Nature of hydride and halide encapsulation in Ag8 cages: insights from the structure and interaction energy of [Ag8(X){S2P(OiPr)2}6]+ (X = H−, F−, Cl−, Br−, I−) from relativistic DFT calculations

Autor: P.L. Rodríguez-Kessler, Renato L. T. Parreira, Raul Guajardo‐Maturana, Alvaro Muñoz-Castro, Giovanni F. Caramori, Alexandre O. Ortolan
Rok vydání: 2022
Předmět:
Zdroj: Physical Chemistry Chemical Physics. 24:452-458
ISSN: 1463-9084
1463-9076
Popis: Unraveling the different contributing terms to an efficient anion encapsulation is a relevant issue pursuing a further understanding of the underlying factors governing the formation of endohedral species. Here, we explore the favorable encapsulation of hydride and halide anions in the [Ag8(X){S2P(OPr)2}6]+ (X- = H, 1, F, 2, Cl, 3, Br, 4, and, I, 5) series on the basis of relativistic DFT-D level of theory. The resulting Ag8-X interaction is sizable, which decreases along the series as: -232.2 (1) > -192.1 (2) > -165.5 (3) > -158.0 (4) > -144.2 kcal⸱mol-1 (5), denoting a more favorable inclusion of hydride and fluoride anions within the silver cage. Such interaction is mainly stabilized by the high contribution from electrostatic type interactions (80.9% av.), with a lesser extend contribution from charge-transfer (17.4% av.) and London type interactions (1.7% av.). Moreover, the ionic character of the electrostatic contributions decreases from 90.7% for the hydride case to 68.6% for the iodide counterpart, in line with the decrease in hardness according to the HSAB Pearson’s concept, owing to the major role of higher electrostatic interaction terms related to softer (Lewis) bases. Lastly, the [Ag8{S2P(OPr)2}6]2+ cluster is able to adapt its geometry in order to maximize the interaction towards the respective monoatomic anion, exhibiting structural flexibility. Such insights shed light into the physical reasoning, necessary for a better understanding of the different stabilizing and destabilizing contributions related to metal-based cavities towards the favorable incorporation of different monoatomic anions.
Databáze: OpenAIRE