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A quantum chemical calculation has been performed for complexes of a cadmium or mercury atom with ammonia by using relativistic effective core potentials (RECPs). It was shown that the luminescence from the exciplexes of the excited complexes was in good agreement with the experimental observations. The spin-orbit configuration interaction (SOCI) calculations showed that for Cd-NH, , the energy difference between the ,A, and ,A, states was too small to determine the emission state. On the other hand, for Hg-NH,, the energy difference was relatively large because of a relativistic effect. These results are consistent with the experimental observations .

The fluorescence of some aliphatic diamines was studied in the gas phase and in some solvents at several temperatures. It was found that N,N,Nf,N'-tetramethylpropane-1,3-diamine (TMPD) and N , N , N , Ntetramethylbutane-l,4-diamine (TMBD) have two emission bands in the gas phase. TMBD also shows two bands in solution. These bands were assigned previously to an excited monomer and an intramolecular excimer. From the temperature dependence of the intensity ratio of the two bands, the enthalpy changes for the excimer formation were evaluated. The stability of the cyclic excimer is discussed in terms of the ring size effect and the solvent effect on the band positions.