The studies on X-ray photoelectron spectroscopic shakeup and valence band spectra of o-nitroacetanilide derivatives I (R = H, 2-Me, 3-Me, 4-cyano, 4-MeO, 3-Cl, 3-Br, 4-Br) have been reported. The results show that the splitting of N 1s photoelectron peaks of the nitro group may be related to the intramol. charge-transfer effect between donor and acceptor within the same mol., and the magnitude of intramol. charge-transfer can be estimated by the distance of splitting of N 1s of nitro group or by the relative area ratio of the splitting peaks.

Key words: NITRO COMPOUNDS, X-RAY PHOTOELECTRON SPECTROMETRY, BAND STRUCTURES, CHARGE TRANSFER, VALENCE BANDS, ACETANILIDE