Identifying Subphthalocyanine Molecule Isomers by Using a Scanning Tunneling Microscope

Abstract

Structural isomers of chloro[tri-tert-butyl-subphthalocyaninato]boron(III) (TBSubPc) molecules on the Au(111) surface were identified by using the scanning tunneling microscope (STM). A TBSubPc is a corn-shaped and triangular molecule with a chloride atom at the top and three tert-butyl groups on its periphery. The molecule has four kinds of structural isomers depending on the binding sites of the tert-butyl groups. It can have two different adsorbed configurations on the surface, Cl-up and Cl-down. The STM image shows three spots that correspond to the three tert-butyl groups and one central spot that reflects the Cl atom. Analyzing the relative distances between the spots enables us to identify the isomers and the adsorbed configurations.

Phthalocyanines: old dyes, new materials. Putting color in nanotechnology

“…Vacuum deposition of subphthalocyanines onto silicon(111), 43 silver, 93-95 copper 96 and gold 97,98 substrates have been performed to yield highly ordered arrays that were studied by STM. The single molecules usually appear as doughnut-shaped spots (due to the fast rotation around the symmetry axis), arranged in hexagonal honeycomb patterns (Fig.…”

“…14). [93][94][95][96][97][98] Co-deposition of chloro-subphthalocyanine and C 60 -fullerene on a silver surface led to the formation of stable and well-ordered intermixed monolayers (Fig. 15).…”

Molecular Suction Pads: Self‐Assembled Monolayers of Subphthalocyaninatoboron Complexes on Gold

“…The lack of signals for B and Cl can be attributed to the small elemental concentration of both elements (~1 atomic %) and the large surface area per molecule leading to a small surface density of BCl moieties in a monolayer. A loss of the axial Cl ligand upon adsorption on gold is highly unlikely, since such a process has never been observed for Cl [8a,8b,8d,11] or other, more extended ligands. [4,9,12] Thirdly, the SAM contains small amounts of oxygen.…”

“…[13] These effective thickness values are smaller than the lengths of linear n -octyl and n -dodecyl chains (12.0 Å and 17.0 Å, respectively). [11] However, these smaller values are a result of both the low density of the alkyl chains, compared to monodentate n -alkane thiol SAMs and the fact that the alkyl chains do not point orthogonally away from the surface. Instead they adopt a tilted orientation – almost parallel to the surface.…”

Self-Assembled Monolayers of Subphthalocyanines on Gold Substrates

“…The organization of these aromatic macrocycles on metal substrates, in the form of nanoclusters or flat monolayers, has great potential for the development of different organic materials. Thin films of SubPcs have been built using several techniques, namely, spin-coating, vacuum deposition onto metal substrates, or Langmuir−Blodgett techniques . However, none of these techniques permit an actual chemical attachment of the molecules onto the surface and hence do not usually provide fine control over their arrangement and conformation, which is especially interesting in the case of these cone-shaped macrocycles.…”