Temperature-Mediated Template Release: Facile Growth of Copper(I) Mixed Ethynediide/Isopropylethynide Nanoclusters

In the comproportionation reaction of CuII X2 and Cu0 with isopropylacetylene (iPr-C≡C-H), the ethynediide species C22- is generated via concomitant C-H/C-C bond cleavage of the iPr-C≡C-H precursor under moderate temperature to direct the formation of CuI mixed ethynediide/isopropylethynide nanoclusters (potentially explosive). The active ethynediide dianion C22- exhibits chameleon-like templating behavior to form C2 @Cum (m=6 (3, 4), 7 (2, 4), 8 (1)) central structural units for successive formation of {C22- ⊂Cu24 } (1, 2), {6 C22- ⊂Cu48 } (3), and {18 C22- ⊂Cu92 } (4) complexes. Bearing the highest C22- content, complex 4 features an unprecedented nanoscale Cu2 C2 kernel. Furthermore, 1-3 exhibit structure-controlled photoluminescence in the solid state.