Intermolecular Se···I Interactions Identified in Cu11(μ9‐Se)(μ3‐I)3[Se2P(OEt)2]6 Form a One Dimensional Polymeric Chain

The undecanuclear copper cluster Cu₁₁(μ9‐Se)(μ₃‐I)₃[Se₂P(OEt)₂]₆ 1 , has been isolated along with Cu₈(μ₈‐Se)[Se₂P(OEt)₂]₆ 2 , from the reaction of NH₄Se₂P(OEt)₂, Cu(CH₃CN)₄PF₆, and Bu₄NI in a molar ratio of 3:2:2 in diethyl ether. The molecular formulation of 1 was confirmed by elemental analysis, positive FAB mass spectrometry, multinuclear NMR (¹H, ³¹P, and ⁷⁷Se), and X‐ray diffraction. In cluster 1 eleven copper atoms adopt the geometry of a 3,3,4,4,4‐pentacapped trigonal prism with a selenium atom in the center. The coordination geometry for the central, nonacoordinated selenium atom is tricapped trigonal prismatic. In addition, the central core Cu₁₁Se is further stabilized by three iodides and six dsep ligands. Besides, weak inter‐molecular Se···I interactions (3.949–3.972 Å) are uncovered and form a one dimensional polymeric chain.