“…[ 5 , 9 ] From the theoretical view, the subtle interplay of the partner molecules has significant influence on proton tunneling. [ 10 , 11 , 12 , 13 ] Previous experimental studies have shown that the surrounding environment can modify the proton transfer rate,[ 14 , 15 , 16 , 17 , 18 , 19 ] however, little experimental data is available on how the proton tunneling process is affected by the environment at the few‐molecules level. Herein, we report the direct observation and precise measurement of proton transfer of the formic acid dimer lying on the surface of an aromatic π system.…”