Electronic Structure and Bistable Conformational Study of the Tetraphenylporphyrin Erbium(III) Acetylacetonate Complex on the CaF2/Si(100) Surface at Low Temperatures

The synthesis of tetraphenylporphyrin erbium(III) acetylacetonate (acac) complexes is realized and their properties studied at the nanoscale when adsorbed on a semi-insulating CaF2/Si(100) surface. Our findings reveal that ErTPP-(acac) molecules can adsorb in two main on-site conformations. Following precisely located dI/dV measurements various specific positions [phenyls, pyrroles, Er-(acac)], relative locations Er cation apical ligand be deciphered for each observed conformation. Hence, one adsorbate conformations presents acac parallel to porphyrin plane with atom outside macrocycle plane. second conformation related what known gas phase, where oriented vertically top atom. This work combined theoretical investigation uses density functional theory methods bring into light details Additional proofs our discoveries are vibrational excitations ErTPP-(acac). A comparison estimation modes reveals how electronic resonance near valence-band edge insulting layer suitable distinguish between