Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicos
By using thermochemical data reported for a series of chelates of the type [Ln(thd)3], thd = 2, 2, 6, 6 tetramethyl- 3,5-heptanedione and Ln = La, Pr, Nd, Sm, Gd, Tb, Ho, Er, Tm and Yb, empirical correlations were found involving thermochemical parameters (e.g. dissociation enthalpy) and the therm...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Química
2000-01-01
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| Series: | Química Nova |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422000000500002 |
| _version_ | 1811343737302810624 |
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| author | Farias Robson Fernandes de |
| author_facet | Farias Robson Fernandes de |
| author_sort | Farias Robson Fernandes de |
| collection | DOAJ |
| description | By using thermochemical data reported for a series of chelates of the type [Ln(thd)3], thd = 2, 2, 6, 6 tetramethyl- 3,5-heptanedione and Ln = La, Pr, Nd, Sm, Gd, Tb, Ho, Er, Tm and Yb, empirical correlations were found involving thermochemical parameters (e.g. dissociation enthalpy) and the thermodynamic temperatures of the beginning of thermal degradation of the chelates, t i. It is shown that t i values are of capital importance in the study of this all class of coordination compounds. Among others, the empirical equation is obtained: r3+ = (-0,013.Z + 1,36)/0,005, that relates the lanthanide cation radius (pm) with the atomic number of the element. The remarkable fact is that this equation is achieved by using thermogravimetric and calorimetric parameters. Is also shown that t i values are related with the P(M) function values, which are very close related with the energy difference, deltaE, between the lowest electronic energy level of the f n s²d¹ configuration and the lowest energy level of the f n+1s² configuration in the neutral gaseous atoms. |
| first_indexed | 2024-04-13T19:35:10Z |
| format | Article |
| id | doaj.art-1e7d8de5a1234c20a3bf6186addae8bf |
| institution | Directory Open Access Journal |
| issn | 0100-4042 1678-7064 |
| language | English |
| last_indexed | 2024-04-13T19:35:10Z |
| publishDate | 2000-01-01 |
| publisher | Sociedade Brasileira de Química |
| record_format | Article |
| series | Química Nova |
| spelling | doaj.art-1e7d8de5a1234c20a3bf6186addae8bf2022-12-22T02:33:03ZengSociedade Brasileira de QuímicaQuímica Nova0100-40421678-70642000-01-01235581584Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicosFarias Robson Fernandes deBy using thermochemical data reported for a series of chelates of the type [Ln(thd)3], thd = 2, 2, 6, 6 tetramethyl- 3,5-heptanedione and Ln = La, Pr, Nd, Sm, Gd, Tb, Ho, Er, Tm and Yb, empirical correlations were found involving thermochemical parameters (e.g. dissociation enthalpy) and the thermodynamic temperatures of the beginning of thermal degradation of the chelates, t i. It is shown that t i values are of capital importance in the study of this all class of coordination compounds. Among others, the empirical equation is obtained: r3+ = (-0,013.Z + 1,36)/0,005, that relates the lanthanide cation radius (pm) with the atomic number of the element. The remarkable fact is that this equation is achieved by using thermogravimetric and calorimetric parameters. Is also shown that t i values are related with the P(M) function values, which are very close related with the energy difference, deltaE, between the lowest electronic energy level of the f n s²d¹ configuration and the lowest energy level of the f n+1s² configuration in the neutral gaseous atoms.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422000000500002lanthanidesthermochemistrythermogravimetryempirical correlations |
| spellingShingle | Farias Robson Fernandes de Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicos Química Nova lanthanides thermochemistry thermogravimetry empirical correlations |
| title | Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicos |
| title_full | Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicos |
| title_fullStr | Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicos |
| title_full_unstemmed | Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicos |
| title_short | Sobre a aplicabilidade da termogravimetria para a estimativa de parâmetros termoquímicos de compostos de coordenação: os elementos lantanídicos |
| title_sort | sobre a aplicabilidade da termogravimetria para a estimativa de parametros termoquimicos de compostos de coordenacao os elementos lantanidicos |
| topic | lanthanides thermochemistry thermogravimetry empirical correlations |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422000000500002 |
| work_keys_str_mv | AT fariasrobsonfernandesde sobreaaplicabilidadedatermogravimetriaparaaestimativadeparametrostermoquimicosdecompostosdecoordenacaooselementoslantanidicos |