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The cocrystallization of active pharmaceutical ingredients (APIs) is known to be a technique suitable for overcoming certain physicochemical issues concerning the solid forms of drugs. In the case of the cocrystal of 5-fluorocytosine and isoniazid, two widely used active pharmaceutical ingredients, for example, the cocrystallization improved the phase stability of the latter against moisture, thus increasing its shelf life. The room-temperature crystal structure was already reported in the literature, but no charge density study has been published so far. To further evaluate the structural properties of this potential codrug, which is stabilized by a supramolecular synthon containing N–H···N-type hydrogen bonds, here we performed the experimental and theoretical charge density analyses of the drug–drug cocrystal formed by the antimetabolite prodrug 5-fluorocytosine and the tuberculostatic drug isoniazid. Topological analyses were also performed for all models and compared, indicating a good agreement between experiment and theory. The comparison with gas-phase calculations enabled the evaluation of the charge redistribution upon cocrystallization as well as the effect of the intermolecular interactions. In this manner, it was possible to evaluate the variations in bond distances and electron densities at the bonds involved in the intermolecular heterosynthon. Through the total charge of each molecule in the cocrystal, it was also possible to have insights into the charge redistribution when both molecules crystallize together. Electrostatic potential maps were also calculated for the experimental data and compared with the gas-phase calculations.

The untapped potential of α-carbonyl sulfoxonium ylides in epoxide ring-opening reactions has been a notable gap in current research, with such reactivity predominantly associated with the highly reactive dimethylsulfoxonium methylide. This study introduces an innovative approach wherein an epoxide indole, formed in situfrom 2-hydroxyindoline-3-triethylammonium bromide, undergoes reaction with α-ester sulfoxonium ylides. The outcome is the efficient synthesis of a range of 2-hydroxyindolin-3-ylidenes, demonstrating favorable yields (41–81%) and Z/Eratios from 4:1 to those of exclusive Zisomers. Additionally, the photophysical properties of the synthesized indolinylidenes are explored, along with their derivatization using various nucleophiles under acid catalysis.

A green methodology was developed to obtain a large scope of Knoevenagel adducts with high yields (77-95%). The compounds were synthetized in 30 min, using aromatic aldehyde derivatives, malononitrile, water as a solvent, microwave irradiation as a heating source and in free-catalyst conditions. In a particular case, in the synthesis of the adduct derived from the α-methyl-trans-cinnamaldehyde, a [2+2] photochemical cycloaddition product was observed, a tetrasubstituted cyclobutane dimeric compound 3w’. Its complex structure was confirmed by X-ray diffraction (first time), nuclear magnetic resonance analysis and electronic structure calculations. Theoretical results suggest that the thermal decomposition of 3w’ back to 3w can occur by means of a biradical intermediate.

Fluoxetine (Flx), an important active pharmaceutical ingredient (API) for the treatment of depression, is commercially available as a racemic hydrochloride salt. Interestingly, the spontaneous resolution of RS-Flx occurred upon salt formation with oxalic acid (H2Oxa). Single crystals of Flx hydrogen-oxalate salt (Flx HOxa) have been obtained by slow evaporation from solution. They have been examined by single-crystal and powder X-ray diffraction, chiral chromatography, thermal analysis, and equilibrium solubility, revealing that Flx HOxa salt crystallizes as a racemic conglomerate. In the salt structure, the Flx+··· HOxa–ionic pairs assemble in 21-helical chains in the Sohncke space group P21and Z’ = 1, through N+H···O–H-bonds. Additional cationic homochiral chains are formed in the crystals through noncovalent interactions between helicoidal motifs. It was shown that Flx HOxa conglomerates are as thermally stable as the hydrochloride salt of Flx, confirmed by thermal analysis. The identification of Flx HOxa salt conglomerates is a crucial step for the further chiral resolution process for the API and is also a novel multicomponent crystal with promising properties for a new drug formulation.

Pharmaceutical cocrystals have emerged over the past several decades as an alternative path for synthesizing stable and/or improved crystalline forms of active pharmaceutical ingredients. In this contribution, we developed a reproducible cocrystallization path for the supramolecular synthesis of four new pharmaceutical cocrystal forms of fluconazole (FLZ), an antifungal multifunctional drug: fluconazole–fumaric acid monohydrate (1:1:1), fluconazole–malic acid (1:1), fluconazole–dipicolinic acid (1:1), and fluconazole–adipic acid (1:1). All the new cocrystals were characterized by powder/single-crystal X-ray diffraction, Raman, Fourier transform infrared spectroscopy, differential scanning calorimetry/thermogravimetric analysis, and hot-stage polarized optical microscopy, and their water solubility was determined. Structurally, although the coformers were different, the same strong O–H···N hydrogen bond between the FLZ molecule and the coformers was observed. The aqueous solubility studies revealed that all the cocrystals were found to exhibit improved aqueous solubility when compared to the commercialized FLZ polymorph.

Famotidine (FMT) and ibuprofen (IBU) were used as model drugs to obtain coamorphous systems, where the guanidine moiety of the antacid and the carboxylic group of the nonsteroidal anti-inflammatory drug could potentially participate in H-bonds leading to a given structural motif. The systems were prepared in 3:7, 1:1, and 7:3 FMT and IBU molar ratios, respectively. The latter two became amorphous after 180 min of comilling. FMT–IBU (1:1) exhibited a higher physical stability in assays at 4, 25, and 40 °C up to 60 days. Fourier transform infrared spectroscopy accounted for important modifications in the vibrational behavior of those functional groups, allowing us to ascribe the skill of 1:1 FMT–IBU for remaining amorphous to equimolar interactions between both components. Density functional theory calculations followed by quantum theory of atoms in molecules analysis were then conducted to support the presence of the expected FMT–IBU heterodimer with consequent formation of a R228 structural motif. The electron density (ρ) and its Laplacian (∇2ρ) values suggested a high strength of the specific intermolecular interactions. Molecular dynamics simulations to build an amorphous assembly, followed by radial distribution function analysis on the modeled phase were further employed. The results demonstrate that it is a feasible rational design of a coamorphous system, satisfactorily stabilized by molecular-level interactions leading to the expected motif.

Mechanochemistry synthesis was applied to the supramolecular synthesis and green scale-up production of a 1:1 drug–drug cocrystal involving the antimetabolite prodrug 5-Fluorocytosine (5-FC) and the tuberculostatic drug Isoniazid (INH), namely, 5FC-INH. Crystalline material, also obtained by traditional slow evaporation methods, was analyzed by single-crystal X-ray diffraction (XRD). The crystal packing is stabilized by a classical N–H···N hydrogen-bond interaction between the amine moiety of 5-FC and the INH pyridine nitrogen. IR and Raman data provided spectroscopic evidence about the hydrogen atom positions, thereby confirming the neutral nature of the cocrystal. Furthermore, 5FC-INH codrug was also evaluated by a range of analytical techniques such as powder XRD and thermal (thermogravimetric analysis, differential scanning calorimetry, hot stage microscopy) analyses. A physical stability study was performed in high relative humidity conditions to verify possible 5-FC solid-state hydration and/or INH degradation. The equilibrium solubility of this codrug was compared to the anhydrous 5-FC and INH raw materials, in pH 1.2 buffer media, and it was found to be similar to that of 5-FC, a biopharmaceutics classification system class I drug. The results show that the cocrystal has superior phase stability properties against moisture when compared to the starting pharmaceutical ingredients, so it could be considered as a potential candidate for the treatment of concomitant fungal infections, tuberculosis, and cancer.

A series of copper(I)–phosphine polypyridyl complexes have been investigated as potential antitumor agents. The complexes [Cu(PPh3)2dpq]NO3(2), [Cu(PPh3)2dppz]NO3(3), [Cu(PPh3)2dppa]NO3(4), and [Cu(PPh3)2dppme]NO3(5) were synthesized by the reaction of [Cu(PPh3)2NO3] with the respective planar ligand under mild conditions. These copper complexes were fully characterized by elemental analysis, molar conductivity, FAB-MS, and NMR, UV–vis, and IR spectroscopies. Interactions between these copper(I)–phosphine polypyridyl complexes and DNA have been investigated using various spectroscopic techniques and analytical methods, such as UV–vis titrations, thermal denaturation, circular dichroism, viscosity measurements, gel electrophoresis, and competitive fluorescent intercalator displacement assays. The results of our studies suggest that these copper(I) complexes interact with DNA in an intercalative way. Furthermore, their high protein binding affinities toward human serum albumin were determined by fluorescence studies. Additionally, cytotoxicity analyses of all complexes against several tumor cell lines (human breast, MCF-7; human lung, A549; and human prostate, DU-145) and non-tumor cell lines (Chinese hamster lung, V79-4; and human lung, MRC-5) were performed. The results revealed that copper(I)–phosphine polypyridyl complexes are more cytotoxic than the corresponding planar ligand and also showed to be more active than cisplatin. A good correlation was observed between the cytostatic activity and lipophilicity of the copper(I) complexes studied here.

Upon exploration of the chemistry of the combination of ruthenium/arene with anthraquinone alizarin (L), three new complexes with the general formulas [Ru(L)Cl(η6-p-cymene)] (C1), [Ru(L)(η6-p-cymene)(PPh3)]PF6(C2), and [Ru(L)(η6-p-cymene)(PEt3)]PF6(C3) were synthesized and characterized using spectroscopic techniques (mass, IR, and 1D and 2D NMR), molar conductivity, elemental analysis, and X-ray diffraction. Complex C1exhibited fluorescence, such as free alizarin, while in C2and C3, the emission was probably quenched by monophosphines and the crystallographic data showed that hydrophobic interactions are predominant in intermolecular contacts. The cytotoxicity of the complexes was evaluated in the MDA-MB-231 (triple-negative breast cancer), MCF-7 (breast cancer), and A549 (lung) tumor cell lines and MCF-10A (breast) and MRC-5 (lung) nontumor cell lines. Complexes C1and C2were more selective to the breast tumor cell lines, and C2was the most cytotoxic (IC50= 6.5 μM for MDA-MB-231). In addition, compound C1performs a covalent interaction with DNA, while C2and C3present only weak interactions; however, internalization studies by flow cytometry and confocal microscopy showed that complex C1does not accumulate in viable MDA-MB-231 cells and is detected in the cytoplasm only after cell permeabilization. Investigations of the mechanism of action of the complexes indicate that C2promotes cell cycle arrest in the Sub-G1phase in MDA-MB-231, inhibits its colony formation, and has a possible antimetastatic action, impeding cell migration in the wound-healing experiment (13% of wound healing in 24 h). The in vivotoxicological experiments with zebrafish indicate that C1and C3exhibit the most zebrafish embryo developmental toxicity (inhibition of spontaneous movements and heartbeats), while C2, the most promising anticancer drug in the in vitropreclinical tests, revealed the lowest toxicity in in vivopreclinical screening.

TbIIIand EuIIIsystems have been investigated as ratiometric luminescent temperature probes in luminescent coordination polymers due to TbIII→ EuIIIenergy transfer (ET). To help understand how ion–ion separation, chain conformation as well as excitation channel impact their thermometric properties, herein, [Eu(tfaa)3(μ-L)Tb(tfaa)3]none-dimensional (1D) coordination polymers (tfaa–= trifluoroacetylacetonate, and L = [(diphenylphosphoryl)R](diphenyl)phosphine oxide, R = ethyl – dppeo – or butyl – dppbo) were synthesized. The short μ-dppeo bridge ligand leads to a more linear 1D polymeric chain, while the longer μ-dppbo bridge leads to tighter packed chains. As the temperature rises from 80 K, upon direct TbIIIexcitation at 488 nm, the TbIIIemission intensity decreases, while the EuIIIemission intensity increases after 160 and 200 K when L = dppeo or dppbo, respectively. The temperature-dependent emission intensities, due to TbIII→ EuIIIET, enable the development of ratiometric luminescent temperature probes featuring maximum relative thermal sensitivity up to 3.8% K–1(250 K, L = dppbo, excitation at 488 nm). On the other hand, the same system displays maximum thermal sensitivity up to 3.5% K–1(323 K) upon ligand excitation at 300 nm. Thus, by changing the excitation channel and bridge ligand that leads to modification of the polymer conformations, the maximum relative thermal sensitivity can be tuned.

ABSTRACTcis-[RuCl(NO2)(dppb)(5,5′-mebipy)] (complex 1), cis-[Ru(NO2)2(dppb)(5,5′-mebipy)] (complex 2), ct-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 3), and cc-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 4), where 5,5′-mebipy is 5,5′-dimethyl-2,2′-bipyridine and dppb is 1,4-bis(diphenylphosphino)butane, were synthesized and characterized. The structure of complex 2 was determined by X-ray crystallography. These complexes exhibited a higher anti-Trypanosoma cruziactivity than benznidazole, the current antiparasitic drug. Complex 3 was the most potent, displaying a 50% effective concentration (EC50) of 2.1 ± 0.6 μM against trypomastigotes and a 50% inhibitory concentration (IC50) of 1.3 ± 0.2 μM against amastigotes, while it displayed a 50% cytotoxic concentration (CC50) of 51.4 ± 0.2 μM in macrophages. It was observed that the nitrosyl complex 3, but not its analog lacking the nitrosyl group, releases nitric oxide into parasite cells. This release has a diminished effect on the trypanosomal protease cruzain but induces substantial parasite autophagy, which is followed by a series of irreversible morphological impairments to the parasites and finally results in cell death by necrosis. In infected mice, orally administered complex 3 (five times at a dose of 75 μmol/kg of body weight) reduced blood parasitemia and increased the survival rate of the mice. Combination index analysis of complex 3 indicated that its in vitroactivity against trypomastigotes is synergic with benznidazole. In addition, drug combination enhanced efficacy in infected mice, suggesting that ruthenium-nitrosyl complexes are potential constituents for drug combinations.

This work presents an innovative approach to obtain a multifunctional hybrid material operating via combined anti-Stokes (upconversion) and Stokes (downshifting) emissions for oxygen gas sensing and related functionalities. The material is based on a Cu(I) complex exhibiting thermally activated delayed fluorescence emission (TADF) and infrared-to-visible upconverting Tm3+/Yb3+-doped NaYF4nanoparticles supported in a polystyrene (PS) matrix. Excitation of the hybrid material at 980 nm leads to efficient transfer of Tm3+emission in the ultraviolet/blue region to the Cu(I) complex and consequently intense green emission (560 nm) of the latter. Additionally, the green emission of the complex can also be directly generated with excitation at 360 nm. Independently of the excitation wavelength, the emission intensity is efficiently suppressed by the presence of molecular oxygen and the quenching rate is properly characterized by the Stern–Volmer plots. The results indicate that the biocompatible hybrid material can be applied as an efficient O2sensor operating via near-infrared or ultraviolet excitation, unlike most optical oxygen sensors currently available which only work in downshifting mode.

Hydrokenomicrolite, (?,H2O)2Ta2(O,OH)6(H2O) or ideally ?2Ta2[O4(OH)2](H2O), is a new microlite-group mineral approved by the CNMNC (IMA 2011-103). It occurs as an accessory mineral in the Volta Grande pegmatite, Nazareno, Minas Gerais, Brazil. Associated minerals are: microcline, albite, quartz, muscovite, spodumene, “lepidolite”, cassiterite, tantalite-(Mn), monazite-(Ce), fluorite, “apatite”, beryl, “garnet”, epidote, magnetite, gahnite, zircon, “tourmaline”, bityite, and other microlite-group minerals under study. Hydrokenomicrolite occurs as euhedral octahedral crystals, occasionally modified by rhombododecahedra, untwinned, from 0.2 to 1.5 mm in size. The crystals are pinkish brown and translucent; the streak is white, and the luster is adamantine to resinous. It is non-fluorescent under ultraviolet light. Mohs hardness is 4½-5, tenacity is brittle. Cleavage is not observed; fracture is conchoidal. The calculated density is 6.666 g/cm3. The mineral is isotropic, ncalc= 2.055. The infrared spectrum contains bands of O-H stretching vibrations and H-O-H bending vibrations of H2O molecules. The chemical composition (n = 3) is [by wavelength-dispersive spectroscopy (WDS), H2O calculated from crystal-structure analysis, wt%]: CaO 0.12, MnO 0.27, SrO 4.88, BaO 8.63, PbO 0.52, La2O30.52, Ce2O30.49, Nd2O30.55, Bi2O30.57, UO24.54, TiO20.18, SnO22.60, Nb2O52.18, Ta2O566.33, SiO20.46, Cs2O 0.67, H2O 4.84, total 98.35. The empirical formula, based on 2 cations at the B site, is [?0.71(H2O)0.48Ba0.33Sr0.27U0.10Mn0.02Nd0.02Ce0.02La0.02Ca0.01Bi0.01Pb0.01]S2.00(Ta1.75Nb0.10Sn0.10Si0.04Ti0.01)S2.00[(O5.77(OH)0.23]S6.00[(H2O)0.97Cs0.03]S1.00. The strongest eight X-ray powderdiffraction lines [d in Å(I)(hkl)] are: 6.112(86)(111), 3.191(52)(311), 3.052(100)(222), 2.642(28)(400), 2.035(11)(511)(333), 1.869(29)(440), 1.788(10)(531), and 1.594(24)(622). The crystal structure refinement (R1= 0.0363) gave the following data: cubic, Fd3¯m, a = 10.454(1) Å, V = 1142.5(2) Å3, Z = 8. The Ta(O,OH)6octahedra are linked through all vertices. The refinement results and the approximate empirical bond-valences sums for the positions A (1.0 v.u.) and Y' (0.5 v.u.), compared to valence calculations from electron microprobe analysis (EMPA) and ranges expected for H2O molecules, confirm the presence of H2O at the A(16d) site and displaced from the Y(8b) to the Y'(32e) position. The mineral is characterized by H2O dominance at the Y site, vacancy dominance at the A site, and Ta dominance at the B site.

This work describes the atropisomeric relationships of 3‐methyl‐5‐(3‐methyl‐5‐phenyl‐1H‐pyrazol‐1‐yl)‐1‐phenyl‐1H‐pyrazol‐4‐amine (2d), which belongs to series 4‐aminobipyrazole derivatives designed as anti‐inflammatory agents. The 1H nuclear magnetic resonance spectra obtained in the presence of a chiral lanthanide shift salt associated to chiral high‐performance liquid chromatography analysis, X‐ray diffraction, and molecular modeling tools confirmed that orthobis‐functionalized bipyrazole 2dexists as a mixture of aR,aS‐atropisomers. These results provide useful information to understand the pharmacological profile of this derivative and of other 4‐aminobipyrazole analogs. Chirality 24:463–470, 2012.© 2012 Wiley Periodicals, Inc.

A new occurrence of rankamaite is here described at the Urubu pegmatite, Itinga municipality, Minas Gerais, Brazil. The mineral forms cream-white botryoidal aggregates of acicular to fibrous crystals, intimately associated with simpsonite, thoreaulite, cassiterite, quartz, elbaite, albite, and muscovite. The average of six chemical analyses obtained by electron microprobe is (range in parentheses, wt%): Na2O 2.08 (1.95-2.13), K2O 2.61 (2.52-2.74), Al2O31.96 (1.89-2.00), Fe2O30.01 (0.00-0.03), TiO20.02 (0.00-0.06), Ta2O581.04 (79.12-85.18), Nb2O59.49 (8.58-9.86), total 97.21 (95.95-101.50). The chemical formula derived from this analysis is (Na1.55K1.28)Σ2.83(Ta8.45Nb1.64Al0.89Fe3+0.01Ti0.01)Σ11.00[O25.02(OH)5.98]Σ31.00. Rankamaite is an orthorhombic “tungsten bronze” (OTB), crystallizing in the space group Cmmm. Its unit-cell parameters refined from X‑ray diffraction powder data are: a = 17.224(3), b = 17.687(3), c = 3.9361(7) Å, V = 1199.1(3) Å3, Z = 2. Rietveld refinement of the powder data was undertaken using the structure of LaTa5O14as a starting model for the rankamaite structure. The structural formula obtained with the Rietveld analyses is: (Na2.21K1.26)Σ3.37(Ta9.12Nb1.30Al0.59)Σ11.00[O26.29(OH)4.71]Σ31.00. The tantalum atoms are coordinated by six and seven oxygen atoms in the form of distorted TaO6octahedra and TaO7pentagonal bipyramids, respectively. Every pentagonal bipyramid shares edges with four octahedra, thus forming Ta5O14units. The potassium atom is in an 11-fold coordination, whereas one sodium atom is in a 10-fold and the other is in a 12-fold coordination. Raman and infrared spectroscopy were used to investigate the room-temperature spectra of rankamaite.

2,3‐Dihydroxynaphthalene (H2dhn) reacts with [ReOCl3(PPh3)2] or [ReOBr3(PPh3)2] in a 1:1 molar ratio with formation of the isostructural complexes [ReOCl2(PPh3)2(Hdhn)] (4) and [ReOBr2(PPh3)2(Hdhn)] (5). They have distorted octahedral coordination spheres with the halide and the triphenylphosphine ligands arranged in equatorial transpositions to each other. The Hdhn–ligand coordinates monodentately in transposition to the oxo ligand. Intramolecular hydrogen bonds between the Hdhn–and the halogeno ligands stabilize this coordination mode. The products represent the first examples of oxorhenium(V) complexes with monodentate catecholate‐type ligands.

Five novel organotin complexes with the anthraquinone dyes alizarin (1,2‐dihydroxyanthraquinone) and purpurin (1,2,4‐trihydroxyanthraquinone) were synthesized and characterized by elemental analyses, FTIR and NMR spectroscopy (1H, 13C and 119Sn). The crystal and molecular structures of four complexes were determined by X‐ray diffraction on single crystals: [Bu2Sn(aliz)(H2O)]·C2H5OH (A1·EtOH), [Bu2Sn(aliz)(dmso)]2(A3), [(Bu2Sn)3O(Hpurp)2] (P1) and [Bu2Sn(Hpurp)(dmso)]2(P2), where H2aliz = alizarin and H3purp = purpurin. The coordination mode of the ligands is identical to that found in their Al/Ca complexes, where they act as dianionic tridentate ligands forming five and six‐membered fused chelate rings. The coordination to the tin atoms occurs exclusively viathe 1,2‐ phenolate oxygen and the adjacent quinoid oxygen atoms. The complexes A1, A3and P1are dimers with hepta‐coordinated tin atoms in form of a slightly distorted pentagonal bipyramid. The trinuclear complex P2contains two pentacoordinated and one heptacoordinated tin atoms.

Ethylenediaminetetraacetic acid (H4EDTA) is widely used in the pharmaceutical and bromatological industries and as a drug in chelation therapies. Besides, coordinated with metal ions it is used for the supplementation of essential trace elements. In this work the synthesis, crystallographic, and spectroscopic studies (EPR, IR, UV/Vis) of [Zn(H2O)4CuEDTA] · 2H2O are reported. The release of the metal cations at gastric pH was also investigated.

This work reports the synthesis and characterization of a new copper complex with nadolol, a betablocker aminoalcohol. The stoichiometry found was Na[Cu(nadololate)(CO3)] · H2O. Electronic and vibrational spectroscopy analysis was performed, and the crystal structure of Na[Cu(nadololate)-(CO3)] · H2O was determined by X-ray diffraction.

The alkaline earth tricyanomethanides Mg(tcm)2· 2H2O, Ca(tcm)2, Sr(tcm)2·H2O and Ba(tcm)2· 2H2O were prepared from aqueous solutions of the respective chlorides and silver tricyanomethanide. Their IR spectra and thermal behavior are described. The crystal structures of Ca(tcm)2and Ba(tcm)2· 2H2O were determined by single crystal X-ray diffraction. The structure of Ca(tcm)2is of the type found for several transition metal tricyanomethanides [1], containing two independent interpenetrating networks. Ba(tcm)2· 2H2O has a unique crystal structure corresponding to a three-dimensional coordination polymer with nine fold coordinated Ba atoms connected by water molecules and tricyanomethanide anions.

Menezesite, ideally Ba2MgZr4(BaNb12O42)·12H2O, occurs as a vug mineral in the contact zone between dolomite carbonatite and “jacupirangite” (=a pyroxenite) at the Jacupiranga mine, in Cajati county, São Paulo state, Brazil, associated with dolomite, calcite, magnetite, clinohumite, phlogopite, ancylite-(Ce), strontianite, pyrite, and tochilinite. This is also the type locality for quintinite-2H. The mineral forms rhombododecahedra up to 1 mm, isolated or in aggregates. Menezesite is transparent and displays a vitreous luster; it is reddish brown with a white streak. It is non-fluorescent. Mohs hardness is about 4. Calculated density derived from the empirical formula is 4.181 g/cm3. It is isotropic, nmeas> 1.93(1) (white light); ncalc= 2.034. Menezesite exhibits weak anomalous birefringence. The empirical formula is (Ba1.47K0.53Ca0.31Ce0.17Nd0.10Na0.06La0.02)Σ2.66(Mg0.94Mn0. 23Fe0.23Al0.03)Σ1.43(Zr2.75Ti0.96Th0.29)Σ4.00[(Ba0.72Th0.26U0.02)Σ1.00(Nb9.23Ti2.29Ta0.36Si0.12)Σ12.00O42]·12H2O. The mineral is cubic, space group Im3̅ (204), a = 13.017(1) Å, V = 2206(1) Å3, Z = 2. Menezesite is isostructural with the synthetic compound Mg7[MgW12O42](OH)4·8H2O. The mineral was named in honor of Luiz Alberto Dias Menezes Filho (born 1950), mining engineer, mineral collector and merchant. Both the description and the name were approved by the CNMMN-IMA (Nomenclature Proposal 2005-023). Menezesite is the first natural heteropolyniobate. Heteropolyanions have been employed in a range of applications that include virus-binding inorganic drugs (including the AIDs virus), homogeneous and heterogeneous catalysts, electro-optic and electrochromic materials, metal and protein binding, and as building blocks for nanostructuring of materials.

The reaction of the bis(thiosemicarbazone) of dimethyl pyridine-2,6-diyl diketone, H2DAPTSC, with PbMe2(OAc)2, PbMePh(OAc)2 or PbPh2(OAc)2 in MeOH afforded the complexes [PbMe2(DAPTSC)], [PbMePh(DAPTSC)] or [PbPh2(DAPTSC)] (in the first two cases together with [Pb(DAPTSC)]). X-ray crystallography of the Pb(IV) complexes showed that the metal has a pentagonal bipyramidal coordination sphere. The N3,S2-bound DAPTSC2– anion occupied the equatorial plane and the organic groups were in the apical positions. These compounds retain the same coordination mode in DMSO solution. DAPTSC2– is also N3,S2-bound in [Pb(DAPTSC)], a complex with a stereochemically active PbII lone pair. The reaction of PbPh2Cl2 with H2DAPTSC, also in methanol at room temperature, afforded [PbPh2(H2DAPTSC)]2[PbPh2Cl4]Cl2·6CH3OH. X-ray crystallography of this centrosymmetric complex showed it to consist of two [PbPh2(H2DAPTSC)]2+ cations of similar structure to the neutral [PbR2(DAPTSC)] complexes, together with a trans-octahedral [PbPh2Cl4]2– anion and two Cl– anions. This compound decomposes in DMSO solution, probably evolving to H2DAPTSC and PbPh2Cl2(DMSO)n. In order to evaluate the changes undergone by H2DAPTSC under metallation, the X-ray structure of the free molecule was also determined.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Matioliite, ideally NaMgAl5(PO4)4(OH)6·2H2O, occurs as a secondary hydrothermal mineral in the Gentil mine granite pegmatite, Mendes Pimentel Co., Minas Gerais, Brazil. Some crystals are zoned to more Fe-rich compositions with an Fe2+:Mg ratio of approximately 1:1, corresponding to an intermediate member of the burangaite-matioliite solid-solution series. Matioliite is intimately associated with fluorapatite, crandallite, and zoned gormanite-souzalite cystals. The mineral forms prismatic to tabular crystals, up to 1 mm long. Matioliite is transparent and displays a vitreous luster; it is blue to colorless with a white streak. It is non-fluorescent. Mohs hardness is about 5. Calculated density is 2.948 g/cm3. Matioliite is biaxial negative, ηα= 1.597(2), ηβ= 1.627(2), ηγ= 1.632(1) (white light), 2V (meas.) = 43(2)°, 2V (calc.) = 44°, dispersion r > v, orientation X = b, Z ^ c = 6°. Pleochroism is Y > X > Z, X = light blue to colorless, Y = blue, Z = colorless. The empirical formula is (Na0.94Ca0.01)Σ0.95(Mg0.88Fe2+0.11Mn0.01)Σ1.00(Al4.84Fe3+0.13)Σ4.97(PO4)4.03(OH)5.76·2H2O. The mineral is monoclinic, space group C2/c, a = 25.075(1) Å, b = 5.0470(3) Å, c = 13.4370(7) Å, β = 110.97(3)°, V = 1587.9(4) Å3, Z = 4. Crystal-structure determination was carried out and showed it is isostructural with burangaite, dufr énite, and natrodufrénite. Both the description and the name were approved by the CNMMN-IMA (Nomenclature Proposal 2005-011). The .magnesium analog of burangaite. described from the Gold Quarry mine, Carlin-trend, Eureka County, Nevada; “burangaite” from Hochgosch, Millstätter See-Rücken, Kärnten, Austria; and .burangaite. described from Córrego Pomarolli, Linópolis, Divino das Laranjeiras, Minas Gerais, Brazil, are probably matioliite.

The reactions of the ligands 2,6-diacetylpyridine bis(S-methyldithiocarbazate)] (H2dapmdtc) and 2,6-diacetylpyridine bis(S-benzyldithiocarbazate)] (H2dapbdtc) with R4-mSnClm(R = Me, nBu, Ph; and m= 2) led to the formation of six seven-coordinate diorganotin(IV) complexes, which were studied by microanalysis, i.r., n.m.r (1H, 119Sn) and Mössbauer spectroscopies. The X-ray structures determination of complexes [Me2Sn(dapmdtc)], [Me2Sn(dapbdtc)] and [Ph2Sn(dapbdtc)] revealed the presence of neutral seven-coordinated complexes. The structures consist of monomeric units in which the Sn(IV) atom exhibits distorted pentagonal bipyramidal (PBP) geometry, with the S,N,N,N,S-donor systems of the ligands lying in the equatorial plane and organic groups in the apical positions. A correlation between Mössbauer and X-ray data based on the point-charge model is discussed.The reactions of the ligands 2,6-diacetylpyridine bis(S-methyldithiocarbazate)] (H2dapmdtc) and 2,6-diacetylpyridine bis(S-benzyldithiocarbazate)] (H2dapbdtc) with R4-mSnClm(R = Me, nBu, Ph; and m= 2) led to the formation of six seven-coordinate diorganotin(IV) complexes, which were studied by microanalysis, i.r., n.m.r (1H, 119Sn) and Mössbauer spectroscopies. The X-ray structures determination of complexes [Me2Sn(dapmdtc)], [Me2Sn(dapbdtc)] and [Ph2Sn(dapbdtc)] revealed the presence of neutral seven-coordinated complexes. The structures consist of monomeric units in which the Sn(IV) atom exhibits distorted pentagonal bipyramidal (PBP) geometry, with the S,N,N,N,S-donor systems of the ligands lying in the equatorial plane and organic groups in the apical positions. A correlation between Mössbauer and X-ray data based on the point-charge model is discussed.