Abstract
| - A synchrotron radiation source was utilized for X-ray photoelectron spectroscopic analysis of anitrobenzaldimine-formed monolayer. The N(1s) peak intensity for the nitro group becomes reduced uponX-ray irradiation, while C(1s) and O(1s) peaks are invariant. This observation indicates that the nitrogroup is cleaved selectively, leaving the phenyl ring intact in the layer. The cleavage rate is measuredas a function of photon energy and normalized with the photon flux. The cleavage is first-order to theconcentration of the nitro group. The rate constant is independent of the incident photon energy, suggestingthat the cleavage is not associated with a direct photoexcitation of atomic core electrons. Electrons ejectedby the X-ray are proposed as the most viable cause for the bond cleavage. The molecules remaining onthe irradiated surface were analyzed with gas chromatography−mass spectrometry coupled with thesolid-phase microextraction method after hydrolyzing the imine bond. It is found that the amount ofnitrobenzaldehyde is reduced upon the irradiation, but the expected products, benzaldehyde andhydroxybenzaldehyde, are not produced.
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