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Herein, we describe the preparation of heteronuclear dirhodium-silver complexes by reaction between molecular Rh(II)-Rh(II) compounds [Rh2(μ-O2CR)4L2] (R = Me, Ph (1), CH2OEt (2); L = solvent molecules) with paddlewheel structure and PPh4[Ag(CN)2]. One-dimensional coordination polymers of (PPh4)n[Rh2(μ-O2CR)4Ag(CN)2]n (R = Me (3), Ph (4), CH2OEt (5)) formula have been obtained by replacement of the two labile molecules in the axial positions of the paddlewheel structures by a [Ag(CN)2]− bridging unit. The crystal structures of 3–5 display a similar arrangement, having anionic chains with a wavy structure and bulky (PPh4)+ cations placed between the chains. The presence of the (PPh4)+ cations hinders the existence of intermolecular Ag-Ag interactions although several C-H····π interactions have been observed. A similar reaction between [Rh2(μ-O2CCMe3)4(HO2CCMe3)2] and PPh4[Ag(CN)2] led to the molecular compound (PPh4)2{Rh2(μ-O2CCMe3)4[Ag(CN)2]2} (6) by replacement of the axial HO2CCMe3 ligands by two [Ag(CN)2]− units. The trimethylacetate ligand increases the solubility of the complex during the crystallization favouring the formation of discrete heteronuclear species.

The mesoporous silica-based material SBA-15 (Santa Barbara Amorphous-15) has been modified with the aminodiol ligand 3-[bis(2-hydroxyethyl)amino]propyltriethoxysilane (PADOH) to give the corresponding material SBA-PADOH. Subsequent functionalization with a diorganotin(iv) compound, SnPh2Cl2 (1), and with two titanocene derivatives, TiCp2Cl2 ([Ti(η5-C5H5)2Cl2] (2)) and TiCpCpPhNfCl2 ([Ti(η5-C5H5)(η5-C5H4CHPhNf)Cl2] (3) (Ph = C6H5; Nf = C10H7)), gave the materials SBA-PADO-SnPh2 (M1), SBA-PADO-TiCp2 (M2) and SBA-PADO-TiCpCp* (M3), respectively. SBA-PADOH and M1-M3 have been characterized by various techniques such as FT-IR, XRD, XRF, solid-state NMR, nitrogen adsorption-desorption isotherms, electrochemical methods, SEM and TEM, observing that the functionalization has mainly taken place inside the pores of the corresponding porous system. In addition, mechanistic aspects of the apoptosis triggered by the synthesized materials have been studied in vitro in tumour cell lines derived from three distinct types of cancer in order to elucidate their growth inhibition and interference with the expression of tumour necrosis factor alfa (TNF-α) and the first apoptosis signal receptor (Fas or tumour necrosis factor receptor 6). It was observed that the antiproliferative and proapoptotic capacity of the materials depends on their functionalization with the different cytotoxic prodrugs (organotin or titanocene derivatives). The study shows that M1-M3 influence the metabolic activity of the tumour cells and modulate the apoptotic pathways by different mechanisms, according to the active compound inside the material.

Mercury superconductor samples doped with rhenium, Hg0.82Re0.18Ba2Ca2Cu3O8+d, were produced in a very narrow range of oxygen content (d = 0.05, 0.10 and 0.15). The lattice parameters indicated a slight change of the unitary cell as a function of the oxygen content. Furthermore, the reduction of the volume cell was associated with the slight increment of TC. The measurements of χac versus temperature, under external hydrostatic pressure, have shown sensitive results as a function of distinct oxygen content. In our opinion, this kind of measurement may be used as a tool to determine the oxygen content (underdoped, optimal or overdoped) of samples. For dTC/dP > 1.9 K GPa−1 the sample presents an underdoped oxygen content. One can understand that dTC/dP = (1.9 ± 0.2) K GPa−1 is associated with an intrinsic term value for the optimal oxygen doped sample, Hg0.82Re0.18Ba2Ca2Cu3O8.10.

X-ray powder diffraction was used to study the phase composition of human renal calculi. The stones were collected from 56 donors in Vitória, Espírito Santo state, southeastern Brazil. An XRD phase quantification revealed that 61% of the studied renal stones were composed exclusively of calcium oxalate ͓34% formed only by calcium oxalate monohydrate ͑COM͒ and 27% presents both monohydrate and dihydratate calcium oxalate͔. The 39% multi-composed calculi have various other phases such as uric acid and calcium phosphate. Rietveld refinement of XRD data of one apparent monophasic ͑COM͒ renal calculus revealed the presence of a small amount of hydroxyapatite. The presence of this second phase and the morphology of the stone ͑ellipsoidal͒ indicated that this calculus can be classified as non-papillary type and its nucleation process developed in closed kidney cavities. In order to show some advantages of the X-ray powder diffraction technique, a study of the phase transformation of monohydrate calcium oxalate into calcium carbonate ͑CaCO 3 ͒ was carried out by annealing of a monophasic COM calculi at 200, 300, and 400°C for 48 h in a N 2 gas atmosphere. The results of the XRD for the heat treated samples is in good agreement with the thermogravimetric analysis found in the literature and shows that X-ray powder diffraction can be used as a suitable technique to study the composition and phase diagram of renal calculi.