64520-44-1

Upstream product

• 58328-36-2 N,N-diethyl-N'-benzoyl-thiourea 
• 10025-98-6 potassium tetrachloropalladate(II) 

Relevant academic research and scientific papers

Understanding the mechanism of cis–trans isomerism in photo-active palladium(II) complexes derived from the N,N-di-substituted benzoylthioureas

The reaction of a series of N,N-di-substituted aroylthioureas (HL1?3; L1 = H, L2 = Cl, L3 = OMe) with the Pd(II) centre in K2PdCl4 leads to cis-[Pd(L1?3-κS,O)2] complexes exclusively which then undergoes photo-induced isomerism to the trans-[Pd(L1?3-κS,O)2] isomer upon broadband UV irradiation. The photochemical isomerization allows these unstable trans-[Pd(L1?3-κS,O)2] products to be isolated in pure forms if the conversion is completed in acetonitrile after slow evaporation of the solvent. The molecular structures of both cis-[Pd(L2-κS,O)2] and trans-[Pd(L2-κS,O)2] isomers have been determined by single-crystal X-ray diffraction. Upon dissolving trans-[Pd(L1?3-κS,O)2] in chloroform in the dark, spontaneous trans → cis isomerism occurs. In-situ laser photolysis in conjunction with NMR spectroscopy allows the time course of both these photochemical and thermal isomerisations to be monitored. The results indicate that a photostationary state is reached, that the back reaction is promoted both photochemically and thermally, and that the established photostationary state reverts back to the initial composition once photolysis stops. The presence of an electron-withdrawing chloro substituent on the para position of the phenyl ring increases the rate of the thermally initiated trans → cis isomerisation step. Furthermore, the addition of trace amounts of the HL1?3 ligands, a coordinating solvent or a two electron donor such as pyridine also speeds up this process in accordance with an associative mechanism. Mixed-ligand complexes were detected by reverse phase (RP) chromatography when cross-reactions were performed in accordance with this hypothesis. All the experimental evidence fits with a mechanism involving a competitive photochemical and associative ligand exchange.

Versatile coordination behavior of N,N-di(alkyl/aryl)-N′- benzoylthiourea ligands: Synthesis, crystal structure and cytotoxicity of palladium(II) complexes

The synthesis and characterization of Pd(II) complexes with the general formula cis-[Pd(L-O,S)2] (HL = N,N-diethyl-N′-benzoylthiourea, N,N-diisobutyl-N′-benzoylthiourea or N,N-dibenzyl-N′- benzoylthiourea) and trans-[PdCl2(HL-S)2] (HL = N,N-diphenyl-N′-benzoylthiourea, N,N-di-n-butyl-N′-benzoylthiourea or N,N-diisopropyl-N′-benzoylthiourea) are reported. These complexes were formed from the reaction between PdCl2 and N,N-di(alky/aryl)- N′-benzoylthiourea in acetonitrile with the formulation dependent on the nature of HL. The new Pd(II) complexes have been characterized by analytical and spectral (FT-IR, UV-Vis, 1H NMR and 13C NMR, Mass) techniques. The molecular structures of two of the complexes (1 and 5) have been conformed by X-ray crystallography. Complex 1 shows cytotoxicity against human breast cancer cells.

Liquid-liquid extraction of palladium(II) and gold(III) with N-benzoyl-N′,N′-diethylthiourea and the synthesis of a palladium benzoylthiourea complex

N-Benzoylthioureas have been reported to form complexes with gold (III) and palladium (II) and other transition metals. In this study, an N-benzoyl-N′,N′-diethylthiourea (3f) ligand was used in the solvent extraction of palladium(II) and gold(III) from aqueous chloride media (0.1 mol l-1 NaCl). The distribution coefficient was determined as a function of both metal concentration in the aqueous phase and extractant concentration in the organic phase. The experimental distribution data were numerically analysed by LETAGROP-DISTR software in order to obtain the thermodynamic model corresponding to the metal extraction. It is found that pH does not affect the metal extraction process in the 1-2 pH range. Synthesis of the palladium benzoyl thiourea complexes was carried out by mixing quantities of metal and ligand solutions in methanol in a 1:2 ratio stoichiometric. Yields of 74 and 80.9% were obtained for the Pd-3c and Pd-3f complexes. In order to confirm the formation of the palladium complexes, NMR, FTIR and MS analyses were performed. From MS analyses a complex stoichiometry 1:2 (metal:ligand) was confirmed. The formation of crystals of palladium N-benzoyl-N′,N′-diethylthiourea complex (Pd-3f) in the methanolic solution allows the characterisation of the complex structure by XRD. The resulting structure is described and discussed. Bis(1,1,-diheptadecyl-3-benzoyl-thioureate)palladium(II) (Pd-3c) and bis(1,1,-diheptadecyl-3-benzoyl-thioureate)palladium(II) (Pd-3f) were used as ionophores in polymeric membrane electrodes. Their potentiometric responses to different anionic metal chlorocomplexes are evaluated and discussed taking into consideration the results obtained in the liquid-liquid distribution studies. A nernstian response was only obtained for AuCl4-(PDL = 8.8 × 10-8) and PdCl42- (PDL = 1.5 × 10-4 M) with a selectivity coefficient of KAuCl4-, PdCl42-pot = -3.4, calculated taking AUCl4- as being the primary anion.