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  • Author or Editor: Regina C. G. Frem x
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Abstract

This work reports the synthesis, characterization, and thermal behavior of three complexes of copper (II): [CuCl2(HPz)4] (1), [CuCl2(HdmPz)4] (2), and [CuCl2(HIPz)4] (3) (HPz = pyrazole; HdmPz = 3,5-dimethylpyrazole; HIPz = 4-iodopyrazole). The compounds were characterized by elemental analysis, infrared spectroscopy, and UV–Vis measurements. The thermal study of the compounds showed that the ligands are eliminated in 2–4 stages, yielding CuO as final residue.

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Journal of Thermal Analysis and Calorimetry
Authors: Sahra C. Lemos, Silmar J. S. Franchi, Adelino V. G. Netto, Antonio E. Mauro, Oswaldo Treu-Filho, Regina C. G. Frem, Eduardo Tonon de Almeida, and Cláudia Torres

Abstract

This work describes the synthesis, characterization, and the thermal behavior investigation of four palladium(II) complexes with general formulae [PdX2(mba)2], in which mba = N-methylbenzylamine and X = OAc (1), Cl (2), Br (3) or I (4). The complexes were characterized by elemental analysis, infrared vibrational spectroscopy, and 1H nuclear magnetic resonance. The stoichiometry of the complexes was established by means of elemental analysis and thermogravimetry (TG). TG/DTA curves showed that the thermodecomposition of the four complexes occurred in 3–4 steps, leading to metallic palladium as final residue. The palladium content found in all curves was in agreement with the mass percentages calculated for the complexes. The following thermal stability sequence was found: 3 > 2 > 4 > 1. The geometry optimization of 1, 2, 3, and 4, calculated using the DFT/B3LYP method, yielded a slightly distorted square planar environment around the Pd(II) ion made by two anionic groups and two nitrogen atoms from the mba ligand (N1 and N2), in a trans-relationship.

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Journal of Thermal Analysis and Calorimetry
Authors: A. V. G. Netto, A. M. Santana, A. E. Mauro, Regina C. G. Frem, E. T. de Almeida, M. S. Crespi, and H. E. Zorel Jr.
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New palladium(II) complexes with pyrazole ligands

Part I. Synthesis, spectral and thermal studies, and antitumor evaluation

Journal of Thermal Analysis and Calorimetry
Authors: Carolina V. Barra, Fillipe V. Rocha, Adelino V. G. Netto, B. Shimura, Regina C. G. Frem, Antonio E. Mauro, Iracilda Z. Carlos, Sandra R. Ananias, and Marcela B. Quilles

Abstract

The pyrazole ligand 3,5-dimethyl-4-iodopyrazole (HdmIPz) has been used to obtain a series of palladium(II) complexes (14) of the type [PdX2(HdmIPz)2] {X = Cl (1); Br (2); I (3); SCN (4)}. All compounds have been isolated, purified, and characterized by means of elemental analysis, IR spectroscopy, 1H and 13C{1H}-NMR experiments, differential thermal analysis (DTA), and thermogravimetry (TG). The TG/DTA curves showed that the compounds released ligands in the temperature range 137–605 °C, yielding metallic palladium as final residue. The complexes and the ligand together with cisplatin have been tested in vitro by MTT assay for their cytotoxicity against two murine cancer cell lines: mammary adenocarcinoma (LM3) and lung adenocarcinoma (LP07).

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Journal of Thermal Analysis and Calorimetry
Authors: Fillipe V. Rocha, Carolina V. Barra, Silmar J. S. Franchi, Adelino V. G. Netto, Antonio E. Mauro, and Regina C. G. Frem

Abstract

Four new mononuclear Pd(II) complexes of the type [PdX2(tdmPz)] {X = Cl (1); Br (2); I (3); SCN (4); tdmPz = 1-thiocarbamoyl-3,5-dimethylpyrazole} have been synthesized and characterized by elemental analysis, IR spectroscopy, 1H and 13C{1H}-NMR experiments. The thermal behavior of the complexes 14 has been investigated by means of thermogravimetry (TG) and differential thermal analysis (DTA). From the initial decomposition temperatures, the thermal stability of the complexes can be ordered in the sequence: 3 < 4 2 < 1. The final products of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.

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New palladium(II) complexes with pyrazole ligands

Part II. Synthesis, spectral and thermal studies, and antitumor evaluation

Journal of Thermal Analysis and Calorimetry
Authors: Carolina V. Barra, Fillipe V. Rocha, Adelino V. G. Netto, Regina C. G. Frem, Antonio E. Mauro, Iracilda Z. Carlos, Sandra R. Ananias, and Marcela B. Quilles

Abstract

This study describes the synthesis, IR, 1H, and 13C{1H} NMR spectroscopic as well the thermal characterization of the new palladium(II) pyrazolyl complexes [PdCl2(HmPz)2] 1, [PdBr2(HmPz)2] 2, [PdI2(HmPz)2] 3, [Pd(SCN)2(HmPz)2] 4 {HmPz = 4-methylpyrazole}. The residues of the thermal decomposition were identified as Pd0 by X-ray powder diffraction. From the initial decomposition temperatures, the thermal stability of the complexes can be ordered in the sequence: 1 > 2 > 43. The cytotoxic activities of the complexes and the ligand were investigated against two murine cancer cell lines: mammary adenocarcinoma (LM3) and lung adenocarcinoma (LP07) and compared to cisplatin under the same experimental conditions.

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