@article {169, title = {Mechanochromic luminescence in copper nanoclusters: resolving structural transitions through microcrystal electron diffraction}, journal = {Chemical Communications}, year = {2025}, month = {06/2025}, type = {Communication}, abstract = {

MicroED reveals insights into mechanochromic luminescence in copper nanoclusters, demonstrating structural transitions from crystalline to amorphous state upon grinding, with restoration of crystallinity following solvent exposure. Luminescence switching occurs due to reversible amorphization-recrystallization rather than chemical changes, providing critical design principles for such stimuli-responsive materials.

}, keywords = {Carboranethiol, Cluster, crystals, Cu4, ED, electron diffraction, luminescence}, doi = {https://doi.org/10.1039/D5CC02594J}, url = {https://pubs.rsc.org/en/content/articlelanding/2025/cc/d5cc02594j}, author = {Harshita Nagar and Subrata Duary and Vivek Yadav and Amoghavarsha Ramachandra Kini and Sudhadevi Antharjanam and Tomas Base and Anirban Som and Brent L. Nannenga and Thalappil Pradeep} } @article {170, title = {A Silver-Chalcogenide Nanomaterial Enveloped with a Carborane-Thiolate Shell for the Electroreduction of CO2 to CO}, journal = {ACS Applied Nano Materials}, year = {2025}, month = {07/2025}, type = {Full article}, abstract = {

Electrocatalytic CO2 reduction using atomically precise nanomaterials has garnered significant research interest, owing to their controllable molecular structures. Here, we have synthesized an electrocatalyst composed of single crystals having a one-dimensional assembly of silver atoms bridged by sulfur atoms of meta-carborane-9-thiolates. The molecular structure of the framework was further characterized through high-resolution ESI-MS, which exhibited silver- and carborane-thiolate-containing ions originating from the fragmentation of the framework. This thermally stable solid acted as an efficient catalyst for the electrocatalytic conversion of CO2 to CO with a Faradaic efficiency of 85 {\textpm} 3\%. In situ Raman studies provided experimental verification of binding of CO2 to the framework. First-principles density functional theory calculations confirmed the feasible adsorption of CO2 with the Ag chains, highlighting its favorable interaction with the catalyst. Furthermore, free energy calculations revealed the rate-determining step of the conversion process to be the formation of *COOH. This study presents an efficient electrocatalyst featuring a one-dimensional silver-chalcogenide framework.

}, keywords = {silver chalcogenide CO2 reduction carborane thiol}, doi = {https://doi.org/10.1021/acsanm.5c01918}, url = {https://pubs.acs.org/doi/10.1021/acsanm.5c01918}, author = {Arijit Jana and Zhengyuan Li and Amoghavarsha Ramachandra Kini and Vivek Yadav and Akhil S Nair and Astrid Campos Mata and Jingjie Wu and Jan Machacek and Tomas Base and Biswarup Pathak and Soumyabrata Roy and Thalappil Pradeep} } @article {167, title = {Site-specific substitution in atomically precise carboranethiol-protected nanoclusters and concomitant changes in electronic properties}, journal = {Nature Communications}, volume = {16}, year = {2025}, month = {01/2025}, type = {Full article}, chapter = {1197}, abstract = {

We report the synthesis of [Ag17(o1-CBT)12]3- abbreviated as Ag17, a stable 8e$^{-}$ anionic cluster with a unique Ag@Ag12@Ag4 core-shell structure, where o1-CBT is ortho-carborane-1-thiol. By substituting Ag atoms with Au and/or Cu at specific sites we created isostructural clusters [AuAg16(o1-CBT)12]3- (AuAg16), [Ag13Cu4(o1-CBT)12]3- (Ag13Cu4) and [AuAg12Cu4(o1-CBT)12]3- (AuAg12Cu4). These substitutions make systematic modulation of their structural and electronic properties. We show that Au preferentially occupies the core, while Cu localizes in the tetrahedral shell, influencing stability and structural diversity of the clusters. The band gap expands systematically (2.09\ eV for Ag17 to 2.28\ eV for AuAg12Cu4), altering optical absorption and emission. Ultrafast optical measurements reveal longer excited-state lifetimes for Cu-containing clusters, highlighting the effect of heteroatom incorporation. These results demonstrate a tunable platform for designing nanoclusters with tailored electronic properties, with implications for optoelectronics and catalysis.

}, keywords = {Alloy, boron, carborane, Cluster, Copper, gold, luminescence, Metal, silver, Structure, thiol}, doi = {https://doi.org/10.1038/s41467-025-56385-w}, url = {https://www.nature.com/articles/s41467-025-56385-w}, author = {Vivek Yadav and Arijit Jana and Swetashree Acharya and Sami Malola and Harshita Nagar and Ankit Sharma and Amoghavarsha Ramachandra Kini and Sudhadevi Antharjanam and Jan Machacek and Kumaran Nair Valsala Devi Adarsh and Tomas Base and Hannu H{\"a}kkinen and Thalappil Pradeep} } @article {165, title = {Multicolor photoluminescence of Cu14 clusters modulated using surface ligands}, journal = {Chemical Science}, year = {2024}, month = {07/2024}, type = {Full article}, abstract = {

Copper nanoclusters exhibit unique structural features and their molecular assembly results in diverse photoluminescence properties. In this study, we present ligand-dependent multicolor luminescence observed in a Cu14 cluster, primarily protected by ortho-carborane-9,12-dithiol (o-CBDT), featuring an octahedral Cu6 inner kernel enveloped by eight isolated copper atoms. The outer layer of the metal kernel consists of six bidentate o-CBDT ligands, in which carborane backbones are connected through μ3-sulphide linkages. The initially prepared Cu14 cluster, solely protected by six o-CBDT ligands, did not crystallize in its native form. However, in the presence of N,N-dimethylformamide (DMF), the cluster crystallized along with six DMF molecules. Single-crystal X-ray diffraction (SCXRD) revealed that the DMF molecules were directly coordinated to six of the eight capping Cu atoms, while oxygen atoms were bound to the two remaining Cu apices in antipodal positions. Efficient tailoring of the cluster surface with DMF shifted its luminescence from yellow to bright red. Luminescence decay profiles showed fluorescence emission for these clusters, originating from the singlet states. Additionally, we synthesized microcrystalline fibers with a one-dimensional assembly of DMF-appended Cu14 clusters and bidentate DPPE linkers. These fibers exhibited bright greenish-yellow phosphorescence emission, originating from the triplet state, indicating the drastic surface tailoring effect of secondary ligands. Theoretical calculations provided insights into the electronic energy levels and associated electronic transitions for these clusters. This work demonstrated dynamic tuning of the emissive excited states of copper nanoclusters through the efficient engineering of ligands.

}, keywords = {carborane, Carboranethiol, Cluster, Copper, Cu14, luminescence, single-crystal, thiol}, doi = {https://doi.org/10.1039/D4SC01566E}, url = {https://pubs.rsc.org/en/content/articlelanding/2024/sc/d4sc01566e?fbclid=IwY2xjawEbPEpleHRuA2FlbQIxMAABHSdHrudEy8SHjsokfQULtsUmfvHic2gEFr4U065NwJ6qN1LFmIkYwaAntQ_aem_eQUA0V-1Rl2jNgjrSiijPw}, author = {Arijit Jana and Subrata Duary and Amitabha Das and Amoghavarsha Ramachandra Kini and Swetashree Acharya and Jan Machacek and Biswarup Pathak and Tomas Base and T. Pradeep} }