Long-Range Single-Molecule Transport and Assembly at Liquid Nitrogen Temperatures

Abstract

The bottom-up construction of functional matter from individually positioned atoms and molecules requires deterministic control over capture, transport, and assembly on surfaces. Although atomic manipulation is well established, extending comparable control to molecules remains challenging due to their complex internal degrees of freedom and surface interactions. Here, we demonstrate controlled single-molecule transport and assembly at liquid nitrogen temperatures using a scanning tunneling microscope. We designed a molecule with an intrinsic electric dipole moment, enabling efficient noncontact manipulation via electrostatic coupling to the tip. This strategy allows stable long-range translation and the programmable formation of defined dimers and larger assemblies. Systematic mapping of the operational parameter space, supported by first-principles calculations, identifies an electrostatic driving mechanism governing motion. Our approach shifts molecular nanomachine research from demonstrations under extreme cryogenic conditions to positional control under experimentally more accessible temperatures, establishing a practical platform for programmable molecular-scale engineering.