This study concerns the formation of complexes with actinides at oxidation state +IV, from Th to Am, through a lacunary heteropolyanion ligand P(2)W(17)O(61)(10-). The preparation of original single crystals of complexes with 1:2 stoichiometry provided structural data through single-crystal X-ray diffraction for the entire An(IV) series. An(IV) atoms in these complexes have a coordination number of 8, and their coordination polyhedron is a distorted square antiprism. The data were used to compute a mean (An-O) interatomic distance for each actinide. When the interatomic distance is plotted versus the inverse ionic radius of these tetravalent actinides, it appears that the simple electrostatic model is not suitable for Am(IV) and Pu(IV), although this trend must be confirmed by further investigation with other examples from the An(IV) series.

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The first complex of a transuranium element (tetravalent plutonium) with nucleotide (deoxycytidinemonophosphate, dCMP) was synthesized and structurally characterized. The crystal structure of [Pu(4)(NO(3))(8)(HdCMP)(4)(H(2)O)(8)](NO(3))(4).2H(2)O consists of complex cations [Pu(4)(NO(3))(8)(HdCMP)(4)(H(2)O)(8)](4+), NO(3)(-) anions, and water molecules. There are two crystallographically independent Pu atoms in the structure, both having similar surroundings. Each of the Pu atoms is coordinated by three O atoms of phosphate groups belonging to three different (HdCMP)(-) anions, two bidentate nitrate anions, and two water molecules. The crystal structure is confirmed by IR and UV/vis/near-IR spectroscopic data.

The geochemistry of Hercynian tin-bearing granitoid massifs of the Krugne hory Mts. (Erzgebirge), Slavkovsk~ les Forest (Kaiserwald) and Smr6iny (eastern Fichtelgebirge) is compared by statistical processing of 270 analyses including a wide spectrum of major and trace elements. Seven different types of granites are distinguished. Out of these, five types represent the successive differentiation of the largest massif of NW Bohemia: the Karlovy Vary (Karlsbad) massif. This comprises strongly differentiated peraluminous granites evolving towards extreme Li-Rb-Cs-F-and Sn-enrichment in the youngest members, which are albite-topaz-zinwaldite "lithium" granites. The sixth and seventh types are different from the former by their location in the eastern Krugne hory and tectonic setting, and they display geochemical features of anorogenic granites: they are metaluminous albite-zinwaldite granites with marked enrichment of Nb, Y, and HREE in addition to Li, Rb, Cs, F and Sn, indicating contamination by sub-crustal material. Sn-W mineralizations, including flat peri-contact greisen bodies, steep greisen veins and tourmalinized phyllites, are all intimately associated with the most strongly differentiated granites -the Li-granite and the Cinovec-granite respectively.The Krugne hory rots. (Erzgebirge) and Slavkovsk) les Forest [Kaiserwald] form the classical central European mining district of tin (and tungsten) from greisen deposits in granite massifs of Hercynian age. These massifs are strongly differentiated into several successive intrusive phases. For this reason they are perfectly suited for studies of the relationship of granite evolution and Sn-W mineralization.Until today the area most attractive to geologists has been the largest granite massif of the area: the Karlovy Vary (Karlsbad) massif. Here, two major granite types were differentiated more than one hundred years ago (Laube 1876): the older, unmineralized "mountain granite" (Gebirgsgranit), nowadays often termed the "older intrusive complex" (330-320 Ma), and the younger, orebearing "Krugn6 hory granite" (Erzgebirgsgranit) now classified as the "younger intrusive complex" (305 295 Ma, ages after Tischendorf et al. 1989). Transitional granites connecting the two main types, were discovered in the Slavkovsky les Forest by Fiala (1968). Previous investigations of granite differentiation in NW Bohemia were mainly based on petrographically distinguished granite types (Lange et al. 1972;Baumann et al. 1974; ~temprok 1987;Tischendorf et al. 1989). There is a certain deficiency in this aproach as the granites of NW Bohemia are mineralogically relatively monotonous, but texturally very diversified. Due to this reason, an objective classification of the evolutionary phases, including a regional parallelization of the different massif s, was practically impossible so we have selected chemical data as a more objective way of evaluating the evolution of these granites. This is not only a theoretical problem, but also extremely important in order to improve the understandi...

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