Terminal and Non Terminal Alkynes Partial Hydrogenation Catalyzed by Some d8 Transition Metal Complexes in Homogeneous and Heterogeneous Systems

DOMINGO LIPRANDI; EDGARDO CAGNOLA; CECILIA R. LEDERHOS; JUAN M. BADANO; MÓNICA E. QUIROGA

Hydrogenation

Intech

Año: 2012; p. 137 - 159

[PdCl2(NH2(CH2)12CH3)2] and [RhCl(NH2(CH2)12CH3)3] were synthesized and tested as catalysts in homogeneous and heterogeneous condition for 1-heptyne or 3-hexyne partial hydrogenation using -Al2O3 or RX3 (a carbonaceous material) as support at mild operational conditions (P = 150 kPa and T up to 303K). The Lindar catalyst was used as a reference. Elemental Composition, XPS, IR and Absorption Spectroscopy results showed that the active catalytic species in each case was the complex itself. All of the catalytic systems exhibited a better performance than the Lindar Catalyst. The analysis of activity and selectivity values allowed to say that de optimum system is the [RhCl(NH2(CH2)12CH3)3] either on -Al2O3 or RX3, an heterogeneous catalyst with an electron-rich transition metal and a high content of an electron-donating ligand (NH2(CH2)12CH3) with a long chain hydrocarbon substituent. The complex catalytic behaviour could be explained by means of electronic and geometric effects.