Tetra-μ3-iodido-tetra-kis-[(tri-n-butyl-phosphane-κP)copper(I)].

The title complex, [Cu4I4(C12H27P)4], crystallizes with six mol-ecules in the unit cell and with three independent one-third mol-ecule fragments, completed by application of the relevant symmetry operators, in the asymmetric unit. The tetranuclear copper core shows a tetrahedral geometry (site symmetry 3..). The I atoms also form a tetra-hedron, with I⋯I distances of 4.471 (1) Å. Both tetra-hedra show an orientation similar to that of a pair of self-dual platonic bodies. The edges of the I-tetra-hedral structure are capped to the face centers of the Cu-tetra-hedron and vice versa. The Cuface⋯I distances are 2.18 Å (averaged) and the Iface⋯Cu distances are 0.78 Å (averaged). As a geometric consequence of these properties there are eight distorted trigonal-bipyramidal polyhedra evident, wherein each trigonal face builds up the equatorial site and the opposite Cu⋯I positions form the axial site. As expected, the n-butyl moieties are highly flexible, resulting in large elongations of their anisotropic displacement parameters. Some C atoms of the n-butyl groups were needed to fix alternative discrete disordered positions.