Ammonium carbamate type self-derivative salts of (R-)- and racemic α-methylbenzylamine

Composition and thermal stability by evolved gas analyses (TG-FTIR and TG/DTA-MS)

J. Madarász, Edit Székely, Judit Halász, György Bánsághi, Dániel Varga, B. Simándi, G. Pokol

Research output: Contribution to journalArticle

7 Citations (Scopus)

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 CO2. The crystalline solids have been characterized by elemental CHN analysis, X-ray diffraction (XRD), FTIR, 1H, and 13C 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 CO2 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.

Original languageEnglish
Pages (from-to)567-574
Number of pages8
JournalJournal of Thermal Analysis and Calorimetry
Volume111
Issue number1
DOIs
Publication statusPublished - Jan 2013

Fingerprint

thermogravimetry
Differential thermal analysis
Thermogravimetric analysis
Crucibles
thermal analysis
Thermodynamic stability
crucibles
thermal stability
Salts
Gases
salts
Derivatives
Vapors
vapors
Chemical analysis
gases
Spectroscopy
Phenethylamines
X ray diffraction
Gas fuel analysis

Keywords

  • Differential scanning calorimetry (DSC)
  • Evolved gas analysis (EGA)
  • FTIR spectroscopy
  • Mass spectrometry (MS)
  • Simultaneous TG/DTA
  • TG-FTIR
  • TG/DTA-MS
  • X-ray diffraction (XRD)

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Condensed Matter Physics

Cite this

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title = "Ammonium carbamate type self-derivative salts of (R-)- and racemic α-methylbenzylamine: Composition and thermal stability by evolved gas analyses (TG-FTIR and TG/DTA-MS)",
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 CO2. The crystalline solids have been characterized by elemental CHN analysis, X-ray diffraction (XRD), FTIR, 1H, and 13C 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 CO2 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.",
keywords = "Differential scanning calorimetry (DSC), Evolved gas analysis (EGA), FTIR spectroscopy, Mass spectrometry (MS), Simultaneous TG/DTA, TG-FTIR, TG/DTA-MS, X-ray diffraction (XRD)",
author = "J. Madar{\'a}sz and Edit Sz{\'e}kely and Judit Hal{\'a}sz and Gy{\"o}rgy B{\'a}ns{\'a}ghi and D{\'a}niel Varga and B. Sim{\'a}ndi and G. Pokol",
year = "2013",
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TY - JOUR

T1 - Ammonium carbamate type self-derivative salts of (R-)- and racemic α-methylbenzylamine

T2 - Composition and thermal stability by evolved gas analyses (TG-FTIR and TG/DTA-MS)

AU - Madarász, J.

AU - Székely, Edit

AU - Halász, Judit

AU - Bánsághi, György

AU - Varga, Dániel

AU - Simándi, B.

AU - Pokol, G.

PY - 2013/1

Y1 - 2013/1

N2 - 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 CO2. The crystalline solids have been characterized by elemental CHN analysis, X-ray diffraction (XRD), FTIR, 1H, and 13C 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 CO2 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.

AB - 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 CO2. The crystalline solids have been characterized by elemental CHN analysis, X-ray diffraction (XRD), FTIR, 1H, and 13C 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 CO2 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.

KW - Differential scanning calorimetry (DSC)

KW - Evolved gas analysis (EGA)

KW - FTIR spectroscopy

KW - Mass spectrometry (MS)

KW - Simultaneous TG/DTA

KW - TG-FTIR

KW - TG/DTA-MS

KW - X-ray diffraction (XRD)

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U2 - 10.1007/s10973-011-2174-5

DO - 10.1007/s10973-011-2174-5

M3 - Article

VL - 111

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EP - 574

JO - Journal of Thermal Analysis and Calorimetry

JF - Journal of Thermal Analysis and Calorimetry

SN - 1388-6150

IS - 1

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