New heterometallic Sn–Cu compound that contains copper atoms in two different oxidation states was obtained by the solid state reaction between Sn(OBut)2 (OBut = tert-butoxide) and Cu(hfac)2 (hfac=hexafluoroacetylacetonate). Single crystal X-ray diffraction study revealed the ionic structure of a compound that can be formulated as {[CuI 3Sn2(OBut)6]+[CuII(hfac)3]−} (1) with no significant interactions between complex cation and anion. The anion is comprised of an octahedrally coordinated by three chelating β-diketonate ligands CuII atom that shows a typical tetragonal Jahn–Teller distortion of the polyhedron. The heterometallic [Cu3Sn2(OBut)6]+ cation features a CuI triangle capped by two Sn(OBut)3 units. All alkoxide ligands are μ 2-bridging between Sn and Cu atoms providing a trigonal pyramidal geometry around tin that is consistent with lone pair SnII centers. An almost perfect triangular copper core is stabilized by cuprophilic interactions, similar to those in other polynuclear CuI compounds. The cation represents the first example of a CuI triangular arrangement that is not supported by μ 3-centering atoms or by μ 2-all-side bridging. Multinuclear NMR studies unambiguously confirm the retention of heterometallic cluster in solution as well as the absence of ligand redistribution between the anion and cation. The use of a mixed-ligand approach creates broad opportunities for designing new heterometallic complexes with unusual architectures that are not observed in homoleptic counterparts.