The halide-bridge cleavage reaction of the [Pd(C2 ,N-bzox)(µ-Cl)]2 compound (bzox = benzaldehydeoxime) with ethylenethiourea (L) in the 1:2 molar ratio at room temperature yielded the cyclopalladated compound [Pd(C2 ,N-bzox)(Cl)(L)] (1) whose replacement of the halide group by the addition of suitable salts afforded compounds of general formulae [Pd(C2 ,N-bzox)(X)(L)] {X = Br- (2), I- (3)}. All compounds were characterized by melting point, elemental analyses, infrared and 1H- and 13C{1H}-NMR spectroscopies revealing the complexes formation with the oxime coordinated to Pd(II) as C,N-chelating and the ethylenethiourea as a monodentate ligand via the sulfur atom. The cytotoxicity of cyclopalladated compounds has been evaluated in vitro against murine mammary tumor cell (LM3) showing cytotoxic activity similar to cisplatin.

The present study describes the antiprotozoal activities of four cyclopalladated compounds, [Pd(dmba)(μ-Cl)]2, [Pd(dmba)(NCO)(isn)], [Pd(dmba)(N3)(isn)] and [Pd(dmba)(μ-NCO)]2, (dmba: N,N'-dimethylbenzylamine and isn: isonicotinamide), against the diseases leishmaniasis (Leishmania amazonensis and Leishmania infantum), Chagas disease (Trypanosoma cruzi) and human African trypanosomiasis (Trypanosoma brucei). [Pd(dmba)(μ-NCO)]2 exhibited good leishmanicidal and trypanocidal activities against L. amazonensis and T. cruzi intracellular amastigote forms, with a 50% inhibitory concentration (IC50) value of less than 9 µM and selectivity indexes of 14.47 and 28.42, respectively. Stability essays were conducted in phosphate buffer saline (PBS) pH 7.0 and showed that [Pd(dmba)(μ-NCO)]2 is the most stable molecule. These findings indicate that this compound presented higher selectivity for these parasites than the other tested compounds. The data presented here suggest that this compound should be considered in the development of new and more potent drugs for the treatment of leishmaniasis and Chagas disease.

Os complexos polinucleares [{PdCl2(µ-Htrz)}n] (1) e [{PdBr2(µ-Htrz)}n] (2) (Htrz = 1,2,4-triazol) foram sintetizados neste trabalho. O composto 1 foi preparado a partir da substituição da acetonitrila do precursor [PdCl2(MeCN)2] pelo 1,2,4-triazol. A adição posterior de brometo de potássio ao meio reacional resultou na formação do complexo 2. Os complexos inéditos foram isolados, purificados e caracterizados por análise elementar, espectroscopias vibracional no infravermelho e eletrônica no UV-visível e curvas de análise termogravimétrica (TG). Os resultados experimentais sugerem que, em ambos os casos, a coordenação do 1,2,4-Htrz ocorra via átomos N(2) e N(4), atuando como pontes entre centros de paládio. O poliedro de coordenação quadrado-planar ao redor do paládio(II) é determinado pelos dois átomos de N do heterociclo e por dois ligantes cloro (1) ou bromo (2), em uma provável configuração trans. As curvas TG indicaram que a natureza do ligante aniônico não afeta significativamente a estabilidade térmica de 1 e 2. Os produtos finais de decomposição térmica foram identificados como paládio metálico pela técnica de difratometria de raios X de pó. Testes preliminares envolvendo a avaliação dos efeitos dos compostos 1, 2 e Htrz na produção de H2O2 e NO em culturas de macrófagos peritoneais de camundongos BALB/c foram realizados in vitro.

The 1,2,4-triazolyl-bridged polynuclear complexes [{PdCl2(µ-Htrz)}n] (1) and [{PdBr2(µ-Htrz)}n] (2) have been obtained in this work. Compound 1 is prepared by the displacement of acetonitrile from [PdCl2(MeCN)2] by 1,2,4-triazole (Htrz). Further addition of potassium bromide to the reaction medium afforded complex 2. The new complexes have been isolated, purified and characterized by means of elemental analysis, IR and UV-visible electronic spectroscopies and thermogravimetric (TG) curves. The experimental data suggested that, in both cases, the coordination of 1,2,4-Htrz takes place through the N(2) and N(4) atoms, bridging the palladium centers. The square-planar coordination polyhedron of palladium(II) is determined by two nitrogen atoms from the triazole ligands, while the other two coordination positions are occupied by the chloro (1) or bromo (2) ligands. TG curves indicated that the nature of the anionic ligand does not affect significantly the thermal stability of 1 and 2. The final products of the thermal decompositions were identified as metallic palladium by X-ray powder diffractometry. Preliminary tests involving the evaluation of the effects of compounds 1, 2 and Htrz on H2O2 and NO production in cultures of peritoneal macrophages from BALB/c mice were carried out in vitro.

Os ciclometalados de paládio(II) são compostos inorgânicos reativos empregados em vários estudos biológicos devido a seu potencial antitumoral e interação com o sistema imune. Neste estudo, a resposta imune e citotóxica induzida por dois complexos organopaladados: [{Pd(N,C-dmba)}2(µ-NCS)2 ] (1), [Pd(C-dmba)(NCS)(dppp)] (2) [dmba = N,N'dimetilbenzilamina, dppp = 1,3-bis(difenilfosfino)propano] e cisplatina (cis-DDP), como padrão, foram investigados em camundongos portadores do tumor ascítico de Ehrlich. Os camundongos foram divididos em cinco grupos e inoculados com (1) ou (2) ou cis-DDP ou apenas veículo ou solução salina tamponada de fosfatos (PBS). Diversos parâmetros foram avaliados, tais como a porcentagem de células tumorais presentes no exsudato peritoneal, os níveis de óxido nítrico (NO) e fator de necrose tumoral (TNF-alfa) séricos e o aumento na expectativa de vida. Os dados obtidos demonstram que o composto (2) apresentou atividade similar à da cis-DDP, como, por exemplo, aumento na expectativa de vida, diminuição dos níveis séricos de TNF-alfa e aumento da produção de NO.

Cyclometallated palladium(II) complexes are reactive inorganic compounds employed in several biological studies because of their antitumour potential and interaction with immune system. In the present study, the immune and citotoxic response induced by two organopalladated complexes: [{Pd(N,C-dmba)}2(µ-NCS)2 ] (1), [Pd(C-dmba)(NCS)(dppp)] (2) [dmba = N,N'dimethylbenzylamine, dppp = 1,3-bis(diphenylphosphino)propane] and cisplatin (cis-DDP), as standard, were investigated in mice bearing Ehrlich ascites tumour. The mice were divided into five groups and inoculated with the compounds (1) or (2) or cisplatin, or only vehicle or phosphate-buffered saline (PBS). Many parameters were evaluated, such as tumour cell percentage in the peritoneal exsudate, levels of seric nitric oxide (NO) and tumour necrosis factor-alpha (TNF-alpha) and increase in life span. Analysis of all data revealed, for compound (2), an activity similar to that presented by cisplatin, resulting in increased life span, lower levels of seric TNF-alpha and increase in NO production.

A reação entre Cu(NO3)2.3H2O e 1,3-propanodiamina (pn), na presença de NaN3, conduziu à obtenção de um co-cristal 1:1 formado por [Cu(NO3)2(pn)2] e [Cu(N3)(NO3)(pn)2] (1 e 2), os quais foram caracterizados por análise elementar, espectroscopia no IV e difração de raios X por monocristal. Em ambos os compostos, os átomos de cobre(II) encontram-se em um ambiente octaédrico distorcido, com quatro ligações no plano basal formadas por quatro átomos de N de dois ligantes pn bidentados enquanto que as ligações axiais são formadas por dois átomos de O do ligante nitrato em 1 e por um átomo de O do ligante nitrato e um átomo de N do íon azida em 2. A estrutura cristalina consiste em dois complexos (1 e 2) cristalograficamente independentes, que se unem por uma série de ligações de hidrogênio do tipo N-H···O e N-H···N bem como interações por C-H···O. Novos synthons supramoleculares foram identificados pela ocorrência de dois modos geometricamente distintos de reconhecimento molecular envolvendo o íon NO3- e grupos amino dos ligantes pn.

The reaction of Cu(NO3)2.3H2O with 1,3-propanediamine (pn), in the presence of NaN3, afforded a 1:1 co-crystal formed by [Cu(NO3)2(pn)2] and [Cu(N3)(NO3)(pn)2 ] (1 and 2), which were characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. In both compounds, the copper(II) centers are in a distorted octahedral environment, formed by four N atoms of two bidentate pn ligands in the basal plane, whereas the axial bonds are formed by two O atoms from the nitrate ligands in 1 and one O atom from the nitrate ligand and one N atom from the azide ion in 2. The asymmetric unit of the crystal consists of two crystallographically independent 1 and 2 complexes, which are held together in a 3D network by a series of N-H···O and N-H···N hydrogen bonds, as well C-H···O interactions. New supramolecular synthons are identified by the occurrence of two geometrically distinct molecular recognition patterns involving the NO3- ion and amino groups from pn ligands.

As reações do ciclopaladado catiônico [Pd(N,C-dmba)(MeCN)2](NO3) (1) (dmba = N,N-dimetilbenzilamina), como os pré-ligantes 3,5-dimetilpirazol (Hdmpz); 2-quinolinatiol (qnSH) e 1,1'-bis(difenilfosfina)ferroceno (dppf) levaram à formação dos compostos, respectivamente, [Pd(N,C-dmba)(Hdmpz)(ONO2)]0.5CH2 Cl2 (2), [Pd(N,C-dmba)(qnSH)(ONO2)] 0.5CH2Cl2 (3) e [Pd(N,C-dmba)(dppf)](NO3) (4). As novas espécies mononucleares 2, 3 e 4 foram caracterizadas através de análise elementar, espectroscopia de absorção na região do infravermelho, espectroscopia de ressonância magnética nuclear e análise termogravimétrica. Os dados da espectroscopia no IV mostram bandas consistentes com o grupo nitrato monodentado nos casos dos compostos 2 e 3 e nitrato iônico no da espécie 4. Os dados de RMN de 13C e ¹H confirmam que os respectivos ligantes encontram-se coordenados ao átomo de paládio e o RMN de 31P{¹H} de 4 evidencia claramente a ocorrência de três espécies ciclopaladadas em solução, com o dppf atuando como ligante ponte em duas e como um quelato em uma. O comportamento térmico dos compostos 1-4 sugere que o composto 2 é o mais estável. Os resultados da difratometria de raios X, método do pó, confirmam a formação dos seguintes resíduos finais de termodecomposição: PdO para as espécies 1 e 2, uma mistura de PdO e Fe2(PO4)3 para 4 e, Pd2OSO4 para o composto 3.

The reactions of the precursor [Pd(N,C-dmba)(MeCN)2](NO3) (1) (dmba = N,N-dimethylbenzylamine), with the proligands 3,5-dimethylpyrazole (Hdmpz), 2-quinolinethiol (qnSH) and 1,1'-bis(diphenylphosphine)ferrocene (dppf) afforded the compounds [Pd(N,C-dmba)(Hdmpz)(ONO2)]0.5CH2 Cl2 (2), [Pd(N,C-dmba)(qnSH)(ONO2)] 0.5CH2Cl2 (3) and [Pd(N,C-dmba)(dppf)](NO3) (4), respectively. The mononuclear species 2, 3 and 4 were characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric analysis. The IR spectra show bands which are consistent with terminal monodentate nitrate group for 2-3 and ionic nitrate for 4. The ¹H and 13C NMR data confirm that coordination of the organic ligands has occurred and the 31P{¹H} NMR data for 4 clearly evidences the occurrence in solution of three cyclopalladated species with the dppf acting as a bridging ligand in two cases and as a chelate in one. The thermal behavior of compounds 1-4 suggests that complex 2 is the most stable. The X-ray diffractometry results show the formation of PdO from 1 and 2, Pd2OSO4 from 3, and of a mixture of PdO and Fe2(PO4)3 from 4, as final decomposition products.

Tetrahydroborate complexes of copper (I) with bidentate phosphines, [Cu(eta²-BH4)(dppm)] (1), [Cu(eta²-BH4)(dppe)] (2), [Cu(eta²-BH4)(cis-dppet)] (3) and [Cu(eta²-BH4)(dppb)] (4) (dppm = bis(diphenylphosphino)methane; dppe = 1,2-bis(diphenylphosphino) ethane; cis-dppet = 1,2-cis(diphenylphosphino)ethene; dppb = 1,4-bis(diphenylphosphino)butane) were prepared and characterized by elemental analysis, infrared spectroscopy, NMR and thermogravimetric analysis. The IR data for 1-4 showed bands typical of a bidentate coordination of BH4 group to the copper atom and the 31P{¹H} NMR spectra indicated that the phosphorous atoms are chelating the metal centre. The thermal behavior of the compounds was investigated and suggested that their thermal stability is influenced by the phosphines. Their thermal stability decreased as follows: [Cu(eta²-BH4)(dppe)] (2) > [Cu(eta²-BH4)(dppm)] (1) > [Cu(eta²-BH4)(dppb)] (4) > [Cu(eta²-BH4)(cis-dppet)] (3). According to thermal analysis and X-ray diffraction patterns all compounds decomposed giving Cu(BO2)2, CuO, CuO2 and Cu as final products.

Este trabalho tratou da síntese, caracterização espectroscópica e do comportamento eletroquímico dos compostos [W(CO)4(bipy)] (1), [W(CO)3(bipy)(dppm)] (2) e [W(CO)3(bipy)(dppf)] (3), bipy = 2,2'-bipiridina; dppm = bis(difenilfosfina)metano; dppf = 1,1'-bis(difenilfosfina)ferroceno. Os dados provenientes das espectroscopias no infravermelho e de RMN 31P{¹H} mostraram que o tungstênio apresenta uma geometria de coordenação octaédrica com as fosfinas atuando como ligantes monodentados. Os estudos eletroquímicos foram realizados empregando-se as técnicas de voltametria cíclica e coulometria a potencial controlado. Os voltamogramas cíclicos mostraram que os carbonil complexos contendo ligantes fosforados apresentam uma maior estabilidade frente à oxidação do que o composto (1).

The present work deals with the synthesis, spectroscopic investigation and electrochemical behaviour of the compounds [W(CO)4(bipy)] (1), [W(CO)3(bipy)(dppm)] (2) and [W(CO)3(bipy)(dppf)] (3), bipy = 2,2'-bipyridine; dppm = bis(diphenylphosphino)methane; dppf = 1,1'-bis(diphenylphosphino)ferrocene. The IR and 31P{¹H} NMR spectroscopic data have shown an octahedral coordination geometry for the tungsten atom with the diphosphines acting as monodentate ligands. The electrochemical behaviour of the complexes was investigated by cyclic voltammetry and controlled potential coulometry. Cyclic voltammograms have indicated that the compounds containing diphosphines ligands are more stable towards oxidation than compound (1).

Some cyclopalladated compounds containing the azido group ligand and the (C-N) ring of N,N-dimethylbenzylamine have been prepared by bridge opening reactions of dimmer azide complex precursor with some diphosphines in different stoichiometric quantities. The neutral or ionic, mono or binuclear complexes synthesized were characterized by elemental analyses, I. R. spectroscopy and NMR techniques. The series of complexes was screened for cytotoxicity against a panel three human tumour cells lines(C6,Hep-2,HeLa). All complexes were found to be cytotoxic (IC50) at µM concentrations while one complex having the coordination bond N-Pd ruptured also displayed some differential cytotoxicity.