Oxygen Sensing by the Hybrid Langmuir-Blodgett Films of Iridium(III) Complexes and Synthetic Saponite on the Basis of Energy Transfer

Abstract

An ultra-thin hybrid film of amphiphilic iridium(III) complexes and synthetic saponite was manipulated by means of the modified Langmuir-Blodgett method. In the film deposited onto a quartz substrate, the external mixed molecular layer of amphiphilic iridium(III) complexes was reinforced by the inner layer of exfoliated synthetic saponite. As components of the molecular layer, two iridium(III) complexes were used: [Ir(dfppy) 2 (dc9bpy)] + (dfppyH = 2-(4 ,6 -difluorophenyl) pyridine; dc9bpy = 4,4 -dinonyl-2,2 -bipyridine) (denoted as DFPPY) and [Ir(piq) 2 (dc9bpy)] + (piqH = 1-phenyisoquinoline)) denoted as PIQ). The emission spectra from the films changed from blue to red maxima with the decrease of a ratio of DFPPY/PIQ due to the energy transfer from excited DFPPY to PIQ. The intensity of red decreased with the increase of oxygen pressure through the quenching of excited iridium(III) complexes, promising a possibility as an oxygen-sensing film.