Banca de QUALIFICAÇÃO: ISAC CAMILO NOGUEIRA
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : ISAC CAMILO NOGUEIRA
DATE: 17/03/2022
TIME: 15:00
LOCAL: UFSJ
TITLE:
Theoretical Study of Mechanism and Kinetics of Alkylation Reactions of Aromatic Compounds Aiming to Design New Catalysts
KEY WORDS:
Williamson ether synthesis, O-alkylation, C-alkylation, Phenoxide ion, Solvent effect, Friedel-Crafts, Lewis acid
PAGES: 49
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Química Teórica
SUMMARY:
Experiments reported in the literature involving alkylation of the phenol under phase transfer catalysis conditions support the formation of the RN4+PhO–(PhOH) complex in the organic phase. This complex could be directly involved in the transition state. In the present theoretical study, the phase transfer catalyzed alkylation of phenol was investigated using M06-2X calculations and solvent effect using the SMD model combined with reliable experimental single-ion solvation free energy data in aqueous solution. The analysis was done for tetraethylammonium, tetrapropylammonium and tetrabutylammonium phase transfer catalysts. In the case of tetrabutylammoniumion, the calculations have predicted a reaction kinetics compatible with experimental data. In addition, the BuN4+PhO–(PhOH) complex is calculated to be the active species in the catalysis. For the tetraethylammonium and tetrapropylammonium cations, both the RN4+PhO– and RN4+PhO–(PhOH) complexes are not able to explain the catalysis, suggesting that another more complex aggregate can be involved in the process. Using the same methodology in the study of the alkylation reaction of benzene with isopropyl chloride catalyzed by AlCl3, we obtained the exact free energy profile for the feed. We show that the catalyst exists mainly in the form of dimers.
BANKING MEMBERS:
Presidente - 1222762 - ALEX GUTTERRES TARANTO
Externo ao Programa - 1727278 - LUIZ GUSTAVO DE LIMA GUIMARAES
Interno - 1222623 - MARCELO SIQUEIRA VALLE