RT info:eu-repo/semantics/article
T1 Design rules for Sb and bi porphyrin capsules: Para-substitution effects and pnictogen bond conformational control
A1 Cubero Pascual, Daniel
A1 García Romero, Álvaro
A1 Barbero San Juan, Héctor
A1 García Rodríguez, Raúl
K1 Conformation
K1 Encapsulation
K1 Ligands
K1 Pnictides
K1 Pyrroles
K1 2303 Química Inorgánica
AB Herein, we investigate the interplay between the heavy pnictogen bridgehead atom (E) in the tris(3-pyridyl) linkers E(3-py)3 (E = Sb (1), Bi (2)), and meso-aryl substituents on the metalloporphyrin scaffolds MTPPX (M = Zn, Mg; TPPX = substituted tetraphenylporphyrin) with respect to capsule formation and conformational control. Coordination of 1 and 2 to para-substituted zinc porphyrins ZnTPPOMe and ZnTPPBr yielded partially encapsulated semicapsules {[E(3-py)3]·(ZnTPPX)2}, while MgTPPBr produced oligomeric structures, showing that relatively bulky para-substituents disfavor complete 1:3 capsule formation. In contrast, coordination of 1 and 2 to perfluorinated ZnTPPF5 promotes the formation of full 1:3 capsules {[E(3-py)3]·(ZnTPPF5)3}, stabilized by three intramolecular E···F pnictogen bonds (PnBs) that give rise to a unique “blocked” conformation. DFT calculations indicate that distal porphyrin coordination enhances Lewis acidity at E, deepening its σ-holes and strengthening E···F interactions, thus overcoming the negative cooperativity typically associated with multiple PnBs. This remote coordination effect offers a new supramolecular strategy to fine-tune σ-hole depth and Lewis acidity. The steric shielding of the bridgehead in this conformation markedly affects reactivity, as shown by the inhibition of Sb-catalyzed α-hydroxyketone oxidation. These studies illustrate the crucial role of PnBs in stabilizing capsules of this type and modulating their reactivity through conformational control.
PB American Chemical Society
SN 0020-1669
YR 2026
FD 2026
LK https://uvadoc.uva.es/handle/10324/83037
UL https://uvadoc.uva.es/handle/10324/83037
LA eng
NO Inorganic Chemistry, 2025
NO Producción Científica
DS UVaDOC
RD 24-feb-2026