Assembly of Heterometallic AuICu 2 I 2 Cores on the Scaffold of NPPN-Bridging Cyclic Bisphosphine.

The row of metallocyclic dinuclear gold(I) complexes with cyclic diphosphines, namely, P-pyridylethyl-substituted 1,5-diaza-3,7-diphosphacyclooctanes, has been obtained. Further interaction of the dinuclear gold(I) complexes with copper(I) iodide gave the first examples of hexanuclear Au ^I /Cu ^I complexes containing two unusual trinuclear AuICu ₂ I ₂ fragments. The structures of di- and hexanuclear complexes were confirmed by NMR spectroscopy, ESI mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. All of the obtained complexes are moderate emitters in the solid state. Dinuclear gold(I) complexes displayed a greenish emission with the maxima in the emission spectra at ca. 550 nm. The obtained hexanuclear heterobimetallic Au ^I /Cu ^I complexes are triplet solid-state blue emitters with the maximum in the emission spectra at 463 and 484 nm. According to the TD-DFT calculations, the observed emission of all studied complexes had a triplet origin and was caused by the ³ CC or ³ (MLCT) T ₁ → S ₀ transitions for dinuclear and hexanuclear complexes, respectively.