Sulfide‐Induced Dimerization Versus Demetallation of Tricopper(I) Clusters Protected by Tris‐Thiolato Metalloligands

Here, we report the reactivity of copper(I) clusters toward sulfide ions; these sulfide copper(I) clusters have attracted much attention due to their relevance to biologically active centers and their fascinating structural and photophysical properties. Treatment of the CuI3RhIII2 pentanuclear complex, [Cu3{Rh(aet)3}2]3+ (aet=2‐aminoethanethiolate), in which a {CuI3}3+ cluster moiety is bound by two fac‐[Rh(aet)3] metalloligands, with NaSH in water produced the CuI6RhIII4 decanuclear complex, [Cu6S{Rh(aet)3}4]4+, accompanied by the dimerization of [Cu3{Rh(aet)3}2]3+ and the incorporation of a sulfide ion at the center. While similar treatment using the analogous CuI3IrIII2 complex with fac‐[Ir(aet)3] metalloligands, [Cu3{Ir(aet)3}2]3+, produced the isostructural CuI6IrIII4 decanuclear complex, [Cu6S{Ir(aet)3}4]4+, the use of the CuI3RhIII2 complex with fac‐[Rh(apt)3] metalloligands, [Cu3{Rh(apt)3}2]3+ (apt=3‐aminopropanethiolate), resulted in the removal of one of the three CuI atoms from {CuI3}3+ to afford the CuI2RhIII2 tetranuclear complex, [Cu2{Rh(apt)3}2]2+. The {CuI3}3+ moiety supported by two octahedral metalloligands with 5‐membered vs. 6‐membered N,S‐chelate rings is converted to {CuI6S}4+ vs. {CuI2}2+ by reacting with S2−, showing that the sulfide‐induced structural expansion vs. contraction is regulated by the small difference in the chelated ring sizes.