Epitaxial growth of a methoxy-functionalized quaterphenylene on alkali halide surfaces

•Growth of a methoxy-functionalized para-phenylene on dielectric surfaces is investigated.•Low-energy electron diffraction and X-ray diffraction techniques are employed for structural characterization.•Epitaxial growth of upright molecules only is documented.•Polarized optical microscopy together with atomic force microscopy complements the findings.

The epitaxial growth of the methoxy functionalized para-quaterphenylene (MOP4) on the (001) faces of the alkali halides NaCl and KCl and on glass is investigated by a combination of low energy electron diffraction (LEED), polarized light microscopy (PLM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Both domains from upright molecules as well as fiber-like crystallites from lying molecules form. Neither a wetting layer from lying molecules nor widespread epitaxial fiber growth on the substrates is detected. Our results focus on the upright standing molecules, which condense into a thin film phase with an enlarged layer spacing compared to the bulk phase.