Highly Selective On‐Surface Synthesis of sp ² /sp‐Hybridized Heterochiral Triangular Nanorings

-hybridized heterochiral triangular nanorings. Subsequent annealing induces an elimination reaction, converting these rings into their sp-hybridized analogues while preserving chirality. In contrast, room-temperature deposition and postannealing predominantly produces linear chains. The structural evolution and selective reaction mechanisms are unequivocally characterized by scanning tunneling microscopy (STM), bond-resolution STM, synchrotron radiation photoemission spectroscopy (SRPES), and density functional theory (DFT) calculations. This work establishes a novel strategy for the precise synthesis of chiral triangular nanorings, revealing the critical role of surface-mediated conformational control and dynamic covalent bonding in determining product topology and chirality.