[en] Dimeric metallamacrocycles of 2 : 2 (metal-to-ligand) stoichiometry, [Pd{α,ω-bis(diphenylphosphino)oligothienylene} Cl_2]_2 1-3 were prepared from a self-assembly reaction of [Pd(CH_3CN)_2Cl_2] and α,ω-bis- (diphenylphosphino)oligothienylene in 90-94% yields. The structures of metallamacrocycles 1-3 were determined by X-ray diffraction. 1 crystallizes in the monoclinic space group P2_1/n with a/A = 12.0737(13), b/A = 17.1993(18), c/A = 13.0951(14) and β / .deg. = 101.505(2). 2 crystallizes in the triclinic space group P with a/A = 10.2634(4), b/A = 19.7855(9), c/A = 21.0851(9), α / .deg. = 63.1010(10), β / .deg. = 86.5880(10), γ / .deg. = 81.2280(10). 3 crystallizes in the triclinic space group P with a/A = 10.4353(19), b/A = 13.482(3), c/A = 13.816(3), α / .deg. = 108.027(4), β / .deg. = 90.461(4), γ / .deg. = 93.261(4). The UV spectra of 1-3 were characterized