[A comparative study on the resolution of second derivative and Fourier self-deconvolution].

Infrared spectra of 2-alkyl-7,7,8,8-tetracyanoquinodimethane (C12H25 TCNQ, C15H31 TCNQ, C18H37 TCNQ) were measured with the resolution of 1 and 4 cm(-1). In order to identify the peak number correctly in the CH2 stretching region, second derivative and Fourier self-deconvolution were applied to the infrared spectra, respectively. The overlapping bands in the CH2 stretching region could be identified when the infrared spectra, which were measured with the resolution of 4 cm(-1), were dealt with by Fourier self-deconvolution. However, the bands overlapped in the CH2 symmetric stretching region could not be observed when these infrared spectra were dealt with by second derivative. The above results reveal that Fourier self-deconvolution method is more powerful than second derivative in identifying bands that are involved in an overlapping band feature.