[RhCl(TDA)(3)], [RhCl(HA)(3)]. [PdCl2(TDA)2] and [PdC1(2)(HA)(2)] (TDA = tridecylamine, HA = hexylamine) were synthesized and tested as catalysts in homogeneous and heterogeneous condition for the 1-heptyne semihydrogenation, using gamma-alumina as support. The Lindlar catalyst was used as a reference. XPS, FTIR and Atomic Absorption results showed that the active catalytic species in each case is the complex itself. All of the catalytic systems exhibited a better performance than the Lindlar catalyst, with the exception of [PdCl2(HA)(2)]. The analysis of activity and selectivity values allowed to say that the best system is [RhCl(TDA)(3)]/Al2O3, an heterogeneous catalyst with an electron-rich transition metal and an electron-donating ligand (TDA) containing a long-chain hydrocarbon substituent. The complex system catalytic behaviour could be explained by means of electronic a id geometric effects. (C) 2007 Elsevier B.V. All rights reserved.