Layered Luminescent Ag(I) and Cd(II) Coordination Polymers (LCPs) assembled from a new tri-pyridyl Cyclic Triimidazole ligand

Luminescent metal-organic frameworks and coordination polymers (LMOFs and LCPs)1 are a class of very interesting materials that have drawn great attention thanks to their properties. They find application in fields such as the development of biological sensors and light-emitting devices. For these reasons, nowadays, the design of new LCPs is a very active and challenging research area. In this work, we report the synthesis of a new derivative of the cyclic triimidazole (TT)2 molecule, an already known organic scaffold with very interesting luminescence properties. The new ligand (4py)3TT, brings three pyridyl donor groups oriented with a trigonal symmetry and its reactivity has been explored toward the closed-shell Cd(II) and Ag(I) metals. Reaction of (4py)3TT with silver(I) triflate and cadmium(II) nitrate allow us to isolate two new LCPs, [Ag((4py)3TT)(CF3SO3)] (1) and [Cd((4py)3TT)(NO3)2(EtOH)] (2). Compounds 1 and 2 have been characterized by SCXRD, XRPD, IR and photoluminescence spectroscopies. Intriguingly, compound 2 shows mechanochromic luminescence.