Experimental Quantification of Halogenâ
â
â
Arene van der Waals Contacts.
Angew Chem Int Ed Engl
; 62(38): e202309682, 2023 Sep 18.
Article
em En
| MEDLINE
| ID: mdl-37470309
ABSTRACT
Crystallographic and computational studies suggest the occurrence of favourable interactions between polarizable arenes and halogen atoms. However, the systematic experimental quantification of halogenâ
â
â
arene interactions in solution has been hindered by the large variance in the steric demands of the halogens. Here we have synthesized molecular balances to quantify halogenâ
â
â
arene contacts in 17 solvents and solvent mixtures using 1 H NMR spectroscopy. Calculations indicate that favourable halogenâ
â
â
arene interactions arise from London dispersion in the gas phase. In contrast, comparison of our experimental measurements with partitioned SAPT0 energies indicate that dispersion is sufficiently attenuated by the solvent that the halogenâ
â
â
arene interaction trend was instead aligned with increasing exchange repulsion as the halogen increased in size (ΔGX â
â
â
Ph =0 to +1.5â
kJ mol-1 ). Halogenâ
â
â
arene contacts were slightly less disfavoured in solvents with higher solvophobicities and lower polarizabilities, but strikingly, were always less favoured than CH3 â
â
â
arene contacts (ΔGMe â
â
â
Ph =0 to -1.4â
kJ mol-1 ).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Reino Unido