Pregled bibliografske jedinice broj: 43278
Predictions of 13C Chemical Shifts in Carbocations. The Use of Scaled Chemical Shifts Calculated Using GIAO DFT Methods.
Predictions of 13C Chemical Shifts in Carbocations. The Use of Scaled Chemical Shifts Calculated Using GIAO DFT Methods. // Journal of the Chemical Society, Perkin Transactions 2., 2 (1999), 1317-1321 (međunarodna recenzija, članak, znanstveni)
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Naslov
Predictions of 13C Chemical Shifts in Carbocations. The Use of Scaled Chemical Shifts Calculated Using GIAO DFT Methods.
Autori
Vrček, Valerije ; Kronja, Olga ; Siehl ; Hans-Ullrich.
Izvornik
Journal of the Chemical Society, Perkin Transactions 2. 2
(1999);
1317-1321
Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni
Sažetak
Accurate prediction of 13C chemical shifts (delta pred) for the +^C and the alpha- and beta-carbon atoms in alkyl and cycloalkyl carbocations is achieved through scaling. Ab initio calculated chemical shifts (delta calc) at the GIAO-B3LYP/6-311g(d,p)//B3LYP/6-31G(d) level of theory for 16 different carbocations are scaled using a linear correlation equation (delta pred=adelta calc+b). The slope and intercep a and b were determined separately for +^C and the alpha- and beta-carbon positions, and were found to be different for cation structures preferentially stabilized by beta-C-H and beta-C-C hyperconjugation. A very good correlation of all predicted and experimental chemical shifts is obtained (a=0.999 +/-0.022, b=0.231 +/- 0.320). Preliminary results indicate that scaling using linear correlations can also be applied to the +^C carbon chemical shift in benzyl type carbocations.
Izvorni jezik
Engleski
Znanstvena područja
Kemija
Citiraj ovu publikaciju:
Časopis indeksira:
- Current Contents Connect (CCC)
- Web of Science Core Collection (WoSCC)
- SCI-EXP, SSCI i/ili A&HCI
