Diamond network

Figure 7 3D super-tetrahedral H-bonded architectures of 1 1 complexes between linear dialcohols and linear diamines, (a) Super-diamond network with a super-adamantane type building block, (b) Super-wurtzite network with combined super-iceane and super-bicyclo [2.2.2]octane-type building blocks [28],... 

Imagine a network model of the diamond structure (Fig. 1.17(e)), blue lattice), constructed from rubber tubes. Now inflate the network, swelling the hollow tubes. The resulting structure is a curved continuous network, enclosing the tunnels in the diamond network. If the inflation procedure is continued, the surface closes up around a complementary diamond network. The D-surface is the "half-way point" during the procedure. 

Figure 1.17 (e) Computer image of a surface produced by partial inflations of a diamond network (blue). The "outside" of the surface wraps around a complementary (red) diamond lattice. Picture courtesy of David Anderson. 

Figure 1. Topological transition from a diamond network (left) to polyhedral homoatomic clusters (right). Some bonds between the tetravalent atoms break by adding electrons (middle). The formation of progressively more and more lone pairs eventually results in discrete cluster anions (right).

A system of tetrahedral co-ordinates has been proposed as a convenient means for handling geometrical problems concerned with systems of cyclohexane rings in the usual all-chair conformation. The idealized structures of such molecules correspond to fragments of a diamond network. Applications envisaged include descriptions of the fit of substrates to enzymes and the discussion of c.d. and n.m.r. features in terms of patterns of bonding. 

Figure 1 Crystal structures of (a) hexane, (b) body-centered cubic adamantane and (c) 1,3,5,7-tetracarboxyadamantane. Only one of the diamond networks is shown for (c)...

Trioxotetrafluoroditelluric(iv) acid, H2Te203p4, has been synthesized in HF solution. Its structure is characterized by Te20aF4 groups linked by hydrogen bonds to form a very distorted diamond network. ... 

Although the occurrence of interpenetration can be a nuisance when seeking to construct highly porous materials, there are situations where the presence of multiple networks is of value. The compound Cu(dcnqi>2 and its derivatives contain seven interpenetrating diamond networks. These networks interpenetrate such that infinite stacks of dcnqi ligands are created, which are responsible for the metal-like electrical conductivity observed for these compounds. Interpenetration has also led to the creation of structures with completely sealed-off, solvent-filled... 

By far and away, the most commonly observed form of interpenetration is the formation of multiple diamond networks. The classic examples are the structures of... 

This is just one illustration of abnormal interpenetration of diamond networks a small number of other examples, with different interpenetration topologies to j8-Cu(dca)(bpee), have also been reported. Interpenetration of other 4-connected topologies has also been... 

This is the case of the light elements of the group IVA C, Si, Ge. For these atoms, the accomplishment of the electronic configuration of maximum stability (octet) in the conditions of minimum inter-electronic repulsion, the hybridization state sp is imposed by the formation of four eovalent cr-bonds oriented on the hybrids lobs, i.e., tetrahedral, so that each atom has CN=4. The crystalline network formed by this kind of identical atoms is a covalent network having in the stmctural nodes/points of the lattice the atomic cores with the directed external electronic clouds. The preeminent example is the diamond network. Figure 4.27 (Chiriac-Putz-Chiriac, 2005). 

The elementary eell of the diamond network is a cubic cell with centered laces where half of the tetrahedral interstices are alternatively oceupied. 

It can be eonsidered that the diamond network results by the overlap of two eompact eubie networks, so that the comer of the elementary eell of the seeond network to be placed at 1/3 of the height... 

OTDD) strueture. In addition, two (symmetric and shifted) OTDD phases and a lamellar phase have been observed in the same simulations. The two OTDD phases are conceivable by shifting one diamond network against the other diamond network. 

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)] ...

Finally, the structure of (Me2NH2)i 75[InL]j 75 (DMF)i2(H20)io, H4L = biphenyl-3,3, 5,5 -tetra(phenyl-4-carboxylic acid) shows the peculiar property of partial interpenetration. The structure is nominally composed of two interpenetrating diamond networks however, whereas one net is fully occupied, the second net is not only equally disordered over two positions (which is unusual in itselO, but the total occupancy of these two positions is only ca. 75%. 

Finally, the map in Fig. 2 outlines the 3D networks, and a prominent member is, of course, the diamond lattice given by the Wells point symbol 6 , which is translated [17] into the Schlafli symbol (6, 4). By examination of Fig. 2, one can see that the diamond network, given the Schlafli symbol (6,4), is situated just across the borderline from the 2-dimensional honeycomb tessellation given by (6, 3) in the map. One member of the diamond network topology, is in a cubic symmetry space group of... 

Thus in the diamond network, which corresponds to the Platonic (integer) topology of the Platonic polyhedra, one can readily trace the uniform 6-gon, puckered circuitry of the network connected together by all 4-con-nected, tetrahedral vertices. Diamond s topology classifies the network as a regular, Platonic structure-type. 

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