Evolved gas analysis of aminophylline and related compounds containing theophylline

Margit Bán, J. Madarász, G. Pokol, Sándor Gál

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

A comparative study on thermal behaviour of a commercial aminophylline (1) and three theophylline (th) compounds containing ethylenediamine (en) analogues, has been carried out by using simultaneous TG/DTA and evolved gas analysis (TG-FTIR). Theophylline ethylenediamine carbamate (2), 1,4-diammoniumbutane bis(theophyllinate) (3) and a physical mixture containing both 1, 6-diaminohexane carbamate and lattice compound of 1,6-diaminohexane with theophylline (4) have been prepared and heated to about 500 °C with 10 °C min-1 rate. The thermal behaviour of the four samples has shown various similarities. Based on simultaneous TG/DTA curves and stoichiometric calculation, it can be seen that all the molecules of the solubilizers are released below 250 °C in flowing air atmosphere. The evolution rate of water of crystallization from aminophylline reaches a maximum at lower temperature than that of ethylenediamine, so water of crystallization leaves easier from the molecular compound. Ethylenediamine carbamate is released as ethylenediamine and carbon dioxide in one TG step from compound 2 as observed by TG-FTIR. The coupled TG-FTIR analysis has also revealed that 1,4-diaminobutane is released without degradation from lattice 3. During the first step of decomposition of 4, the 1,6-diaminohexane carbamate evolved in form of carbon dioxide and diamine. In the second step 1,6-diaminohexane is released from the targeted 1,6-diammoniumhexane bis(theophyllinate). In all cases, in the last step after a slight sublimation, the anhydrous theophylline melts and evaporates totally.

Original languageEnglish
Pages (from-to)587-589
Number of pages3
JournalSolid State Ionics
Volume172
Issue number1-4 SPEC. ISS.
DOIs
Publication statusPublished - Aug 31 2004

Fingerprint

ethylenediamine
1,6-diaminohexane
aminophylline
Aminophylline
Gas fuel analysis
gas analysis
Carbamates
Theophylline
Differential thermal analysis
Carbon dioxide
Crystallization
Sublimation
Carbon Dioxide
Water
carbon dioxide
Decomposition
thermal analysis
Degradation
Molecules
Diamines

Keywords

  • 1,4-Diaminobutane
  • 1,6-Diaminohexane
  • Aminophylline
  • Ethylenediamine
  • TG-FTIR
  • TG/DTA
  • Theophylline

ASJC Scopus subject areas

  • Electrochemistry
  • Physical and Theoretical Chemistry
  • Energy Engineering and Power Technology
  • Materials Chemistry
  • Condensed Matter Physics

Cite this

Evolved gas analysis of aminophylline and related compounds containing theophylline. / Bán, Margit; Madarász, J.; Pokol, G.; Gál, Sándor.

In: Solid State Ionics, Vol. 172, No. 1-4 SPEC. ISS., 31.08.2004, p. 587-589.

Research output: Contribution to journalArticle

Bán, Margit ; Madarász, J. ; Pokol, G. ; Gál, Sándor. / Evolved gas analysis of aminophylline and related compounds containing theophylline. In: Solid State Ionics. 2004 ; Vol. 172, No. 1-4 SPEC. ISS. pp. 587-589.
@article{d474d6cc839a4583bdbb540adde04322,
title = "Evolved gas analysis of aminophylline and related compounds containing theophylline",
abstract = "A comparative study on thermal behaviour of a commercial aminophylline (1) and three theophylline (th) compounds containing ethylenediamine (en) analogues, has been carried out by using simultaneous TG/DTA and evolved gas analysis (TG-FTIR). Theophylline ethylenediamine carbamate (2), 1,4-diammoniumbutane bis(theophyllinate) (3) and a physical mixture containing both 1, 6-diaminohexane carbamate and lattice compound of 1,6-diaminohexane with theophylline (4) have been prepared and heated to about 500 °C with 10 °C min-1 rate. The thermal behaviour of the four samples has shown various similarities. Based on simultaneous TG/DTA curves and stoichiometric calculation, it can be seen that all the molecules of the solubilizers are released below 250 °C in flowing air atmosphere. The evolution rate of water of crystallization from aminophylline reaches a maximum at lower temperature than that of ethylenediamine, so water of crystallization leaves easier from the molecular compound. Ethylenediamine carbamate is released as ethylenediamine and carbon dioxide in one TG step from compound 2 as observed by TG-FTIR. The coupled TG-FTIR analysis has also revealed that 1,4-diaminobutane is released without degradation from lattice 3. During the first step of decomposition of 4, the 1,6-diaminohexane carbamate evolved in form of carbon dioxide and diamine. In the second step 1,6-diaminohexane is released from the targeted 1,6-diammoniumhexane bis(theophyllinate). In all cases, in the last step after a slight sublimation, the anhydrous theophylline melts and evaporates totally.",
keywords = "1,4-Diaminobutane, 1,6-Diaminohexane, Aminophylline, Ethylenediamine, TG-FTIR, TG/DTA, Theophylline",
author = "Margit B{\'a}n and J. Madar{\'a}sz and G. Pokol and S{\'a}ndor G{\'a}l",
year = "2004",
month = "8",
day = "31",
doi = "10.1016/j.ssi.2004.01.063",
language = "English",
volume = "172",
pages = "587--589",
journal = "Solid State Ionics",
issn = "0167-2738",
publisher = "Elsevier",
number = "1-4 SPEC. ISS.",

}

TY - JOUR

T1 - Evolved gas analysis of aminophylline and related compounds containing theophylline

AU - Bán, Margit

AU - Madarász, J.

AU - Pokol, G.

AU - Gál, Sándor

PY - 2004/8/31

Y1 - 2004/8/31

N2 - A comparative study on thermal behaviour of a commercial aminophylline (1) and three theophylline (th) compounds containing ethylenediamine (en) analogues, has been carried out by using simultaneous TG/DTA and evolved gas analysis (TG-FTIR). Theophylline ethylenediamine carbamate (2), 1,4-diammoniumbutane bis(theophyllinate) (3) and a physical mixture containing both 1, 6-diaminohexane carbamate and lattice compound of 1,6-diaminohexane with theophylline (4) have been prepared and heated to about 500 °C with 10 °C min-1 rate. The thermal behaviour of the four samples has shown various similarities. Based on simultaneous TG/DTA curves and stoichiometric calculation, it can be seen that all the molecules of the solubilizers are released below 250 °C in flowing air atmosphere. The evolution rate of water of crystallization from aminophylline reaches a maximum at lower temperature than that of ethylenediamine, so water of crystallization leaves easier from the molecular compound. Ethylenediamine carbamate is released as ethylenediamine and carbon dioxide in one TG step from compound 2 as observed by TG-FTIR. The coupled TG-FTIR analysis has also revealed that 1,4-diaminobutane is released without degradation from lattice 3. During the first step of decomposition of 4, the 1,6-diaminohexane carbamate evolved in form of carbon dioxide and diamine. In the second step 1,6-diaminohexane is released from the targeted 1,6-diammoniumhexane bis(theophyllinate). In all cases, in the last step after a slight sublimation, the anhydrous theophylline melts and evaporates totally.

AB - A comparative study on thermal behaviour of a commercial aminophylline (1) and three theophylline (th) compounds containing ethylenediamine (en) analogues, has been carried out by using simultaneous TG/DTA and evolved gas analysis (TG-FTIR). Theophylline ethylenediamine carbamate (2), 1,4-diammoniumbutane bis(theophyllinate) (3) and a physical mixture containing both 1, 6-diaminohexane carbamate and lattice compound of 1,6-diaminohexane with theophylline (4) have been prepared and heated to about 500 °C with 10 °C min-1 rate. The thermal behaviour of the four samples has shown various similarities. Based on simultaneous TG/DTA curves and stoichiometric calculation, it can be seen that all the molecules of the solubilizers are released below 250 °C in flowing air atmosphere. The evolution rate of water of crystallization from aminophylline reaches a maximum at lower temperature than that of ethylenediamine, so water of crystallization leaves easier from the molecular compound. Ethylenediamine carbamate is released as ethylenediamine and carbon dioxide in one TG step from compound 2 as observed by TG-FTIR. The coupled TG-FTIR analysis has also revealed that 1,4-diaminobutane is released without degradation from lattice 3. During the first step of decomposition of 4, the 1,6-diaminohexane carbamate evolved in form of carbon dioxide and diamine. In the second step 1,6-diaminohexane is released from the targeted 1,6-diammoniumhexane bis(theophyllinate). In all cases, in the last step after a slight sublimation, the anhydrous theophylline melts and evaporates totally.

KW - 1,4-Diaminobutane

KW - 1,6-Diaminohexane

KW - Aminophylline

KW - Ethylenediamine

KW - TG-FTIR

KW - TG/DTA

KW - Theophylline

UR - http://www.scopus.com/inward/record.url?scp=7544242589&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=7544242589&partnerID=8YFLogxK

U2 - 10.1016/j.ssi.2004.01.063

DO - 10.1016/j.ssi.2004.01.063

M3 - Article

VL - 172

SP - 587

EP - 589

JO - Solid State Ionics

JF - Solid State Ionics

SN - 0167-2738

IS - 1-4 SPEC. ISS.

ER -