Luminescent copper(I) coordination polymer with 1-methyl-1H-benzotriazole, iodide and acetonitrile as ligands

Simultaneous Occurrence of Vapochromism and Vapoluminescence in Formaldehyde-Responsive Amino-Functionalized Copper(I) Polymorphic Coordination Polymers

The use of vapor-responsive chromic materials in sensing applications for the detection of harmful volatile organic chemicals is rapidly expanding. Herein, four new amino-functionalized Cu(I) coordination polymers of [CuI(pyt-NH₂)]_n (1) and (2) and [CuSCN(pyt-NH₂)]_n (3) and (4) (where pyt-NH₂ = 2-amino-5-(4-pyridinyl)-1,3,4-thiadiazole) were successfully synthesized. Single-crystal X-ray diffraction analysis reveals that 1 and 2 are iodo-based polymorphs, while 3 and 4 are thiocyanato-based polymorphs. They possess densely diverse crystalline architectures decorated by uncoordinated amino groups as a binding site. Also, 1-4 show a variety of color and luminescence based on the structural diversity. Remarkably, 1 and 2 undergo the change of color and naked-eye solid-state luminescence in response to formaldehyde (FA) vapor, demonstrating simultaneous vapochromism and vapoluminescence. The chromic Cu(I) coordination polymers in this work present for the first time dual-mode vapochromism and vapoluminescence in a highly selective response to FA vapor. The responsive mechanism has been clarified by Fourier transform infrared spectroscopy (FT-IR), electrospray ionization mass spectrometry (ESI-MS), ¹H nuclear magnetic resonance (NMR), powder X-ray diffraction (PXRD), and luminescence lifetime measurements, which reveal carbinolamine formation via the specific reaction between FA and the active amino groups of coordinated pyt-NH₂. The carbinolamine formation can trigger the structural transformation of 1 and 2, leading to the concurrently selective vapochromism and vapoluminescence induced by FA vapor.

Visible-emitting Cu(i) complexes with N-functionalized benzotriazole-based ligands

Bidentate benzotriazole-based N-ligands are suited for the preparation of luminescent heteroleptic copper(i) complexes with noticeable emissions related to 3MLCT transitions.

Structural characterization and optical properties of two copper(i)-iodide BODIPY coordination polymers

BODIPY chromophores with pyridyl or pyrimidinyl substituents exhibit strong solid-state fluorescence which is quenched in CuI coordination polymers.