A Se₁₉ Homocycle Complexed by Two Copper(I) Ions

Freshly prepared red selenium and the copper(I) reagent [Cu(1,2-F2C6H4)2][A] are the key to the salts [Cu2Se19][A]2 and [Cu2Se19][A]2⋅0.5 Na[A] ([A]=[Al(ORF)4], RF=C(CF3)3), which provides the first structurally characterized E19 ring of any element E. The unusual [Cu2Se19]2+ ion contains two Cu+ ions that stabilize the C2-symmetric Se19 ring.