Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate

The thermal behaviour of zinc(II) acetylsalicylate [Zn(acsa)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] with respect to phase transitions, pyrolysis both in air and inert (N<sub>2</sub>) atmosphere, and product identification has been investigated. The c...

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Autores principales: Lambi, John N., Nsehyuka, Alfred T., Egbewatt, Nkongho, Cafferata, Lázaro F. R., Arvia, Alejandro Jorge
Formato: Articulo
Lenguaje:Inglés
Publicado: 2003
Materias:
Ciencias Exactas
Química
Acetylsalicylate
Pyrolysis
Mesophase
Metathesis
Themogravimetry
Pro-drug
Precursor
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/127494
https://www.sciencedirect.com/science/article/abs/pii/S0040603102003544
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-127494
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Exactas
Química
Acetylsalicylate
Pyrolysis
Mesophase
Metathesis
Themogravimetry
Pro-drug
Precursor
spellingShingle Ciencias Exactas
Química
Acetylsalicylate
Pyrolysis
Mesophase
Metathesis
Themogravimetry
Pro-drug
Precursor
Lambi, John N.
Nsehyuka, Alfred T.
Egbewatt, Nkongho
Cafferata, Lázaro F. R.
Arvia, Alejandro Jorge
Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate
topic_facet Ciencias Exactas
Química
Acetylsalicylate
Pyrolysis
Mesophase
Metathesis
Themogravimetry
Pro-drug
Precursor
description The thermal behaviour of zinc(II) acetylsalicylate [Zn(acsa)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] with respect to phase transitions, pyrolysis both in air and inert (N<sub>2</sub>) atmosphere, and product identification has been investigated. The complex was synthesised by metathesis in hot ethanol solution using aspirin (acetylsalicylic acid) as precursor and characterised via electronic and IR spectral analyses. Optical observations showed that the white salt does not undergo a direct transition from the solid to the liquid phase but rather goes slowly through an intermediate mesophase around 80 °C before melting rapidly to the brick-brown isotropic liquid around 134–136 °C. No liquid crystalline phases are however formed. This result was complemented by that from thermogravimetric (TG) studies in the ca. 25–600 °C range, which showed three main weight-loss phases of 8.0, 50.0 and 14.0% (around 200, 250 and 400 °C) corresponding, respectively, to the elimination of CO<sub>2</sub>, xanthone and acetic acid. The pyrolysis products, as identified using a combination of instrumental (GC–MS) and wet chemical techniques are: CO<sub>2</sub>; non-stoichiometric zinc oxide, most likely in the form: Zn<sub>1+x</sub>O (where 0.0000≤x≤0.0003); and a mixture of organic products resulting from further decomposition, charring and other attendant thermal effects at the relatively high temperatures (ca. 600 °C) involved. Six of the principal organic products were identified and included salsalate and benorylate which are pro-drugs of salicylic acid, a well-known pharmaceutical.
format Articulo
Articulo
author Lambi, John N.
Nsehyuka, Alfred T.
Egbewatt, Nkongho
Cafferata, Lázaro F. R.
Arvia, Alejandro Jorge
author_facet Lambi, John N.
Nsehyuka, Alfred T.
Egbewatt, Nkongho
Cafferata, Lázaro F. R.
Arvia, Alejandro Jorge
author_sort Lambi, John N.
title Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate
title_short Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate
title_full Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate
title_fullStr Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate
title_full_unstemmed Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate
title_sort synthesis, spectral properties and thermal behaviour of zinc(ii) acetylsalicylate
publishDate 2003
url http://sedici.unlp.edu.ar/handle/10915/127494
https://www.sciencedirect.com/science/article/abs/pii/S0040603102003544
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