Transuranic Hybrid Materials: Crystallographic and Computational Metrics of Supramolecular Assembly

Autor(es)

Surbella, III, Robert G. ; Ducati, Lucas C. ; Pellegrini, Kristi L. ; McNamara, Bruce K. ; Autschbach, Jochen ; Schwantes, Jon M. ; Cahill, Christopher L.

• Tipo de documento: Artigo Científico
• Fonte: Journal of the American Chemical Society; v. 139, n. 31, p. 10843-10855, AUG 9 2017.
• Citações Web of Science: 17

Resumo

Assembly of a family of 12 supramolecular compounds containing {[}AnO(2)Cl(4)](2-) (An = U, Np, Pu), via hydrogen and halogen bonds donated by substituted 4-X-pyridinium cations (X = H, Cl, Br, I), is reported. These materials were prepared from a room-temperature synthesis wherein crystallization of unhydrolyzed and valence-pure {[}An(VI)O2Cl4](2-) (An = U, Np, Pu) tectons is the norm. We present a hierarchy of assembly criteria based on crystallographic observations and subsequently quantify the strengths of the non-covalent interactions using Kohn-Sham density functional calculations. We provide, for the first time, a detailed description of the electrostatic potentials of the actinyl tetrahalide dianions and reconcile crystallographically observed structural motifs and non-covalent interaction acceptor-donor pairings. Our findings indicate that the average electrostatic potential across the halogen ligands (the acceptors) changes by only similar to 2 kJ mol(-1) across the AnO(2)(2+) series, indicating that the magnitude of the potential is independent of the metal center. The role of the cation is therefore critical in directing structural motifs and dictating the resulting hydrogen and halogen bond strengths, the former being stronger due to the positive charge, centralized on the pyridyl nitrogen, N-H+. Subsequent analyses using the quantum theory of atoms in molecules and natural bond orbital approaches support this conclusion and highlight the structure directing role of the cations. Whereas one can infer that Columbic attraction is the driver for assembly, the contribution of the non-covalent interaction is to direct the molecular-level arrangement (or disposition) of the tectons. (AU)

• Processo FAPESP: 14/21930-9 - Estudo do efeito do solvente na constante de acoplamento 1JPt-Tl em complexos de metais pesados por dinâmica molecular ab initio
• Beneficiário: Lucas Colucci Ducati
• Modalidade de apoio: Bolsas no Exterior - Pesquisa