Difluorobenzenes revisited: an experimental and theoretical study of spin-spin coupling constants for 1,2-, 1,3-, and 1,4-difluorobenzene.
The experimental spin-spin coupling constants (SSCCs) for 1,3- and 1,4-difluorobenzene have been determined anew, and found to be consistent with previously determined values. SSCCs for 1,2-, 1,3-, and 1,4-difluorobenzene have been analyzed by comparing them with the coupling constants computed using the second-order polarization propagator approximation (SOPPA) and the equation-of-motion coupled cluster singles and doubles method (EOM-CCSD). Eighty experimental values have been analyzed using SOPPA calculations, and a subset of 40 values using both SOPPA and EOM-CCSD approaches. One-bond coupling constants (1)J(C-C) and (1)J(C-F) are better described by EOM-CCSD, whereas one-bond (1)J(C-H) values are better described by SOPPA. An empirical equation is presented which allows for the prediction of unknown coupling constants from computed SOPPA values. A similar approach may prove useful for predicting coupling constants in larger systems.
Alkorta
Ibon
I
Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain. ibon@iqm.csic.es
Blanco
Fernando
F
Del Bene
Janet E
JE
Elguero
José
J
Hernández-Folgado
Laura
L
Jimeno
María-Luisa
ML
D003198:Computer Simulation; D005464:Fluorobenzenes / Q000737:chemistry*; D015394:Molecular Structure
D005464:Fluorobenzenes