Solid-state reactivity of copper(I) iodide: luminescent 2D-coordination polymers of CuI with saturated bidentate nitrogen bases

Solid-state reactions of copper(I) iodide with 1,4-diazabicyclo[2.2.2]octane (DABCO) and piperazine in different conditions (kneading, vapour digestion, thermal treatment) resulted in the formation of four new luminescent systems, which have been characterized via X-ray diffraction and photo-luminescence spectroscopy. At room temperature all compounds exhibit a bright emission in the solid state that markedly shifts bathochromically on cooling to 77 K. The luminescence of the almost isostructural 2D-coordination polymers [Cu2I2(L)(2)](infinity) (L = DABCO, piperazine) exhibits an unusually long lifetime (125 and 53 mu s, respectively), which becomes even longer (609 and 420 mu s, respectively) at 77 K.