The reactions of tetrahedral molybdenum complexes bearing unsubstituted heterodiatomic Group 15 elements, [Cp2Mo2(CO)(4)(mu,eta(2):eta(2)-PE)] (Cp=C5H5; E=As (1), Sb (2)), with Cu-I halides afforded seven unprecedented neutral supramolecular assemblies. Depending on the Mo2PE units and the Cu-I halide, the oligomers [⟨{Cp2Mo2(CO)(4)}{mu(4),eta(2):eta(2):eta(2):eta(1)-PE}⟩(4)⟨{CuX}{Cu(mu-X)}⟩(2)] (E=As (X=Cl (3), Br (4)); E=Sb (X=Cl (6), Br (7))) or the 1D coordination polymers [{Cp2Mo2(CO)(4)}{mu(4),eta(2):eta(2):eta(1):eta(1)-PAs}{Cu(mu-I)}](n) (5) and [{Cp2Mo2(CO)(4)}{mu(4),eta(2):eta(2):eta(2):eta(1)-PSb}(2){Cu(mu-X)}(3)](n) (X=I (8), Br (9)) are accessible. These solid-state aggregates are the first and only examples featuring the organometallic heterodiatomic Mo2PE complexes 1 and 2 as linking moieties. DFT calculations demonstrate that complexes 1 and 2 present a unique class of mixed-donor ligands coordinating to Cu-I centers via the P lone pair and the P-E sigma-bond, revealing an unprecedented coordination mode.