Complexes [Pd(Cl)(μ-Cl)(P(CCFc)R 2 )] 2 (Fc = (η 5 -C 5 H 4 )(η 5 -C 5 H 5 ); 6e, R = t Bu; 6f, R = c C 6 H 11 ) and [PdCl 2 (P(CCFc)R 2 ) 2 ] (7a, R = C 6 H 5 ; 7b, R = 2-MeC 6 H 4 ; 7c, R = 2,4,6-Me 3 C 6 H 2 ; 7d, R = c C 4 H 3 O; 7e, R = t Bu; 7f, R = c C 6 H 11 ) are accessible by the reaction of P(CCFc)R 2 (3a–f) with either [PdCl 2 (cod)] (5) (cod = cyclo-1,5-octadiene) or [PdCl 2 (SEt 2 ) 2 ] (8). The spectroscopic, mass-spectrometric and cyclovoltammetric data of 6 and 7 were investigated and the structures of four complexes (6e, 6f, 7b, 7c) in the solid state determined. Complexes 7a–f are mononuclear with palladium in a square-planar environment and show a cis- (7b) or trans-configuration (7c) with linear FcCCP moieties in the solid state. In contrast, 6e and 6f are forming dimers with a planar Pd 2 P 2 Cl 2 (μ-Cl) 2 core with the ferrocenylethynyl ligands positioned above and below this plane. Electrochemical studies of phosphines 3a–3f and the appropriate seleno phosphines 4a–4f show after oxidation follow-up reactions, while a reversible behavior is found for the corresponding palladium complexes 6 and 7. UV–Vis/NIR and IR spectro–electrochemical measurements of 7f indicate moderate electronic interactions between the ferrocenyl units. All complexes are catalytically active in Heck (reaction of iodo benzene with tert-butyl acrylate) and Suzuki (2-bromo toluene or 4′-chloro acetophenone with phenyl boronic acid) C,C cross-couplings. The influence of the electronic ( 1 J( 31 P– 77 Se)) and the steric (Tolman cone angle) properties of the phosphine ligands on the activity of the respective palladium catalysts will be discussed.