Metal cages

Manual sampling should be carried out by grounded personnel, preferably using grounded metal equipment such as a metal sample thief bonded to the tank via metal cord. A satisfactory alternative is to place one or more glass sample bottles in a grounded metal cage (5-S.4.2). 

If you use ball-float level indicators, compare the size of the balls with those of the branches on the top of the vessel. If a loose ball could lodge in one of the branches, protect the branch with a metal cage, or use another type of level indicator. 

In addition to analogs of known C-based structures, transition metals offer novel bonding possibilities having no known precedents in main-group chemistry. As a variation on the cubane-like cage motif of Fig. 4.26(c) built from tetravalent osmium, we can envision construction of the analogous naked metal cage compound Irg... 

With the animal on the cart, the metal cage is struck with the blunt probe. The normal animal should exhibit a marked but short-duration response, in which case the space on the scoring sheet should be left blank. If present, a plus sign should be entered. 

In the field of carbonyl clusters it is not rare to find compounds in which atoms such as C, N and P become trapped in interstitial or semi-interstitial positions inside the metal cage. We will briefly consider this type of compound in order of increasing encapsulation of the interstitial atom. 

In the dianion [Fe6(CO)i6C]2-, the carbide atom is completely encapsulated in the octahedral metal cage. This dianion (86 valence electrons) does not exhibit any redox process with characteristics of chemical reversibility.ld... 

A completely different arrangement of the six metal atoms is present in the phosphide monoanion [Os6(CO)i8P]. In fact, Figure 49 shows that the phosphorus atom is completely encapsulated in a trigonal-prismatic metal cage. 

Caging Identifled females are housed individually in composite plastic and metal cages in accordance with the latest European... 

Figure 10.27 The structure of [Cd12(10.20)18](BF4)24 showing (a) polyhedral metal cage and the four encapsulated BF4 anions (b) view down one of the Cd6 pseudohexagonai faces, emphasising the cyclic helical array of ligands and the presence of an anion in the centre of the face (reproduced with permission from [22] 2006 American Chemical Society).

Encapsulation of N2 into a Sm2 Li4 metallic cage was found following the reaction sequence expressed in Eq. (4) [67]. A green Sm(II) compound is most likely part of the formal reduction of N2 to N2 . Table 1 summarizes some structurally characterized complexes with relevance to this subject. 

The probable existence of an interstitial H atom in a molecular (i.e., non-poly-meric) complex was first suggested in a paper by Eady, Johnson, Lewis and coworkers on [HRu6(CO)18] 249). In the X-ray study of this anion, the H atom was not directly located, but was presumed to be in the center of the metal cage on the basis of the near-perfect octahedral symmetry of the cluster. There were no discernible distortions of the cluster or its ligands which might have indicated an alternative placement of the H atom. 

The nearest La-C distance, 2.55(8) A (ionic radius of La(III) 1.15 A), is slightly larger than the nearest Sc-C distance, 2.53(8) A(ionic radius of Sc(III) 0.81 A), of Sc C82, which results in a weaker metal-cage interaction for La C82. In fact, the IR/Raman spectroscopic studies [31,32] on metallofullerenes by metal-cage vibrational mode measurements indicated that the La-cage vibration is much smaller in energy than those observed in other M C82 (M=Y, Sc, Tm)-type metallofullerenes. 

Electrochemical interconversion of homo- and heteronuclear gold cluster compounds remains an area that has received scant attention, despite the potential for changing the electron count and hence the metal cage geometries of these clusters by electrochemical methods. The electrochemical redox reactions of [Pt(AuPPh3)8]2+ have been studied, using pulse, differential pulse, and cyclic voltammetric techniques (124, 242) and two reversible, one-electron reduction steps have been... 

Summary of Bond Lengths and Metal Cage Geometries for Au, Heteronuclear Cluster Compounds Containing p.2-AuPR3 Fragments... 

Fig. 19. The metal cage geometries of (a) [(PhMe2P)3ReH2(AuPPh3)3] and (b) (PhMe2P) iReH3( AuPPh3 ) 1 ]".

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