@article {47011, title = {Unprecedented isomerism-activity relation in molecular electrocatalysis}, journal = {Journal of Physical Chemistry Letters}, volume = {11}, year = {2020}, month = {JAN }, pages = {263-271}, type = {Article}, abstract = {

The role of electrocatalysts in energy storage/conversion, biomedical and environmental sectors, green chemistry, and much more has generated enormous interest in comprehending their structure-activity relations. While targeting the surface-to-volume ratio, exposing reactive crystal planes and interfacial modifications are time-tested considerations for activating metallic catalysts; it is primarily by substitution in molecular electrocatalysts. This account draws the distinction between a substituent{\textquoteright}s chemical identity and isomerism, when regioisomerism of the -NO2 substituent is conferred at the {\textquoteleft}{\textquoteleft}alpha{\textquoteright}{\textquoteright} and {\textquoteleft}{\textquoteleft}beta{\textquoteright}{\textquoteright} positions on the macrocycle of cobalt phthalocyanines. Spectroscopic analysis and theoretical calculations establish that the beta isomer accumulates catalytically active intermediates via a cumulative influence of inductive and resonance effects. However, the field effect in the alpha isomer restricts this activation due to a vanishing resonance effect. The demonstration of the distinct role of isomerism in substituted molecular electrocatalysts for reactions ranging from energy conversion to biosensing highlights that isomerism of the substituents makes an independent contribution to electrocatalysis over its chemical identity.

}, issn = {1948-7185}, doi = {10.1021/acs.jpclett.9b02689}, author = {Kottaichamy, Alagar Raja and Begum, Shabbah and Nazrulla, Mohammed Azeezulla and Dargily, Neethu Christudas and Devendrachari, Mruthyunjayachari Chattanahalli and Bhat, Zahid Manzoor and Thimmappa, Ravikumar and Kotresh, Harish Makri Nimbegondi and Vinod, Chathakudath Prabhakaran and Thotiyl, Musthafa Ottakam} } @article {48835, title = {Unprecedented energy storage in metal-organic complexes via constitutional isomerism}, journal = {Chemical Science}, volume = {14}, year = {2023}, month = {JUN}, pages = {6383-6392}, type = {Article}, abstract = {

The essence of any electrochemical system is engraved in its electrical double layer (EDL), and we report its unprecedented reorganization by the structural isomerism of molecules, with a direct consequence on their energy storage capability. Electrochemical and spectroscopic analyses in combination with computational and modelling studies demonstrate that an attractive field-effect due to the molecule{\textquoteright}s structural-isomerism, in contrast to a repulsive field-effect, spatially screens the ion-ion coulombic repulsions in the EDL and reconfigures the local density of anions. In a laboratory-level prototype supercapacitor, those with beta-structural isomerism exhibit nearly 6-times elevated energy storage compared to the state-of-the-art electrodes, by delivering similar to 535 F g(-1) at 1 A g(-1) while maintaining high performance metrics even at a rate as high as 50 A g(-1). The elucidation of the decisive role of structural isomerism in reconfiguring the electrified interface represents a major step forward in understanding the electrodics of molecular platforms.

}, issn = {2041-6520}, doi = {10.1039/d3sc01692g}, author = {Kottaichamy, Alagar Raja and Deebansok, Siraprapha and Deng, Jie and Nazrulla, Mohammed Azeezulla and Zhu, Yachao and Bhat, Zahid Manzoor and Devendrachari, Mruthyunjayachari Chattanahalli and Vinod, Chathakudath Prabhakaran and Kotresh, Harish Makri Nimbegondi and Fontaine, Olivier and Thotiyl, Musthafa Ottakam} } @article {49136, title = {Unusual ligand assistance in molecular electrocatalysis via interfacial proton charge assembly}, journal = {Journal of Physical Chemistry Letters }, volume = {14}, year = {2023}, month = {JUN }, pages = {5377-5385}, type = {Article}, abstract = {

We show that the ability of the ligand to reorganizethe electricdouble layer (EDL) often dominates the electrocatalysis contrary totheir inductive effect in the spectrochemical series, leading to counterintuitiveelectrocatalysis. With water oxidation and chlorine evolution as theprobe reactions, the same catalytic entity with carboxy functionalizedligand exhibited surprisingly higher electrochemical activity in comparisonto the aggressively electron-withdrawing nitro functionalized ligands,which is contrary to their actual location in the spectrochemicalseries. Spectroscopic and electrochemical analyses suggest the enrichmentof catalytically active species in the carboxy substituted ligandvia proton charge assembly in the EDL that in turn enhances the kineticsof the overall electrochemical process. This demonstration of lessobvious ligands becoming indispensable in electrocatalysis suggestsa blind designing of ligands solely based on their inductive effectshould be reconsidered as it will prevent the utilization of the maximumpotential of the molecule in electrocatalysis.

}, issn = {1948-7185}, doi = {10.1021/acs.jpclett.3c01262}, author = {Mukhopadhyay, Sanchayita and Kottaichamy, Alagar Raja and Chame, Pallavi Vyankuram and Ghosh, Prasenjit and Vinod, Chathakudath Prabhakaran and Makri Nimbegondi Kotresh, Harish and Kanade, Sandeep C. and Thotiyl, Musthafa Ottakam} }