Nets, interpenetrating three-dimensional

We know of only two examples of parallel 2D interpenetration involving nets other than (6,3) and (4,4). One is Hittorf s phosphorus, in which two 82-10 nets, composed entirely of phosphorus atoms, interpenetrate [15], The other example, considered in the next section, differs from all the other parallel interpenetrating cases in that the composite formed is a three-dimensional interlocked structure. 

In the layered misfit structures each layer set A and B can be described in terms of three basic translations, i.e. by its own component lattice. [The existence of the third vector is contingent upon a strict sequence in the layer stacking. If this is absent, the two three-dimensional subcells/lattices will, in the following discussion, be replaced by two two-dimensional subcells, i.e. by submeshes (nets) built only on the intralayer vectors.] In normal layered structures the unit cells of A and B are commensurate, i.e. their unit vectors are commensurable and the periodicity of the entire structure may be described in terms of a single unit cell. In contrast, we deal with those less-frequent cases in which this is not so at least one of the basic periodicities of A and of B are incommensurate. Then the component unit cell of set A has at least one intralayer unit cell parameter which is not commensurable with the corresponding parameter of set B. Such structures have two incommensurate, interpenetrating, component lattices and can be defined as composite) layered structures with two incommensurate component unit cells. Intermediate cases, in which the nodes of the two component lattices coincide at relatively large... 

Although all of the examples shown above contain only one type of individual polymer in each, it is possible for interpenetrating networks to form using different nets, although this does not occur as frequently. The nets also do not have to have the same topology - it is possible for a one-dimensional net and a two-dimensional net to become interpenetrated, resulting in a three-dimensional... 

Carlucci, L., Ciani, G Proseq)io, D., and Sironi, A., I-, 2- and 3-dimensional polymeric frames in the coordination chemistry of AgBf with pyrazine. The first example of three interpenetrating 3-dimensional triconnected nets, J. Am. Chem. Soc., 117, 4562-4569 (1995). 

Abrahams, B. F., Batten, S. R., Hamit, H., Hoskins, B. F., and Robson, R., A Wellsian three-dimensional racemate eight interpenetrating, enantiomorphic (10,3)-a nets, four right- and four left-handed, Chem. Commun., 1313-1314 (1996). 

In his very first paper on three dimensional nets Wells also derives a net he calls simply net 10 [10]. Probably, since it is a trinodal net, it docs not appear in any of his subsequent books, [21,39,40] and its next appearance in the literature seems to be the report of a five fold interpenetrated hydrogen bonded net in [Co(l biim)2(ll2biim)]i(p 7ra-OOCC6n4COOl 1)2-112O in 2004 [41]. It has vertex symbols 4-122-122,4-12s-126, 124 126-126, and has already been shown in Figure 1.14, Wells model of this net is shown in Figure 6.37... 

Porosity may be generated, for instance, either by using awkwardly shaped molecules like 425 or by creating a net with large cages or channels (avoiding interpenetration)due to hydrogen bonds or coordination. In this way three-(3D) or two-dimensional (2D) nets are created which can host smaller molecules. Few... 

According to the concepts introduced in Fig. 1.3.10 we can have three types of interpenetrating nets based on the dimensionality (ID, 2D and 3D). 

---