Complexation of Sc3N@C80 as a model rare-earth nitride cluster fullerene with different crystallizing agents: A DFT analysis

We report on a computational study (at the PBE-D2/DNP level of DFT) of the bonding strength, geometry and selected electronic properties of the noncovalent dyads between different crystallizing agents (CAs) and the scandium nitride cluster (Sc3N) encapsulated by Ih-C80 endohedral fullerene (Sc3N@C80). The crystallizing agents studied were nickel(II) octaethylporphyrin (NiOEP), decapyrrylcorannulene (DPC), Zn tetraphenyl porphyrin (ZnTPP), and Ni tetramethyldibenzo-tetraazaannulenato (NiTMTAA). The strength of noncovalent interactions between the NCF and CAs decreases in the following order: Sc3N@C80 + NiOEP-in > Sc3N@C80 + DPC > Sc3N@C80 + NiOEP-out > Sc3N@C80 + ZnTPP > Sc3N@C80 + NiTMTAA-me > Sc3N@C80 + NiTMTAA-bz. The Sc⋯CC80 distances show negligible changes for the NCF in all the cases. The inner cluster Sc3N remains always planar despite of the use of different CAs. Two general patterns of HOMO-LUMO distribution were found. The dominating one, found in all the dyads except for the two formed with NiOEP, is when no HOMO fraction is detected on Sc3N@C80 component, but instead solely on the corresponding CA; on the contrary, the LUMO is concentrated on NCF.