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- Title
Ammonium carbamate type self-derivative salts of ( R-)- and racemic α-methylbenzylamine.
- Authors
Madarász, János; Székely, Edit; Halász, Judit; Bánsághi, György; Varga, Dániel; Simándi, Béla; Pokol, György
- Abstract
Two different compounds have formed from liquid enantiomeric ( R-) and racemic α-methylbenzylamine (α-MBA, named also as 1-phenylethylamine, 1-FEA) with supercritical fluid CO. The crystalline solids have been characterized by elemental CHN analysis, X-ray diffraction (XRD), FTIR, H, and C NMR spectroscopy, and found to be α-methylbenzylammonium α-methylbenzylcarbamate self-derivative ionic salts 1 ( R/ R) and 2 ( rac RS), respectively, of the corresponding amines. Compound 2 ( rac RS) has shown different XRD pattern from that of enantiomerically pure 1 ( R/ R), indicating a preferential formation of a 1:1 mixture of ( R/ S-) and ( S/ R-) or rather a racemate compound of ( RS/ SR-) ammonium carbamate salt ( 2 ( rac RS)) from racemate. For thermal stability, the compounds have been checked by differential scanning calorimetry (DSC), simultaneous thermogravimetry and differential thermal analysis (TG/DTA), and in situ coupled evolved gas analysis by mass spectroscopy (TG/DTA−EGA−MS) and FTIR-gas cell (TG−FTIR). No melting point is observed because of the low thermal stability of the compounds. Decomposition stages are tried to be separated with using semi-closed (sealed with a pinhole on the top) crucibles, thus different evolution courses of CO and organic vapors could be followed by MS and FTIR spectroscopy. The α-MBA vapors themselves, evolved from open crucibles could be identified by FTIR-gas cell, while vapors up to m/ z = 164 have been detected by MS from semi-closed Al crucible.
- Subjects
AMMONIUM compounds; CARBAMATES; CHEMICAL derivatives; SALT; BENZYLAMINE; FOURIER transform infrared spectroscopy; DIFFERENTIAL scanning calorimetry
- Publication
Journal of Thermal Analysis & Calorimetry, 2013, Vol 111, Issue 1, p567
- ISSN
1388-6150
- Publication type
Article
- DOI
10.1007/s10973-011-2174-5