Parallel interpenetration

It may be noted that the statement made above—that the surface potential in the electrolyte phase does not depend on the orientation of the crystal face—is necessarily an assumption, as is the neglect of S s1- It is another example of separation of metal and electrolyte contributions to a property of the interface, which can only be done theoretically. In fact, a recent article29 has discussed the influence of the atomic structure of the metal surface for solid metals on the water dipoles of the compact layer. Different crystal faces can allow different degrees of interpenetration of species of the electrolyte and the metal surface layer. Nonuniformities in the directions parallel to the surface may be reflected in the results of capacitance measurements, as well as optical measurements. 

Two major categories of interpenetrating 2D network can be discerned - one we shall refer to as parallel interpenetration and the other as inclined interpenetration . Inclined interpenetration inevitably leads to a 3D interlocked composite, whereas in all cases but one very recent one, parallel interpenetration yields a 2D composite. 

Figure 10. Parallel interpenetrating (4,4) nets in the structure of [Cd(4-pic)2 Ag(CN)2 2] (4-pic) where 4-pic, i.e. 4-methylpyridine, is pendant and is omitted. Cd therefore is the apparently 4-connecting (actually 6-coordinate) center shown here. Each Cd is connected to four others by bridging Ag(CN)I- Circles in order of decreasing size represent Cd, Ag and CN.

Figure 11. The parallel interpenetration of (6,3) nets in the [Cu2(CN) N(CN)2 2r polyanion. Large circles represent Cu, small circles C and N.

A mode of parallel interpenetration of two (4,4) nets topologically different from that in Figure 10 is seen in [Cu(tcm)(bipy)], where bipy is 4,4 -bipyridine [11]. In this case the tern- ligands act as bent 2-connectors, as shown in Figure 12. 

Figure 14. Schematic representation of the two parallel interpenetrating (4,4) nets in [Mn43](C104)2 showing the polyrotaxane-polycate-nane associations. 6-connecting nodes are provided by 6-coordinate Mn and node-to-node connections by ligand 4.

The coordination polymer formed by the ligand M/V -p-phenylenedimethylene-bis(pyridin-4-one), 4, of composition [Mn43](C104)2 consists of two (4,4)-based nets that interpenetrate in the parallel fashion [13]. As for [Zn32](N03)2 -4.5H20, above, a second bridging ligand is present between certain Mn nodes whereby... 

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. 

Parallel Interpenetration of 2D Nets to Give a 3D Interlocked Composite... 

In the inclined mode of interpenetration any one sheet has an infinite number of inclined ones passing through it to produce an interlocked 3D composite in the manner represented in Figure 16. In contrast to parallel interpenetration, each sheet passes through an inclined one just once along a line of intersection of the two planes. All examples of inclined interpenetration known at present involve either (4,4) or (6,3) nets. 

In its geometrically most regular form, shown in Figure 21, the (10,3)-a net has cubic symmetry and angles at nodes are all 120°. 4-Fold helices run parallel to the axes. All the helices have the same handedness, making the net as a whole chiral. Wells foresaw, before real examples were known, that the (10,3)-a net is in principle capable of participating in interpenetration not only with an identical net... 

As students of the hermetic tradition we all recognise that the alchemical work takes place on many different levels -the physical work with substances, the experience and manipulation of etheric forces, the interior work on the soul, as well as the spiritual and planetary/cosmic aspects of alchemy. These different facets of the work interpenetrate and overlap each other. Indeed, in a sense, if we are to make any progress in alchemy, we must pursue the different facets concurrently, paralleling interior development with experience of the outer work. One symbol that belongs to all these different realms of this work is that of the alchemical vessel. In this article I would like to outline some ways in which we can use this symbol in our inner exercises. 

Figure 9.36 ID—>1D parallel interpenetration of hydrogen bonded strands of 4,4 -trimethylenedipyridine 9.12 and 4,4 -sulfonyldiphenol 9.13.

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