Fabrication and Evaluation of Copper(I) Iodide Sensor Substrates

Abstract

Copper(I) iodide and other copper(I) salts (CuX) react with amines and sulfides (L) in their gas phase to form luminescent rhomboid Cu2(�2-X)2L4 and/or cubane Cu4(�3-X)4L4 complexes. This work reports this spontaneous reaction occuring at the surface of CuI powder, pressed CuI pellets, CuI-impregnated polymer films, and CuI-embedded polypropylene plates. An LED fiber optic fluorimeter was used to monitor the reaction of gaseous pyridine (Py) or other nucleophile with CuI-impregnated PVC films. Known Py vapor pressures were established in a sealed chamber through gas-phase dilutions and correlated to luminescence emission response. Detectability of Py was established at vapor pressures as low as 0.001 Torr. Surface phases of CuI-Py were identified through X-ray powder diffraction. Initial formation of dimer Cu2(�2-I)2Py4 (emission l = 520 nm) quickly gives way to tetramer Cu4(�3-I)4Py4 (emission l = 580 nm)