Boris Rosen

Contribution to the Study of Electronic Spectra of Bent Triatomic Molecules

The electronic absorption spectra of the SO2, SeO2, and TeO2 molecules have been studied under widely varied experimental conditions. The vibrational analysis of the ultraviolet absorption region of SO2 with center of gravity near 2000A reveals that it is formed by at least two electronic systems with the following vibrational constants: System α1···ν0=42,170 cm−1,  ν1′=963 cm−1,  ν2′=379 cm−1,  x′ν2′=2 cm−1.System α2···ν0=44,236 cm−1,  ν1′=775 cm−1,  ν2′=375 cm−1. The presence in the same region of a third electronic system, with ν2′=360 cm−1 and ν1′=845 cm−1, seems highly probable.The character of the vibrational structure of the band systems and a preliminary analysis of the rotational structure of several bands have enabled us to obtain some information about the molecular structure of the excited states.The vibrational analysis of the c‐system of SeO2 in the visible, and the TeO2 bands in the visible and ultraviolet, have enabled us to correlate the electronic states of the three similar molecules.

Recherches sur le spectre d'absorption de la molecule SeO2

Zusammenfassung Das Absorptionsspektrum des SeO2 wurde in 4 m Schichtdicke unter weitgehend variierten Druck- und Temperaturverhaltnissen untersucht. Alle im mittleren ultraviolett befindlichen Banden konnen in ein System eingeordnet werden, welches durch die Formel v=33330+665v´-1.5v´2-900v∳ wiedergegeben wird. In beiden Zustanden wird die einzige beobachtete Frequenz (900 bzw. 665 cm−1) der symmetrischen Valenzschwingung zugeordnet.

Heat of atomization of carbon.

IN a private letter from Princeton dated April 26, 1939, Prof. A. G. Shenstone reported the following observation: “In all cases where I have photographed arcs in N2 using carbon electrodes I have observed three lines which act like C I lines although I have found no trace of them in the literature. They are in the correct position and have proper intervals to be sp3 5S–sp2s 5P. They are quite sharp and I think my measures are probably good to ± 0.01 A.: The suggested identification of Shenstones lines is strongly supported by the iso-electronic comparison, as shown in the accompanying table, and is no doubt correct. The discovery and identification of these carbon lines has reduced—as illustrated by the diagram—the problem of finding the excitation energy (E) of the important 5S-level to the simpler problem of deriving a value (T) of 3s 5P with respect to its parent term, the low 4P of C II. The position of 4P is fixed through inter-system combinations1. From the diagram, in which the figures correspond to the centre of gravity of each multiplet term, one finds E = 64006–T cm.−1.

Recherche sur le spectre moléculaire du sélénium

Abstract The absorption, emission and resonance spectra of Se2 are reinvestigated. Some contradictions existing between the statements of different authors are removed. The main system (probably 3Σ − 3Σ) may be represented by: ν = 26035 − 391,11 u″ + 1,06 u″ − 0,002 u″3 + 281,11 u′ − 2,65 u′3 All the bands of selenium observed in emission and in absorption between 2800 and 5200 A surely belong to this main system. Isotopic effect and perturbations in the upper level of the main system are investigated. Anormal isotopic effects are observed for the perturbed levels. Several questions regarding other band systems attributed to selenium (in particulary the fluting bands in the visible) are discussed.

Étude du spectre du sélénium dans le rouge et l'infrarouge photographique

Summary The band spectra of Se2 were excited in a high frequency electrodeless discharge. The fluting bands on the long wavelength side of the main 1—1 system were investigated in some detail. These bands correspond to transitions between a quasi-stable electronic level situated at about 25000 cm–150 cm−1) and the high excited vibrational levels of the normal state (ω″ = 391 cm−1). The great difference between the frequencies of the two states explains the characteristic structure of this system. A new band system was observed; it can be represented by following formula:v = 16706 + 270 v′ − 2,5 0 − 325 v′2 + v″2; the excited level is the same as that of the main system. The heat of dissociation of Se. is discussed. The value 1,9 V given previously by Rosen and Desirant seems to be the only one, agreeingwith existing spectroscopic data.

Remarques au sujet de la prédissociation observée dans le spectre moléculaire de la vapeur de soufre

Summary Some remarks to recent letters of W. Lochte-Holtgreven and E. Olsson, concerning the predissociation occuring in the band spectrum of S 2 , are made. It seems that the predissociation at v ′ = 10 is a natural one.

Origin of the Broad Bands in Selenium and Tellurium Vapours

IN recent papers, we have investigated a series of broad bands appearing on the long wave-length side of the main system 1∑ − 1∑ of Se2. These bands were observed under electrical1 and optical excitation2,3 as well as in thermoluminescence3.