有机化合物的光谱及激发能存在着良好的同系线性规律。前文曾用HMO法对多联苯体系的同系线性规律进行了讨论,说明了对联多苯的共轭作用比间联多苯强,而后者共轭作用很弱,这可从光谱得到证实。近来,徐光宪等探讨了同系线性规律的量子化学基础,根据多烯中键长交替现象提出了MHMO法,并由此引出了同系能级因 There is a good law of homology for the spectra and excitation energy of organic compounds. The HMO method was used to discuss the homology linear relationship of polybenzene system. It is proved that the conjugation of biphenyl is stronger than that of biphenyl, while the conjugation of the latter is weak. This can be confirmed from the spectra. Recently, Xu Guangxian et al. Discussed the quantum chemical basis of the homology linear law, proposed the MHMO method based on the phenomenon of alternating bond lengths in polyenes, and led to the homomorphism