Adamantane unit

Depending on the spatial arrangement of the adamantane units, higher polymantanes n > 4) can have several isomers and nonisomeric equivalents. There are three possible tetramantanes, all of which are isomeric. They are depicted in Fig. 2 as iso-, anti-, and skew-tetramantane. Anti- and skew-tetramantanes each possess two quaternary carbon atoms, whereas iso-tetramantane has three. 

The relative and absolute configurations of diepoxydicarbazoles involving the 2,6-dioxa-4,8-diazaadamantane system were determined in the course of a study on indole and indole alkaloids.242 Water-soluble azo, anthraquinone, and phthalocyanine dyes which are substituted by a 4-chloro-s-triazin-2-ylamino group can be quaternized with a l-aza-3-methyl-4,6,10-trioxa-adamantane unit in aqueous medium at 40 50"C.243 Dyes mixed with... 

Figure 3. The 66-a or (6,4)-a diamond net with one adamantane unit highlighted.

Figure 4. (a) Two interpenetrating adamantane units in the structure of Zn(CN)2. Circles represent Zn and connections between Zn atoms are provided by linear bridging cyanides, (b) A single cyclohexane-like Zn6(CN)6 ring catenated by six distinguishable rings. 

Figure 35. The interpenetrating pyrochlore structure in Hg2Nb207. Circles in order of decreasing size represent Hg, Nb, and O. Interpenetrating adamantane units of the [Nb206 ] net (black bonds) and the [Hg202+] net ( open bonds) are shown.

In Figures 10-13 are illustrated the stereopacking diagrams of complexes 3 5, 3 6, 4 5, and 4 6. In these cases, a super-adamantane unit may be cut out as a characteristic building block of the super-diamond architecture. The space group of the former super-structure was found to be P2 /c, which is a subgroup of that of cubic diamond, Fd im. 

Willner et al. developed a redox-active rotaxane (Figure 50) as a monolayer assembly on an Au electrode. The rotaxane comprises a CBPQT + cyclophane threaded onto a molecular string, which includes a rr-donor diiminobenzene unit stoppered by an adamantane unit. The cyclophane localizes on the diiminobenzene unit initially, and shuttling can be induced by the reduction or oxidation of the cyclophane, which can be characterized... 

Wiswesser line notation [46-48] is another important historical development in chemical notation that offered useful service in early searches for chemical compounds. More recent developments were more mathematical, based on suitable modifications of graph theoretical concepts. In the case of structurally related molecules, simple nomenclatures have been developed for benzenoid hydrocarbons by Balaban based on the concept of inner duals. In this approach, benzene rings are represented by single vertices that are connected if benzene rings have a common CC bond [26,49], Balaban and Schleyer extended the dualist graph principle to polymantane, which is bnilt from adamantane units superimposed on a diamond lattice [50,51]. 

FIGURE 2.19 3-D carbon skeleton of the diamantane C14H20 molecule, which consists of two fused adamantane units with canonical labels. 

This net is named after a rare form of carbon also called hexagonal diamond that in its turn was named after British crystal lographer Kathleen Lonsdale (1901-1971). The Ion net has the same vertex symbol as the diamond dia net, 62-62 62-62-62-62, genus 5 (dia has genus 3) and can be differentiated numerically from the dia net by the CIO value 1027 (dia has 981). By inspection one should look for the boat formed six-rings that are absent in the dia net, and for the adamantane units that are absent in the Ion net, see Figure 7.13. 

Figure 2. (a) An adamantane-like component of the diamond net showing one of the 2-fold axes, (b) View of adamantane unit looking slightly offset from the 2-fold axis. 

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