New anthracene-based Cu(I) dithiocarbamates as AIEgens

Abstract

The syntheses and structural characterizations of a series of anthracene-tethered Cu(I) phosphine dithiocarbamate complexes, [CuL(PPh3)2], are described in this article. All complexes were readily prepared from corresponding ligands with various acyclic and cyclic N-alkyl substituents and [Cu(PPh3)2(NO3)]. Steric hindrance imposed on the anthracenyl rings by dithiocarbamate, N-alkyl substituents and triphenylphosphine moieties in complexes 1-6 are not detected, as evidenced by the sharp aromatic resonances in 1H NMR spectra. X-ray crystallography reveals distorted tetrahedral chelation environments around the Cu(I) centers in 2 and 3 as well as extensive C–S···π and C–H···π intermolecular interactions in their solid state packings. The complexes display characteristic anthracene-based absorption and emission properties. The emission quantum yields of the complexes are poor (1.0–2.7 × 10−2) but the aggregation-induced emission effects are perceived in aqueous DMSO solutions. Especially, 6 with N-substituted cyclohexyl group displays the largest increase in emission intensity (ca. 7 times).