LAUSR

The design and research of luminescent and volatile organic compounds (VOCs) fluorescent sensing/stimuli–response materials are of great significance and challenge. We report herein a series of new [(Xantphos)CuILN] type complexes with tetrahedral CuIP2N coordination, showing luminescence from blue to red and luminescence sensing for VOCs detection (Xantphos is 4,5‐bis (diphenylphosphino)‐9,9‐dimethylxanthene, LN is N‐containing ligand). Firstly, six new complexes 1–6 were designed and ball‐milling synthesized by the ligand‐addition reaction of a raw material [(Xantphos)CuI] with different N‐containing ligands 2‐aminopyridine (1), 3‐cyanopyridine (2), 4‐cyanopyridine (3), 2‐(3′‐pyridyl)‐benzoxazole (4), 3‐I‐4‐aminopyridine (5), and imidazole (6). Time‐dependent density functional theory (TD‐DFT) calculations assign the low‐energy band (absorption edge) of 1–6 in UV–Vis absorption as a mixed (XL + ML)CT transition, the corresponding (XL + ML)CT excited state is also thought to be the source of photoluminescence (PL). Material 4 has the highest PL efficiency (~44%), which may benefit from its greatest structural rigidity. Material 5 exhibiting the worst PL efficiency should be related to the iodine atom in the LN ligand (I dominate the highest unoccupied orbitals of the S1 and T1 states). Based on its very weak PL, the corresponding thin‐film sensor (5) achieve significantly enhanced luminescence sensing (lighting‐up mode) for pyridine and 4‐methylpyridine vapor. The sensor also achieves the lowest detection limit (LOD = 2.51 ppm) and the fastest response speed (T50 = 30 s) for pyridine. In addition, the series of materials also show interesting quenching and vapochromic luminescence sensing/stimuli–response for a variety of VOCs vapors.