THERMAL DECOMPOSITION OF MOLECULAR COMPLEXES: I. UREA-n-PARAFFIN INCLUSION COMPOUNDS

1962 ◽  
Vol 40 (12) ◽  
pp. 2195-2203 ◽  
Author(s):  
H. G. McAdie
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Melting Point ◽  
Chain Length ◽  
Inclusion Compounds ◽  
Molecular Complexes ◽  
Enthalpy Change ◽  
Decomposition Process

The molecular complexes of urea and even-numbered n-paraffins up to C28 undergo thermal decomposition below the melting point of urea at temperatures which increase with the n-paraffin chain length. The decomposition is endothermal and is accompanied by changes in crystal structure, appearance, and by loss of the n-paraffin. Based on the enthalpy change a mechanism for the decomposition process is proposed.

THERMAL DECOMPOSITION OF MOLECULAR COMPLEXES: II. β-QUINOL CLATHRATES

1963 ◽  
Vol 41 (9) ◽  
pp. 2137-2143 ◽  
Author(s):  
H. G. McAdie
Keyword(s):  
Carbon Dioxide ◽  
Thermal Decomposition ◽  
Melting Point ◽  
Guest Molecule ◽  
Lattice Distortion ◽  
Molecular Complexes ◽  
Enthalpy Change ◽  
Methyl Cyanide ◽  
Endothermal Effect ◽  
Energy Of Interaction

The β-quinol clathrates of nitrogen, carbon dioxide, methanol, and methyl cyanide decompose at temperatures well below the melting point of the host quinol lattice. The accompanying endothermal effect is broad, indicating that the decomposition occurs gradually over a considerable temperature range. The clathrate decomposition was verified by measurement of the gas evolved. The enthalpy change accompanying decomposition correlates closely with the energy of interaction of the guest molecule with the β-quinol lattice, and the decomposition of the clathrate is suggested to occur by a lattice distortion mechanism in which the size and shape of the guest molecule are important.

scholarly journals THERMAL DECOMPOSITION OF MOLECULAR COMPLEXES: III. UREA INCLUSION COMPOUNDS OF MONOSUBSTITUTED ALIPHATIC SERIES

1963 ◽  
Vol 41 (9) ◽  
pp. 2144-2153 ◽  
Author(s):  
H. G. McAdie
Keyword(s):  
Thermal Decomposition ◽  
Inclusion Compounds ◽  
Guest Molecule ◽  
Molecular Complexes ◽  
Decomposition Temperature ◽  
Urea Inclusion Compounds ◽  
Guest Species ◽  
Alkyl Bromides ◽  
Sufficient Energy ◽  
Urea Inclusion

Examination of the thermal decomposition of urea inclusion compounds has been extended to complexes of the even-numbered members of the following aliphatic series: n-alcohols, n-alkylamines, n-alkyl bromides, and n-carboxylic acids. The decomposition has been studied primarily by differential thermal analysis and an attempt made to correlate the observed decomposition temperatures and heats of decomposition with the particular guest species. The decomposition mechanism appears to involve acquisition of sufficient energy by the guest molecule to permit its diffusion from the canal, the decomposition temperature being related to the activation energy required for this diffusion process.

ChemInform Abstract: BaN3Cl: Synthesis, Crystal Structure, Vibrational Spectra and Thermal Decomposition of Barium Azide Chloride.

ChemInform ◽  
2009 ◽  
Vol 40 (2) ◽  
Author(s):  
Bjoern Blaschkowski ◽  
Harald Balzer ◽  
Hans-Lothar Keller ◽  
Thomas Schleid
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Vibrational Spectra

scholarly journals The crystal structure of the first ether solvate of hexaphenyldistannane [(Ph3Sn)2 • 2 THF]

2020 ◽  
Vol 43 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Jonathan O. Bauer
Keyword(s):  
Crystal Structure ◽  
Inclusion Compounds ◽  
Molecular Crystal ◽  
Structural Features ◽  
Structural Investigations ◽  
Crystal Solvates

AbstractStructural investigations of molecular crystal solvates can provide important information for the targeted crystallization of particular inclusion compounds. Here, the crystal structure of the first ether solvate of hexaphenyldistannane [(Ph3Sn)2 • 2 THF] is reported. Structural features in terms of host-guest interactions and in the context of the previously reported polymorphs and solvates of (Ph3Sn)2 are discussed.

scholarly journals Thermal behavior and decomposition kinetics of rifampicin polymorphs under isothermal and non-isothermal conditions

2010 ◽  
Vol 46 (2) ◽  
pp. 343-351 ◽  
Author(s):  
Ricardo Alves ◽  
Thaís Vitória da Silva Reis ◽  
Luis Carlos Cides da Silva ◽  
Silvia Storpírtis ◽  
Lucildes Pita Mercuri ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Melting Process ◽  
Decomposition Process ◽  
Stable Form ◽  
Thermal Decomposition Process ◽  
Mean Values ◽  
Conversion Level ◽  
Polymorphic Forms ◽  
Crystalline Forms

The thermal behavior of two polymorphic forms of rifampicin was studied by DSC and TG/DTG. The thermoanalytical results clearly showed the differences between the two crystalline forms. Polymorph I was the most thermally stable form, the DSC curve showed no fusion for this species and the thermal decomposition process occurred around 245 ºC. The DSC curve of polymorph II showed two consecutive events, an endothermic event (Tpeak = 193.9 ºC) and one exothermic event (Tpeak = 209.4 ºC), due to a melting process followed by recrystallization, which was attributed to the conversion of form II to form I. Isothermal and non-isothermal thermogravimetric methods were used to determine the kinetic parameters of the thermal decomposition process. For non-isothermal experiments, the activation energy (Ea) was derived from the plot of Log β vs 1/T, yielding values for polymorph form I and II of 154 and 123 kJ mol-1, respectively. In the isothermal experiments, the Ea was obtained from the plot of lnt vs 1/T at a constant conversion level. The mean values found for form I and form II were 137 and 144 kJ mol-1, respectively.

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