Ultraviolet Absorption Spectra of Alkali Metal Azides

1961 ◽  
Vol 35 (6) ◽  
pp. 2122-2127 ◽  
Author(s):  
S. K. Deb
1964 ◽  
Vol 42 (6) ◽  
pp. 1255-1260 ◽  
Author(s):  
S. Bywater ◽  
A. F. Johnson ◽  
D. J. Worsfold

The ultraviolet absorption spectra of living anionic polymerizing systems have been measured with sytrene, butadiene, and isoprene as the monomers; with lithium, sodium, and potassium as the alkali metals; and with tetrahydrofuran, cyclohexane, and benzene as the solvents. For any monomer the similarity of the spectra obtained with the various metals and solvents leads to the conclusion that the alkali metal – carbon band has the same structure under the various conditions. From other evidence the bond is considered to be ionic in all cases. The diene monomer anions in tetrahydrofuran solution were found to undergo a series of isomerizations, some of them comparable in speed to the consumption of monomer.


1981 ◽  
Vol 46 (7) ◽  
pp. 1600-1606 ◽  
Author(s):  
Jan Bartoň ◽  
Karel Volka ◽  
Miroslav Kašpar ◽  
Vlastimil Růžička

The mechanism of controlled anionic coordination dimerization of isoprene (i.e. 2-methyl-1,3-butadiene) in the system tetrahydrofuran-isoprene-alkali metal-dialkylamine was investigated by using absorption spectrophotometry in the range of visible radiation and gas chromatography. The effect of the alkali metal (Li, Na, K) and dialkylamine (dicyclohexylamine, N-isopropylcyclohexylamine, N-methylisopropylamine) on the absorption spectra was tested. By comparing chromatographic and spectrophotometric data, the absorption bands in the range of visible radiation were identified with the existence of π-complexes between oligomeric forms of isoprene and alkali metal dialkylamide.


2013 ◽  
Vol 779 (1) ◽  
pp. 40 ◽  
Author(s):  
Yu-Jong Wu ◽  
Hui-Fen Chen ◽  
Shiang-Jiun Chuang ◽  
Tzu-Ping Huang

1950 ◽  
Vol 187 (1) ◽  
pp. 299-312
Author(s):  
R.L. Sinsheimer ◽  
J.F. Scott ◽  
J.R. Loofbourow

1959 ◽  
Vol 37 (3) ◽  
pp. 563-574 ◽  
Author(s):  
Eugene Lieber ◽  
J. Ramachandran ◽  
C. N. R. Rao ◽  
C. N. Pillai

The ultraviolet absorption spectra of 5-(substituted)amino-1,2,3,4-thiatriazoles and the corresponding isomeric 1-substituted-tetrazoline-5-thiones have been studied. The spectra and the dipole moments of the 5-(substituted)amino-1,2,3,4-thiatriazoles eliminate the possibility of meso-ionic structures for these compounds. The dipole moments of 5-amino-, 5-methylamino-, and 5-dimethylamino-1,2,3,4-thiatriazole were all high but approximately of the same value (5.77 to 5.84 D). This suggests that the amino thiatriazoles are best represented by conventional covalent structures with significant ionic resonance contributions. The thiatriazole ring system exhibits a characteristic absorption maximum at 250–255 mμ and an electron-withdrawing effect approximately equal to the tetrazolyl ring system. The tetrazolinethionolyl ring system is similarly electron-withdrawing. The relative acidities of the 1-substituted-tetrazoline-5-thiones and the 5-alkylmercaptotetrazoles have also been studied and the results support the observations made on the basis of their ultraviolet absorption spectra.


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