Publikace detail

Reparametrization and/or Determination of Hammett, Inductive, Mesomeric and AISE substituent constants for five Substituents: N+(CH3)3. CH2N+(CH3)3, CH2Py+, CH2SO2CH3 and PO(OCH3)2.

Autoři: Pícha Jan | Cibulka Radek | Liška František | Pařík Patrik | Pytela Oldřich

Rok: 2004

Druh publikace: článek v odborném periodiku

Název zdroje: Collection of Czechoslovak Chemical Communications

Název nakladatele: Ústav organické chemie a biochemie AV ČR

Místo vydání: Praha

Strana od-do: 2239-2252

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
cze	Reparametrizace a určení Hammettových, induktivních, mesomerních a AISE substitučních konstant pro pět substituentů N+(CH3)3. CH2N+(CH3)3, CH2Py+, CH2SO2CH3 and PO(OCH3)2.	Nevyplněno	Dissociation constants, Benzoic acids, Substituent effects, Hammett equation, AISE, Quarternaly ammonium salts, Sulfones, Phosphonates
eng	Reparametrization and/or Determination of Hammett, Inductive, Mesomeric and AISE substituent constants for five Substituents: N+(CH3)3. CH2N+(CH3)3, CH2Py+, CH2SO2CH3 and PO(OCH3)2.	Ten meta and para substituted benzoic acid with substituents N+(CH3)3, CH2N+(CH3)3, CH2Py+, CH2SO2CH3 a PO(OCH3)2 were synthesized. Dissociation constants of these acids were determined in five solvents (water, ethanol, methanol, N,N-dimethylformamide, dimethylsulfoxide). Dissociation constants of benzoic acid derivatives with other substituents H, CH3, NHCOCH3, OCH3, F, Cl, Br, I, COCH3, CN, NO2, SO2CH3 were taken from the literature (calibration set). Substituent constants sigma_m, sigma_p, sigma_I, sigma_R a sigma_i for substituents N+(CH3)3, CH2N+(CH3)3, CH2Py+, CH2SO2CH3 a PO(OCH3)2 were calculated by nonlinear and PLS (partial least square, method with latent variables) calibration in three correlation models using calibration set. Nonlinear regression appears more suitable and more universal in comparison with PLS calibration. The advantage of nonlinear regression is independence on missing data in the solvent, evaluation of precision (standard deviation), the accessibility of necessary software, and easy calculation. However, on the contrary of PLS calibration, this procedure fails in calculation of substituent constants with description of properties of substituents (substituent constants sigma_I, sigma_R). The obtained values of substituent constants are in good agreement with those published in the literature.	Dissociation constants, Benzoic acids, Substituent effects, Hammett equation, AISE, Quarternaly ammonium salts, Sulfones, Phosphonates

Search

Přihlášení pro studenty

Přihlášení pro zaměstnance

Publikace detail

Katedry

Ústavy a pracoviště

Jak nás najdete?

Služby

Často hledáte