Cages tetrahedral

Walter, M. and Hakkinen, H. (2006) A hollow tetrahedral cage of hexadecagold dianion provides a robust backbone for a tuneable sub-nanometer oxidation and reduction agent via endohedral doping. Physical Chemistry Chemical Physics, 8, 5407-5411. 

Although a number of impressive chiral, supramolecular architectures were not discussed in this chapter either due to their instability in solution or their inability to encapsulate guest molecules, they should not go unmentioned and are referenced to follow up for the interested reader. Some selected examples are (i) Saalfrank and coworkers octadecametallic square box composed of 52 achiral components with molecular D2 symmetry [160] (ii) Ward and coworkers truncated, cationic tetrahedral cage [Co Lis]244 [161] that encapsulates four tetrafluoroborate counter-ions in the solid state (iii) James... 

The use of relatively straight connecting ligands enables the formation of standard polyhedra, such as tetrahedra. A well studied example of a tetrahedral cage... 

Fig. 13 Crystal structure of an [Fe4(14)6]12 tetrahedral cage, counter-ions and hydrogen atoms not shown for clarity...

Tetrahedral cages or clusters have long been known for the P4, As4, and Sb4 molecules and in more recent years have been found in polynuclear metal carbonyls such as Co4(CO)i2, Ir4(CO)12, [Tf-QHsFelCO)], RSiCo3(CO)9, Fe4(CO) 3, Re4(CO)12H4, and a number of others B4C14 is another well-known example and doubtless many more will be encountered. 

Springborg, J. Pretzmann. U. Olsen, C.E. An inert proton coordinated inside tetrahedral cage [3 ] adamanzane. 24. Synthesis of the inside monoprotonated amine 1.5.9.13-tetraazatricyclo [7.7.3.3 ] docosane. Acta Chem. Scand. 

Figure 26 An enormous chiral truncated tetrahedral cage self-assembles from 30 independent components. The naphthy-bridged 6w-pyrazolylpyridine ligand of this [Coi2Li8] + assembly is very slightly different in structure from a phenylene-bridged analog, which assembles a modest [Co4L6] tetrahedron...

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