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The first in situ micro-Raman spectroscopic study of prehistoric drawings found in the cave of Rouffignac-Saint-Cernin (Dordogne, France) was carried out. Rouffignac cave art, assigned to the upper Magdalenian Paleolithic period (13500–12000 bp), is constituted of more than 250 drawings and engraving including 158 mammoths. There are about a hundred drawings, all made of black pigments. Until now, destructive chemical analyses performed on one sample, as well as recent micro X-ray fluorescence (μ-XRF) in situ analyses have shown that the drawings contain manganese oxides. Because no carbon has yet been found, no direct dating of the drawings could be performed. This new study of the Rouffignac cave using non-destructive in situ micro-analyses aims at confirming or not the absence of carbon-based drawings and at understanding the apparent homogeneity of the parietal representations by the identification of the crystalline phases constituting the black pigments. The adaptability of portable equipment as well as the feasibility of in situ micro-Raman analyses in a cave environment was tested. The results obtained are compared with in situ XRF, and X-ray diffraction microanalysis is performed at the same time in the cave. We demonstrate that a portable Raman instrument is very useful to analyze non-destructively drawings in the following difficult conditions: high humidity, various wall geometries, and small amounts of material studied. These results show that the black manganese oxides romanechite and pyrolusite were used as pigments by prehistorical artists. Carbon and carotenoids have been found locally. Differences between the various figures are highlighted and hypotheses about the drawings production are proposed. Copyright © 2012 John Wiley & Sons, Ltd.

A straightforward formation of six- and eight-membered rings via the radical cyclization of specifically designed ynamides is reported. This strategy provides a protoberberine analog in only three steps by a radical cyclization cascade.

New heterobimetallic tetranuclear complexes of formula [Fe(III){B(pz)(4)}(CN)(2)(μ-CN)Mn(II)(bpy)(2)](2)(ClO(4))(2)·CH(3)CN (1), [Fe(III){HB(pz)(3)}(CN)(2)(μ-CN)Ni(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (2a), [Fe(III){B(pz)(4)}(CN)(2)(μ-CN)Ni(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (2b), [Fe(III){HB(pz)(3)}(CN)(2)(μ-CN)Co(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (3a), and [Fe(III){B(pz)(4)}(CN)(2)(μ-CN)Co(II)(dmphen)(2)](2)(ClO(4))(2)·2CH(3)OH (3b), [HB(pz)(3)(-) = hydrotris(1-pyrazolyl)borate, B(Pz)(4)(-) = tetrakis(1-pyrazolyl)borate, dmphen = 2,9-dimethyl-1,10-phenanthroline, bpy = 2,2'-bipyridine] have been synthesized and structurally and magnetically characterized. Complexes 1-3b have been prepared by following a rational route based on the self-assembly of the tricyanometalate precursor fac-[Fe(III)(L)(CN)(3)](-) (L = tridentate anionic ligand) and cationic preformed complexes [M(II)(L')(2)(H(2)O)(2)](2+) (L' = bidentate α-diimine type ligand), this last species having four blocked coordination sites and two labile ones located in cis positions. The structures of 1-3b consist of cationic tetranuclear Fe(III)(2)M(II)(2) square complexes [M = Mn (1), Ni (2a and 2b), Co (3a and 3b)] where corners are defined by the metal ions and the edges by the Fe-CN-M units. The charge is balanced by free perchlorate anions. The [Fe(L)(CN)(3)](-) complex in 1-3b acts as a ligand through two cyanide groups toward two divalent metal complexes. The magnetic properties of 1-3b have been investigated in the temperature range 2-300 K. A moderately strong antiferromagnetic interaction between the low-spin Fe(III) (S = 1/2) and high-spin Mn(II) (S = 5/2) ions has been found for 1 leading to an S = 4 ground state (J(1) = -6.2 and J(2) = -2.7 cm(-1)), whereas a moderately strong ferromagnetic interaction between the low-spin Fe(III) (S = 1/2) and high-spin Ni(II) (S = 1) and Co(II) (S = 3/2) ions has been found for complexes 2a-3b with S = 3 (2a and 2b) and S = 4 (3a and 3b) ground spin states [J(1) = +21.4 cm(-1) and J(2) = +19.4 cm(-1) (2a); J(1) = +17.0 cm(-1) and J(2) = +12.5 cm(-1) (2b); J(1) = +5.4 cm(-1) and J(2) = +11.1 cm(-1) (3a); J(1) = +8.1 cm(-1) and J(2) = +11.0 cm(-1) (3b)] [the exchange Hamiltonian being of the type Ĥ = -J(Ŝ(i)·Ŝ(j))]. Density functional theory (DFT) calculations have been used to substantiate the nature and magnitude of the exchange magnetic coupling observed in 1-3b and also to analyze the dependence of the exchange magnetic coupling on the structural parameters of the Fe-C-N-M skeleton.

The present study refers to a variety of reduced metal-oxide core-shell hybrids, which are unique with regard to their electronic structure, their geometry, and their formation. They contain spherical {Mo(72)Fe(30)} Keplerate-type shells encapsulating Keggin-type polyoxomolybdates based on very weak interactions. Studies on the encapsulation of molybdosilicate as well as on the earlier reported molybdophosphate, coupled with the use of several physical methods for the characterization led to unprecedented results (see title). Upon standing in air at room temperature, acidified aqueous solutions obtained by dissolving sodium molybdate, iron(II) chloride, acetic acid, and molybdosilicic acid led to the precipitation of monoclinic greenish crystals (1). A rhombohedral variant (2) has also been observed. Upon drying at room temperature, compound 3 with a layer structure was obtained from 1 in a solid-state reaction based on cross-linking of the shells. The compounds 1, 2, and 3 have been characterized by a combination of methods including single-crystal X-ray crystallography, magnetic studies, as well as IR, Mossbauer, (resonance) Raman, and electronic absorption spectroscopy. In connection with detailed studies of the guest-free two-electron-reduced {Mo(72)Fe(30)}-type Keplerate (4) and of the previously reported molybdophosphate-based hybrids (including (31)P NMR spectroscopy results), it is unambiguously proved that 1, 2, and 3 contain non-reduced Keggin ion cores and reduced {Mo(72)Fe(30)}-type shells. The results are discussed in terms of redox considerations (the shell as well as the core can be reduced) including those related to the reduction of "molybdates" by Fe(II) being of interdisciplinary including catalytic interest (the Mo(VI)/Mo(V) and Fe(III)/Fe(II) couples have very close redox potentials!), while also referring to the special formation of the hybrids based on chemical Darwinism.

The synthesis, structure and magnetic properties of the first thiooxoverdazyl metal complex (Cu(hfac) 2 (Svdpy)] [hfac = (1,1,1,5,5,5)-hexafluoroacetylacetonate; Svdpy = 1,5-dimethyl-3-(2-pyridyl)-6-thiooxoverdazyl] is described. The organic radical acts as a bidentate ligand leading to a six-coordinate metal complex. The fit of the thermal variations of the magnetic susceptibility reveal a ferromagnetic intramolecular exchange interaction. This finding is confirmed and analysed by using wavefunction-based methods which indicate that the exchange interaction is governed by the substituent of the radical rather than by its heteroatom.

[(η6-Pentamethylbenzene)Mn(CO)3]+BF4− 1 and [(η6-1,2,4,5-tetramethylbenzene)Mn(CO)3]+BF4− 2 complexes were prepared and reacted with nucleophiles to provide neutral exo-substituted (η5-polymethylcyclohexadienyl)Mn(CO)3 complexes 3−6. To study the regioselectivity of the deprotonation at a “benzylic” position of (η5-methylcyclohexadienyl)Mn(CO)3 complexes, compounds 3−6 were submitted to a lithiation/electrophilic quench sequence, and functionalized complexes 9−18 were obtained in good yields and with a total regioselectivity. A second sequence gave rise to the formation of unprecedented bifunctionalized (η5-1,2,4,5-tetramethylcyclohexadienyl)Mn(CO)3 and (η5-pentamethylcyclohexadienyl)Mn(CO)3 complexes 19−22.

International audience; Results of a methodology applied for the physicochemical characterization of the layers of a coated body of a Chinchorro mummy are presented. Using scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and X-ray Diffraction (µXRD) we confirm that the plaster that covers individuals is composed of different painted layers, prepared based on clays and mineral pigments. The decorations covered by new layers of paint show an intentional act of re-painting, which is interpreted as potential rites of care for and re-signification of the dead. This raises new questions about the role played by the dead and ancestors in the rites, ceremonies and daily life of the Chinchorro society of archaic hunters, gatherers and fishermen (7,000-3,500 BP) from the coastal Atacama Desert.; Se presentan los resultados de una propuesta metodológica aplicada a la caracterización fisicoquímica de las capas pictóricas del cuerpo de una momia Chinchorro con técnica de preparación modelada. La utilización de microscopia electrónica de barrido con energía dispersiva de rayos X (MEB-EDX) y difracción de rayos X (µDRX) permite confirmar que el emplaste que recubre a los individuos se compone por diferentes capas pictóricas, preparadas a base de arcillas y pigmentos minerales, aplicadas sucesivamente. Decoraciones anteriores recubiertas por nuevas capas de pintura muestran un acto intencional de repintado, lo que se interpreta como posibles ritos de cuidado y resignificación de los muertos. A su vez abre nuevas interrogantes respecto del rol que jugaron los muertos y ancestros en los ritos, ceremonias y vida diaria de los Chinchorro, sociedad de cazadores recolectores, pescadores arcaicos (7.000- 3.500 a.p.) que habitaron la costa del desierto de Atacama.

International audience; Study of prehistoric art is playing a major role in the knowledge of human evolution. Many scientific methods are involved in this investigation including chemical analysis of pigments present on artefacts or applied to cave walls. In the past decades, the characterization of coloured materials was carried on by taking small samples. This procedure had two main disadvantages: slight but existing damage of the paintings and limitation of the number of samples. Thanks to the advanced development of portable systems, in-situ analysis of pigment in cave can be now undertaken without fear for this fragile Cultural Heritage. For the first time, a portable system combining XRD and XRF was used in an underground and archaeological environment for prehistoric rock art studies. In-situ non-destructive analysis of black prehistoric drawings and determination of their composition and crystalline structure were successfully carried out. Original results on pigments used 13,000 years ago in the cave of Rouffignac (France) were obtained showing the use of two main manganese oxides: pyrolusite and romanechite. The capabilities of the portable XRD–XRF system have been demonstrated for the characterization of pigments as well as for the analysis of rock in a cave environment. This first in-situ experiment combining X-ray diffraction and X-ray fluorescence open up new horizons and can fundamentally change our approach of rock art studies.

The coordination properties of vacant bisphosphonate derivatives of polyoxometalates, with easily tunable functions, have been explored. The preparation and crystallographic structure of their La(3+) and Zr(4+) complexes are described herein.

La utilizacion de oxidos de manganeso se evidencia en el extremo norte de Chile desde el periodo Arcaico (ca. 10.500-4.000 cal. a.p.) en tierras bajas (costa y valles) y tierras altas (precordillera y altiplano). En tierras bajas aparece en contextos de cazadores-recolectores y pescadores Chinchorro, en los procesos de momificacion artificial y en cuerpos momificados de forma natural. En tierras altas se encuentra en aleros ocupados por cazadores-recolectores terrestres altoandinos. Adicionalmente, la informacion geologica existente apunta a que las fuentes de los oxidos de manganeso se encuentran solo en sectores altoandinos. Con toda esta informacion, sumado a nuestros resultados obtenidos a partir de analisis fisico-quimicos de los pigmentos y pinturas de contextos arqueologicos se discute sobre la produccion o cadena operativa del color negro a partir del mineral de manganeso, la criptomelana. Adicionalmente, se proponen alternativas interpretativas en torno al abastecimiento y movilidad de los oxidos de manganeso desarrollados por las sociedades arcaicas de la region.

Resume En 2010, la fondation Institut de paleontologie humaine (Paris) a acquis un squelette monte de rhinoceros laineux, Coelodonta antiquitatis (Blumenbach, 1799), dont le remarquable etat de conservation a permis une etude pluridisciplinaire : analyses anatomique, biometrique, geochronologique (datations par le carbone-14 par AMS de la corne et de certains os) et biogeochimique (reconstitution de la paleoalimentation et du paleoenvironnement par la methode des isotopes du carbone et de l’azote). Une recherche sur l’origine de ce specimen et son parcours avant son acquisition a egalement ete menee. Ces differentes investigations nous ont conduits a preciser l’identification specifique du fossile siberien, son âge biologique et son sexe, ainsi que son attribution chronologique et son comportement alimentaire.

La Grotte de Rouffignac (Dordogne, France) est un site d'art paléolithique qui renferme de nombreux dessins réalisés au trait noir (mammouths, bisons, rhinocéros laineux, chevaux, bouquetins...). Bien qu'aucune datation directe n'ait été réalisée à ce jour, les œuvres graphiques de cette caverne sont en général rattachées au Magdalénien. The Cave of Rouffignac (Dordogne, France) is a Palaeolithic rock art site which contains numerous black drawings (mammoths, bisons, rhinoceros, horses, ibexes…). Although no direct dating was carried out until now, the artworks of this cave are generally connected with the Magdalenian Culture.

A new 1D coordination polymer comprised of [Mn(III)(6)O(2)(Et-sao)(6)(EtOH)(4)(H(2)O)(2)](2+) units and bithiophene dicarboxylato was synthesized by mixing EtsaoH(2) (salicylaldoxime), H(2)btda (2,2'-bithiophene-5,5'-dicarboxylic acid) and Mn(ClO(4))(2)·6H(2)O in the presence of NEt(4)OH. The crystal structure was determined and consists of Mn(6) clusters bridged by the bithiophene dicarboxylato ligands coordinated to two of the Mn(III) ions of the Mn(6) polynuclear complex. Direct current magnetic measurements show an overall ferromagnetic interaction between the Mn(III) ions within the Mn(6) cluster leading to an S = 12 ground state for the Mn(6) unit. Furthermore, this compound presents single-molecule magnet behaviour. Slow relaxation of the magnetization is observed at low temperature following a thermal activated regime with U(eff) approximately 50 K and tau(0) approximately 2.2 10(-10) s. The magnetic measurements do not show any noticeable interaction between the Mn(6) clusters through the bithiophene dicarboxylato bridges.

The synthesis of a series of six thioxo-tetrazane derivatives is reported. The crystal structures of five of these new products and the corresponding oxo-compounds (except the 4,6-dimethylpyrimidyl derivative) including two new crystal structures are also described and compared. The structural data show the importance of the substituent for the intramolecular arrangement while the heteroatom (S, O) does not play any role at this stage: the 2-pyridyl, 4,6-dimethylpyrimidyl and 8-quinolyl groups occupy a pseudo-equatorial position related to the existence of an intramolecular hydrogen bond where the substituent acts as an acceptor. 2-Hydroxyphenyl moieties occupy a pseudo-axial position related to the existence of an intramolecular hydrogen bond where the substituent acts as a donor. In the sole example where an intramolecular hydrogen bond is not present (2-imidazolyl derivatives), the preference for the pseudo-axial conformation is determined by the hyperconjugative effect. In contrast with the intramolecular arrangement, the crystal packing strongly depends on the choice of the heteroatom. It shows noticeable differences related to the variable involvement of CS and CO functions as hydrogen-bond acceptors and the occurrence of π stacking between the molecules. It thus appears that the sulfur atom of the thioxotetrazanes is always involved in hydrogen bonding whereas this is not the case for the oxygen atom of the oxotetrazane analogues. This result contrasts with the statistical treatment of the crystal structures of the Cambridge Structural Database in the urea/thiourea series and could be related to the steric hindrance imposed by the two methyl groups borne by the nitrogen atoms located in the α positions of the CX function (X = S, O).

This article presents the results of physical–chemical characterization of the layers of coating covering the bodies, faces and stuffed of four mummified human bodies and seven grave goods from the Chinchorro Archaic funerary tradition that inhabited the Atacama Desert of the far northern coast of Chile. Using Scanning Electron Microscopy with Energy-Dispersive X-Rays (SEM-EDX) and X-Ray Diffraction (μDRX), the study identified the use of different pigments including iron, manganese and copper oxides that were combined into different preparations or pictorial recipes for paste and coating bodies and faces. The results indicate that the Chinchorro, an archaic hunting, gathering and fishing society (7000- 3500 B.P.) managed a complex color technology for their mortuary practices.

A new 1D coordination polymer comprised of [MnIII6O2(Et-sao)6(EtOH)4(H2O)2]2+ units and bithiophene dicarboxylato was synthesized by mixing EtsaoH2 (salicylaldoxime), H2btda (2,2′-bithiophene-5,5′-dicarboxylic acid) and Mn(ClO4)2·6H2O in the presence of NEt4OH. The crystal structure was determined and consists of Mn6 clusters bridged by the bithiophene dicarboxylato ligands coordinated to two of the MnIII ions of the Mn6 polynuclear complex. Direct current magnetic measurements show an overall ferromagnetic interaction between the MnIII ions within the Mn6 cluster leading to an S = 12 ground state for the Mn6 unit. Furthermore, this compound presents single-molecule magnet behaviour. Slow relaxation of the magnetization is observed at low temperature following a thermal activated regime with Ueff≈ 50 K and τ0≈ 2.2 10−10 s. The magnetic measurements do not show any noticeable interaction between the Mn6 clusters through the bithiophene dicarboxylato bridges.

The self-assembly of [Fe(III){B(pz)(4)}(CN)(3)](-) and [Co(II)(bik)(2)(S)(2)](2+) affords the diamagnetic cyanide-bridged [Fe(II)(LS)Co(III)(LS)](2) molecular square which is converted into the corresponding magnetic [Fe(III)(LS)Co(II)(HS)](2) species under light irradiation at relatively low temperatures.

International audience; Rock paintings in Okuniev culture.-. Abstract.-The article is devoted to the use of paint in Okunev culture rock art in the Minusinsk Basin (Central Asia) in the second half of the 3rd millenium to the beginning of the 2nd millennium B.C. A new classification of rock painting in Okuniev culture art has now been established, based on the consideration of the technological role of paint in the creation of visual images (alone or auxiliary role) and the paint colour sometimes monochrome (red or black) and other times dichromatic. Dichromatic compositions, whose existence in Okuniev art had not been previously documented, were studied and reconstructed for the first time.Laboratory studies have shown that the main pigment used was red hematite, with one sample contains a greater proportion of ochre. In all cases, the pigment is mixed with quartz grains, which may have either a natural origin (in the case of ochre) or they were deposited in the sample on the stone surface from the surrounding subsoil. The black paint is composed of charcoal, and its application was probably carried out by rubbing a charcoal shard on the stone surface. The larger particle size of the black paint explains why is has lower resiliency than the red paint, as this particle size is not conducive to good traction with the surface of the stone. Traces of organics, which could have been used as a binder for the pigment particles, were not detected in the analysis. An important fact was established that charcoal was used for the creation of black paint, which also opens up the possibility for the direct dating of Okuniev rock art, as well as the study of different tree species used.; Résumé.-. L'article 1 est consacré à l'utilisation de la peinture dans l'art rupestre de la culture Okuniev du bassin de Minoussinsk (Asie centrale), datant de la deuxième moitié du IIIe millénaire au début du II e millénaire (av. J.-C). Il s'agit d'une nouvelle classification des peintures de l'art rupestre Okuniev, fondée sur les techniques d'utilisation des pigments (seul ou associés) durant la réalisation des iconographies et sur les couleurs choisies, parfois unique (monochrome) rouge ou noire, ou d'autre fois associées (polychrome). Les compositions bi-chromiques, dont l'existence dans l'art Okuniev est inédite, sont étudiées et reconstituées pour la première fois. L'analyse des peintures, réalisée en laboratoire, a permis d'identifier l'hématite pour la majorité des pigments de couleur rouge et de grande quantité d'ocre pour un seul échantillon. Dans tous les échantillons, le pigment était mélangé avec des grains de quartz, d'origine naturelle (cas de l'ocre), provenant de la surface des roches ou du sol. La peinture noire (deux prélèvements) se compose de charbon de bois, les dessins étant réalisés par frottement contre la surface de la roche. La recherche de traces de matière organique qui aurait pu servir de liant n'a pas été positive au cours de cette analyse. La découverte de l'utilisation du charbon de bois pour la couleur noire permet d'espérer un jour prochain la possibilité de dater l'art rupestre de la culture Okuniev mais également de mener des investigations sur les essences d'arbres choisies pour ce pigment. L'art rupestre Okuniev marqué par l'utilisation de peintures rouges et noires et par des représentations polychromes, trouve un écho dans la culture de Karakol située dans l'Altaï. La ressemblance est d'autant plus importante qu'elle concerne aussi bien les couleurs que le style des représentations. La comparaison de l'art de Karakol à celui de la première période Okuniev suggère même l'existence de deux variantes territoriales d'une seule et même tradition picturale.