Interplay of hydrogen bonding and molecule–substrate interaction in self-assembled adlayer structures of a hydroxyphenyl-substituted porphyrin

Abstract

The formation of hydrogen-bonded organic nano-structures and the role of the substrate lattice thereby were investigated by scanning tunneling microscopy. The self-organization of 5,10,15,20-tetra(p-hydroxyphenyl)porphyrin (H 2 THPP) molecules leads to two molecular arrangements on Au(111). One of these is characterized by pair-wise hydrogen bonding between hydroxyl groups and a low packing density which enables a rotation of individual molecules in the structure. A different interaction with stronger chain-like hydrogen bonding and additional interactions of phenyl groups was observed for the second structure. The influence of the substrate on the epitaxial behavior is demonstrated by the adsorption of H 2 THPP on the highly anisotropic Ag(110) substrate. There, several balances between the occupation of favorable adsorption positions and the number of hydrogen bonds per molecule were found. The molecules form molecular chains on Ag(110) and also assemble into two-dimensional periodic arrangements of differently sized close-packed blocks similar to the second type of supramolecular ordering found on Au(111). Dispersion corrected Density Functional Theory calculations were applied to understand the adsorption and complex epitaxy of these molecules. It is shown that the azimuthal orientation of the saddle-shape deformed molecule plays an important role not only for the intermolecular but also for the molecule-substrate interaction.

Two-Dimensional Self-Assembly Monitored by Hydrogen Bonds for Triphenylene-Based Molecules: New Role for Azobenzenes

“…[21][22][23] These chiral assemblies can be stabilized by hydrogen bonding, but the origin of chirality mostly comes from the initial chirality of the molecules themselves. It is in particular the case of polyaromatic and heterocyclic compounds, 24,25 but also of the so-called bio-molecules like amino acids 26 or nucleic acid building blocks 27 which drive the research in the promising areas of biosensors and biomaterials.…”

Structural study of monolayer cobalt phthalocyanine adsorbed on graphite

“…The interplay of single molecules on a substrate and their self-assembly properties were already investigated for various kinds of molecules and substrate materials [4][5][6][7][8][9][10][11][12][13] . Their small size makes them very suitable candidates to serve as building blocks of functional nanostructures.…”

Synthesis, spectroscopic characterization and thermogravimetric analysis of two series of substituted (metallo)tetraphenylporphyrins

“…5 together with the one of H 2 TPP(OH) 4 . In our earlier studies [6–7], H 2 TPP(OH) 4 could be deposited successfully by applying OMBD parameters analogous the those described above. A comparison especially of the onset temperatures of the decomposition processes reveals that H 2 TPP(OH) 4 is obviously significantly more thermally stable than the here reported (metallo)porphyrins.…”

“…Among such molecules metalloporphyrins are very promising in terms of diverse applications [4]. Recently, we reported on the deposition of thin films of porphyrins of the type H 2 TPP(OH) 4 (tetra( p -hydroxyphenyl)porphyrin) [6–7] and MTPP(OMe) 4 /H 2 TPP(OMe) 4 (tetra( p -methoxyphenyl)porphyrin) (M = Cu [8–9], Ni [9]), cf. Fig.…”

“…The aim of this report is not only to describe their synthesis and characterization (ESIMS, FTIR, NMR, UV–vis) but also to study to which extend these new (metallo)porphyrins are suitable to be deposited in form of thin films by OMBD. Therefore, the thermal stabilities derived from TG studies of selected representatives of 2/2a – d and 3/3a – d in comparison with that of H 2 TPP(OH) 4 [6–7] will be discussed together with the results of OMBD studies.…”