Luminescence thermochromism of two entangled copper-iodide networks with a large temperature-dependent emission shift.

The luminescence thermochromism properties of two entangled copper(I)-iodide coordination polymers formulated [Cu4I4(dmimpr)2]n (1) and [Cu6I6(dimb)3]n (2) (dmimpr = 1,3-di(2-methyl-imidazol-1-yl)propane, dimb = 1,4-di(imidazol-1-yl)butane) are reported. Upon cooling by liquid nitrogen, their solid-state luminescences at room temperature are drastically changed with the large red-shifts of 41 and 78 nm for 1 and 2, respectively. The correlation between luminescence thermochromism and temperature-dependent variation of the Cu···Cu distance is also elucidated.