Microscale metal preparation

The preparation of polysiloxane-V2 via microscale metal vapor-matrix isolation2 as well as gram, synthetic-scale rotary solution reactor3 techniques is described. Consideration of the two different-scale processes reflects both the initial preparation of the molecule and demonstrates the utility of a combined, complementary matrix-/macrosynthetic approach.4... 

P. L. 1958. The microscale preparation and micrometallurgy of plutonium metal. J. Inorg. Nucl. Chem. 5, 182-189. 

Actinide (An) metals are prepared by reduction or thermal dissociation of their com-pounds The metallothermic reduction of halides is still in use, especially for microscale preparations. In this procedure, anhydrous actinide haUdes, in general fluorides, are exposed to the vapour of alkaline or alkaUne earth metals, e.g. 

The latest developments in the preparation of anhydrous actinide halides and their reduction to metals at the microscale have been reviewed by Haire ... 

Similarly, the design of macroscale vapor synthesis reactions in liquids can benefit from adaptations of the techniques of cryogenic matrix isolation for studies in fluids.(33,34) For example, a significant development in the field of VS has been the discovery by Klabunde and co-workers(35) of "solvated" metal atoms for use in the preparation of uni-and bimetallic supported catalysts. It is worth examining the subject of solvated atoms in a little detail to reveal something about them and to introduce the microscale VS technique in thin, quiescent liquid films. 

Microscale (matrix isolated only) metal atom-olefin codepositions yield unstable TT-olefin-metal complexes that can be investigated by matrix isolation spectroscopy. By varying the concentrations of alkene and metal in the inert gas (at 10-50K), mono-, bisand tris-olefin-metal complexes can be observed. Table 1 lists ethylene and tetrafluoro-ethylene complexes prepared for Co, Ni and P(ji-3.io.ii.i2 nd If the... 

In most instances, the first solid materials of the actinides that were studied were oxides, not only because the oxides of electropositive metallic elements are primary compounds, but also because oxides may have been the easiest compound to prepare, especially on the microscale. 

Transition-metal complex of n bowls have attracted much attention [12, 34, 35]. Controlled positioning of metal centers inside the bowls is expected to provide a direct route to the inclusion complexes of fiillerenes and nanotubes. On the other hand, the coordination of metal centers to the outside of the bowls should permit applications in the field of surface activation and functionalization of fiiUerenes and nanotubes. To date, some n bowl (mainly corannulene or its derivatives) complexes with several coordination modes have been synthesized [12, 34, 35]. In addition to the conventional liquid phase synthesis, a microscale gas-phase coordination method was introduced [36] to prepare and/or jj -binding complexes, which is based on co-deposition of volatile complementary building units such as Rh2(02CCF3)4, Ru2(02C(3,5-CF3)2C H3)2(C0)5, and Ru2(02CCF3)2(C0)4 under reduced pressure. 

The first attempt to prepare californium metal was reported in 1969 [67]. Subsequently, several additional attempts have been made to prepare and study this metal [68-72]. The relatively high volatility of californium metal has made its preparation and study on the microscale more difficult than the first three transplutonium metals. The possibility that the metal may exist in two different metallic valence states has made it an interesting candidate for study, but it has also complicated the full understanding of californium s metallic state. 

Transplutonium tris(cyclopentadienyls) can be prepared on a microscale by the reaction of molten bis(cyclopentadienyl)beryllium with the corresponding metal chlorides [34-40] ... 

This area of chemistry is a development into the macroscale of matrix isolation spectroscopy as practiced in the 1960 s on the microscale [53]. Recent research with a catalytic emphasis owes its origin largely to the work of Klabunde [5A] and Ozin [55]. In the former approach, rather ill-defined materials may be obtained by the co-condensation of resistively heated metals with the vapours of organic ligands at 77 K followed by slow warm-up and contacting with a support material. Refinement of the experimental techniques has allowed the possibility of preparing the organometallic derivatives in a cleaner, more controlled manner from metal atom-solution reactions at 173 K rather than CO-condensation at 77 K. Such product solutions may be... 

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