The 240 nm band system of methylamine: a preliminary analysis of the rotational structure of the 0–0 band of CH3ND2

1982 ◽  
Vol 60 (6) ◽  
pp. 844-854 ◽  
Author(s):  
Masamichi Tsuboi ◽  
Akiko Y. Hirakawa

The ultraviolet absorption spectrum of CH3ND2 has been observed in the 231–242 nm (43 300–41 300 cm−1) region with 10 m Eagle and 7.3 m Ebert vacuum spectrographs. An analysis has been made of the rotational structure in the 238.1–236.7 nm (42 000–42 240 cm−1) region. It has been shown that, in the excited electronic state, the methyl group is rotating freely with respect to the amino group around the C—N bond as axis. Here the moment of inertia of the methyl group was found to be 3.4054 Å2 amu around the molecular axis, and that of the deuterated amino group ND2 3.4081 Å2 amu. The sum 6.8135 Å2 amu is appreciably greater than IA = 6.6280 Å2 amu, the moment of inertia for the overall rotation of the molecule.

1967 ◽  
Vol 45 (7) ◽  
pp. 2355-2374 ◽  
Author(s):  
C. Weldon Mathews

The absorption spectrum of CF2 in the 2 500 Å region has been photographed at high dispersion, and the rotational structure of a number of bands has been analyzed. The analysis of the well-resolved subbands establishes that these are perpendicular- rather than parallel-type bands, as previously assigned. Further analysis shows that the upper and lower electronic states are of 1B1 and 1A1symmetries respectively, corresponding to a transition moment that is perpendicular to the plane of the molecule. In the upper electronic state, r0(CF) = 1.32 Å and [Formula: see text], while in the ground state, r0(CF) = 1.300 Å and [Formula: see text]. An investigation of the vibrational structure of the band system has shown that the vibrational numbering in ν2′ must be increased by one unit from earlier assignments, thus placing the 000–000 band near 2 687 Å (37 220 cm−1). A search between 1 300 and 8 500 Å showed two new band systems near 1 350 and 1 500 Å which have been assigned tentatively to the CF2 molecule.


1953 ◽  
Vol 31 (10) ◽  
pp. 952-957 ◽  
Author(s):  
Barry P. Moore ◽  
Léo Marion

The alkaloid hitherto described as obscurine has been shown to consist of a mixture of two bases, α-obscurine (C17H26ON2) and β-obscurine (C17H24ON2). Dehydregenation of α-obscurine by heating with palladium-charcoal gives rise to 7-methylquinoline and 6-methyl-α-pyridone. The infrared absorption spectrum of the base shows absorption bands indicative of a carbony and of a secondary amino group, possibly in a cyclic lactam, while absorption in the ultraviolet indicates the presence of a double bond conjugated with the carbonyl group. β-Obscurine on the other hand contains an α-pyridone ring as shown by its infrared absorption spectrum and also by the similarity of its ultraviolet absorption spectrum with that of 6-methyl-α-pyridone.


1982 ◽  
Author(s):  
Carol Zahner ◽  
M. Stephen Kaminaka

Author(s):  
Chuanwen Zhang ◽  
Guangxu Zhou ◽  
Ting Yang ◽  
Ningran Song ◽  
Xinli Wang ◽  
...  

1971 ◽  
Vol 34 (4) ◽  
pp. 255-256 ◽  
Author(s):  
S.A. Hjorth ◽  
J. Oppelstrup ◽  
G. Ehrling

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