Intraconfigurational Transition due to Surface-Induced Symmetry Breaking in Noncovalently Bonded Molecules

Abstract

The interaction of molecules with surfaces plays a crucial role in the electronic and chemical properties of supported molecules and needs a comprehensive description of interfacial effects. Here, we unveil the effect of the substrate on the electronic configuration of iron porphyrin molecules on Au(111) and graphene, and we provide a physical picture of the molecule-surface interaction. We show that the frontier orbitals derive from different electronic states depending on the substrate. The origin of this difference comes from molecule-substrate orbital selective coupling caused by reduced symmetry and interaction with the substrate. The weak interaction on graphene keeps

Black Phosphorus for Directed Molecular Assembly with Weak Electronic Coupling

“…The localization of the states can be further evidenced from dI/dV maps which are shown in Figure 4d. These electronic properties are very similar to those of FeTPP on graphene [28] (see supporting information Figure S4) where a HOMO−LUMO gap of 2.9 V was measured and the localization of the molecule electronic states was similar. A noticeable difference is found at positive bias where 3 sharp peaks could be clearly distinguished on graphene around the LUMO state, whereas a broad peak is observed here and only two contributions can be distinguished.…”

“…After several scanning with various setpoint parameters, we were able to recover a good tip state allowing to visualize the atomic lattice of the BP on the same area. This procedure is similar to the one that we have used in our previous works on graphene [37,28,4]. The image of the BP surface shows the phosphorus zigzag rows (Figure 1b).…”

“…There are two types of molecules characterized by a bright or dark center. The molecules with a bright center correspond to FeTPP with a chlorine bonded to the Fe atom forming a FeTPP-Cl molecule [27,28]. Those with a dark center correspond to FeTPP.…”

“…The calculated interaction energies are presented in Figure 2a. We compare this interaction energy with the case of FeTPP on graphene that we take as a reference for weakly coupled FeTPP [28]. The optimized equilibrum configuration on BP is presented in Figure 2b.…”

Magnetic Energy Landscape of Dimolybdenum Tetraacetate on a Bulk Insulator Surface

“…The work is based on the recent observations that regular MoMo assemblies hold firmly on calcite (10.4) at ambient conditions [48]. MoMo seems particularly interesting for the vertical alignment of the Mo-Mo axis, that favors the symmetry breaking between the two Mo on the surface (a favorable condition for the onset of magnetic states [93]) and the external C-CH 3 linkers that prevent the molecule dissociation, even when all four Mo-Mo bonds are broken.While standard GGA-PBE functionals predict a nonmagnetic (NM) state with quadruple Mo-Mo bond and excited magnetic states at significantly higher energies (growing with the number of broken bonds and ultimately with the magnetization M), Hubbard corrections stabilize magnetic configurations (FM or AFM) with Mo atoms near their high-spin configurations and atomic magnetizations near their Hund's saturation limit of four. More importantly, the corrections render many FM states metastable.…”