Scanning tunneling microscopy investigation of vanadyl and cobalt(II) octaethylporphyrin self-assembled monolayer arrays on graphite

Two-dimensional crystals of [2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine] vanadium(IV) oxide and cobalt(II) (VOOEP and CoOEP, respectively) at the interface of 1-tetradecene and highly oriented pyretic graphite (HOPG) were studied by scanning tunneling microscopy (STM). The lattice parameters were determined for VOOEP (a = 1.61 ± 0.1 nm, b = 1.46 ± 0.05 nm, Γ = 61 ± 3°) and CoOEP (a = 1.48 ± 0.08 nm, b = 1.42 ± 0.07 nm, Γ = 62.0 ± 4°), which were calibrated using the HOPG lattice as a reference. The center metal dependence observed by high-resolution STM analysis of octaethylporphyrin and the differences between VOOEP and CoOEP are proved.