biostudies-literatureUnknown15(11)Hassan NThe everlasting pursuit of hybrid organic-inorganic lead-free semiconductors has directed the focus towards eco-friendly copper-based systems, perhaps because of the diversity in chemistry, controlling the structure-property relationship. In this work, we report single crystals of a Cu(i) halide-based perovskite-like organic-inorganic hybrid, (TMA)Cu<sub>2</sub>Br<sub>3</sub>, (TMA = tetramethylammonium), consisting of unusual one-dimensional inorganic anionic chains of -(Cu<sub>2</sub>Br<sub>3</sub>)-, electrostatically stabilized by organic cations, and the Cu(i)-Cu(i) distance of 2.775 Å indicates the possibility of cuprophilic interactions. X-ray photoelectron spectroscopy measurements further confirmed the presence of exclusive Cu(i) in (TMA)Cu<sub>2</sub>Br<sub>3</sub> and electronic structure calculations based on density functional theory suggested a direct bandgap value of 2.50 eV. The crystal device demonstrated an impressive bulk photovoltaic effect due to the emergence of excitonic Cu(i)-Cu(i) interactions, as was clearly visualized in the charge-density plot as well as in the Raman spectroscopic analysis. The single crystals of a silver analogue, (TMA)Ag<sub>2</sub>Br<sub>3</sub>, have also been synthesized revealing a Ag(i)-Ag(i) distance of 3.048 Å (signature of an argentophilic interaction). Unlike (TMA)Cu<sub>2</sub>Br<sub>3</sub>, where more density of states from Cu compared to Br near the Fermi level was observed, (TMA)Ag<sub>2</sub>Br<sub>3</sub> exhibited the opposite trend, possibly due to variation in the ionic potential influencing the overall bonding scenario.Chemical science4075-4085https://www.ebi.ac.uk/biostudies/studies/S-EPMC10935718biostudies-literatureExcitonic cuprophilic interactions in one-dimensional hybrid organic-inorganic crystals.PMC10935718Nagaraja SSaha SHassan NBallav NTarafder KfalseExcitonic cuprophilic interactions in one-dimensional hybrid organic-inorganic crystals.The everlasting pursuit of hybrid organic-inorganic lead-free semiconductors has directed the focus towards eco-friendly copper-based systems, perhaps because of the diversity in chemistry, controlling the structure-property relationship. In this work, we report single crystals of a Cu(i) halide-based perovskite-like organic-inorganic hybrid, (TMA)Cu<sub>2</sub>Br<sub>3</sub>, (TMA = tetramethylammonium), consisting of unusual one-dimensional inorganic anionic chains of -(Cu<sub>2</sub>Br<sub>3</sub>)-, electrostatically stabilized by organic cations, and the Cu(i)-Cu(i) distance of 2.775 Å indicates the possibility of cuprophilic interactions. X-ray photoelectron spectroscopy measurements further confirmed the presence of exclusive Cu(i) in (TMA)Cu<sub>2</sub>Br<sub>3</sub> and electronic structure calculations based on density functional theory suggested a direct bandgap value of 2.50 eV. The crystal device demonstrated an impressive bulk photovoltaic effect due to the emergence of excitonic Cu(i)-Cu(i) interactions, as was clearly visualized in the charge-density plot as well as in the Raman spectroscopic analysis. The single crystals of a silver analogue, (TMA)Ag<sub>2</sub>Br<sub>3</sub>, have also been synthesized revealing a Ag(i)-Ag(i) distance of 3.048 Å (signature of an argentophilic interaction). Unlike (TMA)Cu<sub>2</sub>Br<sub>3</sub>, where more density of states from Cu compared to Br near the Fermi level was observed, (TMA)Ag<sub>2</sub>Br<sub>3</sub> exhibited the opposite trend, possibly due to variation in the ionic potential influencing the overall bonding scenario.2024-01-01T00:00:00Z2024 Mar2025-04-21T19:06:27.054Z2025-04-05T17:29:36.547ZS-EPMC109357183848722910.1039/d3sc06255d