Proximity effects on (1)J(CH) couplings are studied from a theoretical point of view in the following systems: CH4/FH (A) and H2O/HCN (B) which form dimers by hydrogen-bond interactions. (1)J(CH) couplings for different intermolecular distances are calculated for the C-H bond facing the atom bearing lone pairs. While in the former system, this coupling is increased owing to the proximity to the F atom; in the latter this coupling is decreased owing to the proximity to the O atom. These opposite trends are accompanied by slight shortening and lengthening, respectively, of the corresponding C-H bond lengths. As part of this work, measurements of (1)J(CH) couplings in 9-(1,3-dioxolan-2-yl)-1,2,3,4-tetrafluorotriptycene (I) and 1-formyl-2-hydroxy-8-fluoronaphthalene (II) and (1)J(NH) in o-fluorobenzamide (III), showing proximity effects as those described above are carried out. These results suggest that (1)J(XH) couplings are adequate probes to distinguish two different types of X-H...Y hydrogen bonds.

Proximity Effects On Nuclear Spin-spin Coupling-constants .1. (1)j(ch) Couplings In the Vicinity of An Atom Bearing Lone Pairs

ZANASI, Riccardo;
1994-01-01

Abstract

Proximity effects on (1)J(CH) couplings are studied from a theoretical point of view in the following systems: CH4/FH (A) and H2O/HCN (B) which form dimers by hydrogen-bond interactions. (1)J(CH) couplings for different intermolecular distances are calculated for the C-H bond facing the atom bearing lone pairs. While in the former system, this coupling is increased owing to the proximity to the F atom; in the latter this coupling is decreased owing to the proximity to the O atom. These opposite trends are accompanied by slight shortening and lengthening, respectively, of the corresponding C-H bond lengths. As part of this work, measurements of (1)J(CH) couplings in 9-(1,3-dioxolan-2-yl)-1,2,3,4-tetrafluorotriptycene (I) and 1-formyl-2-hydroxy-8-fluoronaphthalene (II) and (1)J(NH) in o-fluorobenzamide (III), showing proximity effects as those described above are carried out. These results suggest that (1)J(XH) couplings are adequate probes to distinguish two different types of X-H...Y hydrogen bonds.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/3133120
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 73
  • ???jsp.display-item.citation.isi??? 79
social impact