Structure and luminescence of copper(I) cyanide–amine and –sulfide networks

Copper(I) cyanide reacts with various liquid amines and sulfides (L) under solvent-less conditions to form (CuCN)Ln, n = 0.5, 0.57, 0.75, 0.8, 1, 1.25, 1.5, 2. New X-ray structures are reported for L = Py (Py = pyridine, n = 0.57), 2-MePy (n = 1), 3-EtPy (n = 1.5), 2-ClPy (n = 1), 3-ClPy (n = 2), 3-MeOPy (n = 2), 4-tBuPy (n = 1.5), piperidine (n = 1.25), N-methylmorpholine (n = 1), N,N-dimethylcyclohexylamine (n = 1), 1-methylimidazole (n = 3), Me2S (n = 1), and tetrahydrothiophene (n = 1). The amine structures (except for the monomeric 1-methylimidazole complex) reveal 1D CuCN chains decorated with 0–2 L per metal atom. Chain structures observed include zigzag, helical and figure-8 helical. The CuCN-sulfide structures show sulfur-bridging of CuCN chains. In some cases (CuCN)L⩾1.5 species are transformed to (CuCN)L under vacuum. Thermal analysis shows facile release of ligand, yielding CuCN. Most of the (CuCN)Ln products are photoluminescent, emitting in the visible region. In some cases, coordination of very similar amines results in remarkably different emission spectra.