Clusters heteroatoms

Heteroatom cluster addition reactions are exemplified by the following ... 

Heteroatom fullerene-type clusters — The possibility of incorporation of hetero atoms into C clusters has excited the attention of both theoreticians and experimentalists since the earliest days of fullerene chemistry, particularly in view of the known stability and ubiquity of organic heterocycles. The structural relationship between Ceo and /3-rhombohedral boron has already been alluded to (p. 142). 

Mercaptobenzothiazole with [Ru3(CO)i2l gives the cluster 41 (76TMC186, C192, 78IC2103). Two ruthenium atoms are bonded to the exocyclic sulfur site, while the third one is coordinated via the nitrogen heteroatom. 

Examples of "very tnixed"-metal cluster-assisted C-heteroatom bond formation are still rare, with both literature extant examples involving coupling of bridging phosphido ligand with a C-ligand. Phosphido, hydrido, and alky tie were assembled stereospecilically to afford PPh2(( /.v-CR=CHR) (Fig. 29),-" while an unusual... 

Heteroatom Cluster Compounds Incorporating Polyhedral Boranes as Ligands... 

The formation of boron-carbon bonds between the boron atoms of the clusters and carbon atoms of substituents has been described [51, 52]. These reactions have, however, not been used for the preparation of compounds useful for BNCT. Rather, the connection between the cluster and organic moieties via heteroatoms such as S, O, and N, has been achieved, and several compounds of interest to BNCT have been prepared by subsequent reactions on these heteroatoms. 

The heteroatoms S, O, and N can be introduced as substituents of the cluster under acidic conditions (see Scheme 2.2-19). For S and O, the reaction of the hydrochlorides of thiopyrrolidone or pyrrolidone, with the non-protonated form of the pyrrolidone as solvent, is the method used by most workers. The amino group can be introduced with hydroxylamine O-sulfonic acid. 

In comparison with the enormous number of carboranes the family of the heavier group 14 heteroborane clusters is yet very small. Most of the heteropoly-borane skeletons with Si, Ge, Sn or Pb atoms belong to the group of larger sized closo- and nido-clusters and the chemistry of these heteroboranes is essentially concentrated on the heteroatoms. 

Borane Clusters with Croup 15 and Croup 16 Heteroatoms Survey of Compounds and Structures... 

In the following section, we give a survey of the known types of heteroboranes in question and discuss the structures in terms of the Wade-Williams rules. Readers, who are interested in the synthesis of heteroatom clusters, in their skeletal transformations, or in reactions at the ligand sphere, are referred to the cited literature. conjuncto- Boranes with heteroatoms in the skeleton are not considered in this brief discussion. 

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