The miniaturization limits of electronic and mechanical devices depend on the minimum pattern periodicity that is stable in ambient conditions. Here we demonstrate an atomic force microscopy lithography that enables the patterning of 2 nm organic structures with 6 nm periodicities in air. The method is based on the formation of a nanoscale octane meniscus between a sharp conductive protrusion and a silicon (100) surface (1,2). The application of a high electrical field (~10V/nm) produces the polymerisation and cross-linking of the octane molecules within the meniscus followed by their deposition (3). The resulting pattern periodicities are very close to the ultimate theoretical limits achievable in air (~3 nm). The chemical composition of the patterns has been characterized by photoemission spectroscopy. We also demonstrate that the lithography can be up-scaled for parallel patterning (4).