Highly Luminescent Octanuclear Au-I-Cu-I Clusters Adopting Two Structural Motifs: The Effect of Aliphatic Alkynyl Ligands

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Igor O. Koshevoy
  • Chia-Li Lin
  • Antti Karttunen

  • Janne Jänis
  • Matti Haukka
  • Sergey P. Tunik
  • Pi-Tai Chou
  • Tapani A. Pakkanen

Research units

  • University of Eastern Finland
  • National Taiwan University
  • St. Petersburg State University

Abstract

Reactions of the homoleptic (AuC2R)(n) precursors with stoichiometric amount of diphosphine ligand PPh2C6H4PPh2 ((PP)-P-boolean AND) and Cu+ ions lead to an assembly of a new family of bimetallic clusters [Au6Cu2(C2R)(6)-((PP)-P-boolean AND)(2)](2+) (type I; R=9-fluorenolyl (1), diphenylmethanolyl (2), 2,6-dimethyl-4-heptanolyl (3), 1-cyclohexanolyl (4), Cy (5), tBu (6)). In the case of R=1cyclohexanolyl, a structurally different complex [Au6Cu2(C2C6H11O)(6)((PP)-P-boolean AND)(3)](2+) (7, type II) could be obtained by treatment of 4 with one equivalent of the diphosphine, while for R=isopropanol-yl only the latter type of cluster [Au6Cu2(C2C3H7O)(6)((PP)-P-boolean AND)(3)](2+) (8) was detected. Steric bulkiness of the alkynyl ligands and O center dot center dot center dot H-O hydrogen bonding are suggested to play an important role in stabilizing the type I and type II cluster structural motif, respectively. All the complexes exhibit intense photoluminescence in solution with emission parameters that depending on the geometrical arrangement of the octanuclear metal core. The clusters 1-4 and 6 show single emission band in a blue region (469-488 nm) with maximum quantum yield of 94% (4), while structurally different 7 and 8 emit yellow-orange (590 nm) with unity quantum efficiency. The theoretical DFT calculations of the electronic structures have been carried out to demonstrate that the metal-centered triplet emission within the heterometallic core plays a key role for the observed phosphorescence.

Details

Original languageEnglish
Pages (from-to)11456-11466
Number of pages11
JournalCHEMISTRY: A EUROPEAN JOURNAL
Volume17
Issue number41
Publication statusPublished - Oct 2011
MoE publication typeA1 Journal article-refereed

    Research areas

  • alkyne ligands, cluster compounds, copper, gold, luminescence, APPROXIMATE COULOMB POTENTIALS, DENSITY-FUNCTIONAL METHODS, AUXILIARY BASIS-SETS, AG-I, GOLD(I)-SILVER(I) CLUSTER, COMPLEXES, GOLD(I), GOLD(I)-COPPER(I), ENERGY, ARYLACETYLIDES

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