Luminescence action spectrum

The insulating action of the —CH2— group between the phenyl ring and the amino radical in benzylamine can be inferred from another group of experiments. It is well known that under vacuum u.v. irradiation of NH3 and the aliphatic amines the emission spectrum of the excited NH2 radical (a-band system) has been observed.26 Attempts in this laboratory to produce the same luminescent photodissociation in aniline vapor have so far failed. On the other hand, in benzylamine vapor the bands of the -NHj radical are easily observed on illumination by light in the vacuum u.v. range.31... 

Self-Luminescence. The action of UV light or ionizing radiation on pure alkali-metal halide crystals causes intense luminescence particularly at low temperature. The emission spectrum is characteristic for each individual compound. This fluorescence is comparable with the recombination luminescence which occurs upon capture of an electron by a VK center (defect electron). 

Lastly, the action spectra in Ca-HF close to the energy threshold to chemiluminescence display very narrow lines, indicating the partial closure of the corresponding reactive excited-state channel. This indicates that the observed channel luminescence is independent of the ground-state channel that could also contribute to the broadening of the lines in the spectrum and confirms the model of the 4s electron hop separated from the 3d hop. We shall now examine the effect of this hop on the efficiency of production of excited states. 

Chemiluminescence is also shown with a few simple mineral compounds. Otto (21) expressed the opinion that, if ozone causes a luminescence in the presence of water, it acts upon impurities therein. Hydrogen sulfide gives rise to an ultraviolet chemiluminescence with ozone (Zabiezynski and Orlowski, 33). Several oxygen compounds of nitrogen, especially nitric oxide, show, under the action of ozone, a spectrum different from that of active nitrogen [Morren (20), Sarrasin (23), Strutt (26), Knauss and Murrey (17) ]. Solid phosphorus trixode becomes luminescent [Thorpe and Tutton (29)]] and so do carbon monoxide, carbonyl sulfide, and carbonyl chloride at 200 C. The first of these furnishes a band spectrum of 4000 to 5000 A. which corresponds to a bimolecular process [Trautz and Seidel (31) and Trautz and Haller (30)]. Siloxane too shows oxyluminescence [Kautsky and Zocher (16)] under the influence of ozone. 

It is extremely important to elucidate the question of the relationship between the protective action of an additive and its ability for luminescence, as well as the correspondence of its absorption spectrum to the spectrum of the polyamide [91]. Additives of substances differing in their ability to luminesce, as well as possessing different spectra in the ultraviolet region have been used for this purpose [45, 91],... 

---