Protonated and methylated dimethyl sulfoxide cations and dications. DFT/GIAO-MP2 NMR studies and comparison with experimental data.
Energies, electronic structures, and thermodynamics of protonated and methylated dimethyl sulfoxide (DMSO) cations and dications were calculated using the density functional theory (DFT) method. The O-protonated structure 2 was found to be 37.0 kcal/mol more stable than the S-protonated 3. For diprotonated DMSO dication, the O, O-diprotonated form 6 was found to be the global minimum, more stable by 20.8 kcal/mol than O,S-diprotonated 7. Interestingly, for dimethylated DMSO dication, O,O-dimethylated 11 and O,S-dimethylated 12 are isoenergetic. (13)C, (17)O, and (33)S NMR chemical shifts of the cations and dications were calculated using the GIAO-MP2 method and compared with the available experimental data.
Rasul
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G
Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles, California 90089-1661, USA.
Prakash
G K
GK
Olah
G A
GA