英語翻譯
In the case of the p-nitroaniline anion,the transition between the HOMO and the LUMO corresponds to the 9b2-5b1 transition and is therefore symmetry-forbidden.The observed long-wave absorption band of the pnitroaniline anion probably corresponds to the 4b i-5b 1 transition with the same redistribution of electron density
as in the case of p-nitroaniline.Similarly,it follows from the calculations that for p-nitroaniline protonated in the ring,the long-wave band is due to the transition 17a'--18a",for the forms of nitroaniline protonated at the nitro-group and with transfer of a proton from the amino-group to the nitro-group it corresponds to the transition 6 a ' - - 7 a ' ,and for the nitroanilinium ion it corresponds to the transition 10a'~16a".The energies of these transitions are given in Table 1.It can be seen that the attachment of a proton to the nitro-group or the removal of a proton from the amino-group leads to a long-wave displacement of the long-wave band of p-nitroaniline.The band of p-nitroaniline is displaced in the same direction when a proton is transferred from the amino-group to the nitro-group.The attachment of a proton to the amino-group or to the center of the benzene ring produces a short-wave displacement of the long-wave band.