Large spin-dipolar long-range F-F coupling constants in conjugative compounds: their study using propagators
para-Difluorobenzene (I) and 1,1,4,4-tetra-fluoro-1,3-butadiene (II) were studied as model compounds in order to obtain an insight into the factors determining the large values of long- {A figure is presented} range F-F couplings which are known for conjugated systems. The role played by the π-elect...
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| Autores principales: | , , |
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| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_01661280_v210_nC_p205_Peruchena |
| Aporte de: |
| Sumario: | para-Difluorobenzene (I) and 1,1,4,4-tetra-fluoro-1,3-butadiene (II) were studied as model compounds in order to obtain an insight into the factors determining the large values of long- {A figure is presented} range F-F couplings which are known for conjugated systems. The role played by the π-electronic system in transmitting the spin information associated with the Fermi contact (FC), the spindipolar (SD) and the paramagnetic spin-orbital (PSO) interactions was evaluated using the inner projections of the polarization propagator technique (IPPP). The important SD contributions to such couplings were analysed using the contributions from localized molecular orbitais within the polarization propagator approach (CLOPPA) method. Comparison of analogous coupling pathways in I and II indicates that a conjugated system is more efficient in transmitting the SD coupling the more "concentrated" is the π-electronic system. This behaviour parallels that known for the FC interaction in long-range H-H couplings. © 1990. |
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