Obtaining 1-heptene from 1-heptyne semihydrogenation with an anchored rhodium complex on different supports as catalyst

QUIROGA , M.E.; LIPRANDI, D.A.; L'ARGENTIERE, P.; CAGNOLA, E.A.

JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY

Society of Chemical Industry - John Wiley & Sons, Ltd.

Lugar: Norwich; Año: 2005 vol. 80 p. 158 - 163

0268-2575

The complex [RhCl(NH2(CH2)12CH3)3] was tested for the semihydrogenation of 1-heptyne in homogeneous and heterogeneous conditions. g-Al2O3 and two different commercial activated carbons (RX-3 EXTRA and GF- 45) were used as supports. The results were, then, compared with those previously reported for the [PdCl2(NH2(CH2)12CH3)2] complex supported or unsupported, and with the results obtained with the classic Lindlar catalyst. The complex was characterised by FTIR and elemental analysis. The pure species and the supported one were also characterised by X-ray photoelectron spectroscopy (XPS). Results determined by the last mentioned technique suggest that the active species is the complex itself, which is stable under the reaction conditions. The supported rhodium tetra-coordinated complex shows higher activity and selectivity than the same complex unsupported, and also than the classic Lindlar catalyst. Moreover, among the rhodium-supported complexes the one  immobilised on RX-3 EXTRA has a better performance than that heterogenised on GF-45, and this one has a better activity and selectivity  than the g-Al2O3 anchored  complex. Our results also show that under the same operational conditions (temperature, hydrogen pressure and metal/substrate weight ratio) the rhodium complex, unsupported or supported, has  a better performance than the corresponding palladium complex.