Thermoregulated Phase-transfer Ligands and Catalysis( XVI ) - Kinetics Investigation of CO Selective Reduction of Aromatic Nitro Compounds Catalyzed by Rh/PETPP in Two-phasic System

The nonionic water-soluble phosphine ligand P[C₆H₄-p-(OC₂H₄)₆OH] ₃ (PETP)/Rh complex termed the thermoregulated phase-transfer catalysis(TRPTC) was applied to CO selective reduction of nitroarenes compounds in the aqueous/organic two-phase. Using o-ClC₆H₄NO₂ as a substrate, the influences of the reaction temperature, CO pressure, concentration of substrate, concentration of catalyst and volume ratio of aqueous to organic on the catalyst properties were studied. Under the conditions 423 K, pco = 4 MPa and t = 32 h, the conversions of o-ClC₆H₄NO₂ were 98% and the selectivity for the corresponding amine was higher than 99%. The kinetics investigation suggested that first-order dependence was observed for the effect of the concentration of catalyst and o-ClC₆H₄NO₂. The apparent activation energy was 131. 13 kJ/mol.