From Cluster to Polymer: Ligand Cone Angle Controlled Syntheses and Structures of Copper(I) Alkynyl Complexes

Article abstract of DOI:10.1002/anie.201604762

Copper(I) alkynyl complexes have attracted tremendous attention in structural studies, as luminescent materials, and in catalysis, and homoleptic complexes have been reported to form polymers or large clusters. Herein, six unprecedented structures of Cu^Ialkynyl complexes and a procedure to measure the cone angles of alkynyl ligands based on the crystal structures of these complexes are reported. An increase of the alkynyl cone angle in the complexes leads to a modulation of the structures from polymeric [((PhC≡CC≡C)Cu)₂(NH₃)]_∞, to a large cluster [(TripC≡CC≡C)Cu]₂₀(MeCN)₄, to a relatively small cluster [(TripC≡C)Cu]₈(Trip=2,4,6-iPr₃-C₆H₂). The complexes exhibit yellow-to-red phosphorescence at ambient temperature in the solid state and the luminescence behavior of the Cu₂₀cluster is sensitive to acetonitrile.