Photoconversion of Ag₃₁ to Ag₄₂ Initiated by Solvated Electrons

Light-matter interactions, especially in atomically precise nanomaterials, belong to an unexplored realm of research with potential benefits for the synthesis of materials. Here, we present an interesting light-activated expansion process of an Ag 31 nanocluster to an Ag 42 analogue, both clusters being protected with 6-(dibutylamino)-1,3,5-triazine-2, 4-dithiol (shortly, TRZ-H 2 ) ligands. The conversion process was initially monitored through UV–vis, revealing that the violet-colored Ag 31 got converted to greenish Ag 42, exhibiting their characteristic absorption features. High-resolution mass spectrometric studies confirmed that the as-synthesized [Ag 31 (TRZ) 10 ] with coexisting di- and monoanionic charged species in dichloromethane solution got converted to [Ag 42 (TRZ) 13 ] with a dipositive charge state. Electrochemical studies revealed the photoresponsive nature of Ag 31, and light illumination resulted in transient intermediate clusters covered with solvated electrons, which contributed to the core expansion. Ag 31 is NIR-emitting, while Ag 42 is red-emitting. The ultrafast transient absorption studies reveal that Ag 42 has strikingly short excited-state carrier dynamics than Ag 31 . The stable excited-state carriers for Ag 31 upon photoexcitation also underline the unique electronic characteristics responsible for such light-activated structural evolution.