Probing metal-molecule contact at the atomic scale via conductance jumps

Understanding the formation of metal-molecule contact at microscopic level is key towards controlling and manipulating atomic-scale devices. Employing two isomers bipyridine, $4,{4}^{\ensuremath{'}}$ bipyridine $2,{2}^{\ensuremath{'}}$ between gold electrodes, here, we investigate a bond by studying charge transport through single molecular junctions using mechanically controlled break junction technique room temperature. While both molecules form during breaking process, closing traces show unambiguously for via conductance jump from tunneling regime, referred to as ``jump contact,'' being absent bipyridine. Through statistical analysis data, along with dynamics first-principles calculations, establish that strongly connected structure electrodes well how broken providing important insights molecule in an electronic device.