A simple and straightforward synthesis of a new linear trinuclear Cu(I) cluster with polyphosphine ligands is presented. The reaction of this pre-organized Cu3 precursor with En ligand complexes (E = P, As; n = 2, 5) affords discrete complexes exhibiting end-on η(1)-coordination of the E2 ligands or one-dimensional coordination polymers featuring σ-1,3-bridging E5 rings, respectively.