Normal adamantane structure

Structure compounds characterized by structures which are related to zinc blende or wurtzite as substitution and/or vacancy variants (for details, see Parth, 1990). As example for a normal adamantane structure we shall present in Rgure 1 the zinc blende structure and, as example for a defect adamantane structure, the Cdlr Se4 structure, a vacancy and substitution variant of zinc blende. 

In this class of binary compounds, a new tetragonal form of boron sulfide B2S3 prepared by high-pressure synthesis is noteworthy. Remarkably, instead of a simple structure related to that of normal ambient pressure form of B2 S3, it contains two kinds of supertetrahedra built up from 20 and 34 adamantane-type superclusters to form an elaborate three-dimensional framework (Figure 4) These supertetrahedra are linked to each other in a unique way forming an interpenetrating zinc-blende-type structure. This compound is a wide band-gap semiconductor with an energy gap of 3.7 eV. 

Examples for normal valence compounds (VEC/ = 8) with normal and detect tetrahedral structures. There are known many nonnal valence compounds with normal eind defect tetrahedral structure. A subgroup of this family is formed by the adamantane... 

Figure 12 Pairs of adamantane cavities from separate networks in the structure of /S-Cu(dca)(bpee) showing (a) normal interpenetration and (b) abnormal interpenetration.

Figure 11 Interpenetration in diamond networks (a) the two interpenetrating nets in [M(CN)2], M = Zn, Cd (b) the normal mode of interpenetration of two adamantane cavities (c) interpenetration of ten diamond nets (d) unusual interpenetration topology of adamantane cavities in the structure of 3-[Cu(dca)(bpe)] ...

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