A newly oxospiro[indoline-3,4 '-pyran]-5 '-carbonitrile derivative has been synthesized and characterized by FTIR, NMR spectroscopies, and elemental analysis. The compound thin film form has been prepared by spin coating technique. The optical absorbance, transmittance, and reflectance measurements were carried out in the wavelength (300-2500 nm) range. The absorption and dielectric parameters were determined and discussed. The electronic transition energies (2.56, 3.45& 3.97 eV) were deduced and correlated to the onset, optical, and transport gaps, respectively. The electrical resistance and Seebeck coefficient measurements revealed the n-type semiconducting behavior of the films. The detected rapid reversibility of the O2 - chemisorption process on the surface of the present films at room temperature was exploited for the NH3 gas sensing application. The revealed fast reversibility, low response (180/224 s) and recovery (3 s) times, good selectivity, as well as the long-term stability of the present films, prove their promises for RT-NH3 gas sensing applications.
