]        R. Kaur, A. Malik, R. Guptaa, K. Kumari, S. K. Singh, P. R. Bueno, P. C. Mondal*, Chem. Sci. 2025, Advance Article.
[8]        N. Singh, A. Pritam, J. Fransson, P. C. Mondal*, Adv. Funct. Mater., 2025, 2413761.

BIOGRAPHY

Prof. Prakash Chandra Mondal is currently an Associate Professor at the Department of Chemistry, IIT Kanpur. He obtained his M.Sc. at IIT Kharagpur and Ph.D. at the University of Delhi. He was a post-doctoral fellow at the Weizmann Institute of Science, Israel (2013-2016), then moved to the University of Alberta, Canada. Before joining IIT Kanpur in 2019, he was a Marie-Curie post-doctoral Fellow at the University of Valencia, Spain.

The research team led by Prof. Mondal has been devoted to surface chemistry, molecular electronics, and molecular electrochromic devices. Prof. Mondal is the author of many international journals of repute, including Nature Reviews Chemistry, JACS, ACS NANO, Adv. Mater., Nano Lett., Adv. Funct. Mater., Acc. Chem. Res., Angew. Chem., to mention a few. Since 2021, he has been serving as an Editorial Board Member of a journal, Analyst (RSC). He received the Young Faculty Research Award, the BRICS Young Scientist Award, and the Thieme Chemistry Journals Award 2025.