Supramolecular solid state arrays

Other supramolecular structures such as dendrimers have also been synthesized with zinc-containing porphyrins. Sixteen free base and sixteen zinc porphyrin units were added at the fifth generation of dendritic poly(L-lysine) and intramolecular fluorescence energy transfer was observed.823 Assembly of supramolecular arrays in the solid state has been achieved with the incorporation of an amide group for hydrogen bonding. Zinc meso-tetra(4-amidophenyl)porphyrin... 

Nanosized supramolecular materials have received increasing attention during the last two decades. Their properties have been surveyed for their ability to form aggregates in the solution phase, which form channel-like arrays in the solid state, and which ultimately form single channels in planar bilayer membranes. These systems therefore illustrate, in general, the convergence of supramolecular selforganization and supramolecular function. 

Zinc(II) dithiophosphates and their adducts, e.g. Zn[S2P(OR)2]2 L [R = Pr, Cy L = 4,4 -bipy, Zra ,s-l,2-6z,s(4-pyridyl)ethylene, l,2-Zw(4-pyridyl)ethane]22 and Zn[S2P(OPr )2]2(4,4 -bipy)23 are self-asssembled in the solid state through bridging ligands to form supramolecular chain-like arrays. The metal is four-coordinate tetrahedral. 

Finally, a metal- -T 6-arene interaction that generates a supramolecular onedimensional array has been reported in the solid-state structure of the (2,6-diphe-nylpyridine)gold(III) derivative [Au(CN) 2,6-NC5H3(C6H4)2-C,C, N [ [66]. Its crystal structure shows that the planes of the planar molecules are parallel, but slip-stacked via intermolecular Au- -T 6-arene contacts in which the distance between the gold atom and the centroid of the arene is 3.428 A. A representation of this structure is shown in Figure 5.35. 

These ligands exhibit interesting solid-state structures [34] but discussion of these is beyond the scope of this chapter. This and other similar ligands [35] have been used in the preparation of interesting supramolecular arrays combined with organic substrates that offer complementary donor-acceptor functions and lead to the formation of strong hydrogen bonds. 

As pointed out in Chapter 1, supramolecular chemistry comprises two broad, partially overlapping areas covering on the one hand the oligomolecular supermolecules and, on the other, the supramolecular assemblies, extended polymolecular arrays presenting a more or less well-defined microscopic organisation and macroscopic features depending on their nature (layers, films, membranes, vesicles, micelles, microemulsions, gels, mesomorphic phases, solid state species, etc.). 

V.R. Pedireddi, W. Jones, A.P. Chorlton, R. Docherty, Creation of crystalline supramolecular arrays a comparison of cocrystal formation from solution and by solid-state grinding, Chem. Commun. (1996) 987-988. 

A, while that between the pairs is 3.383(6) A. The 7r-stacked arrays of cations are linked by centrosymmetric pairs of Se(2)—N(l ) contacts, thereby generating ribbons running along the y-direction. These four-center Se—N supramolecular synthons, which are common in diselenadiazolylium salts and diselenadiazolyl radicals, are likely to dominate the solid-state structures of reduced diselenazolyl materials. 

Examples of supramolecular association as a result of intermolecular organolead-sulphur interactions are rare and compounds such as Me3PbSMe and Pl PbSPh are monomeric in the solid state463. In contrast, triphenyllead pyridine-4-thiolate, d-Pl PbSCsFLjN464, is a chain polymer as a result of intermolecular N—Pb interactions. The cyclic dithiolate 2,2-diphenyl-l,3,2-dithiaplumbolane 177465 self-assembles in the solid state via intermolecular tin-sulphur interactions into a one-dimensional polymeric array. The intramolecular Pb—S bond lengths amount to 2.52(2) and 2.49(1) A and the intermolecular Pb—S distances are 3.55(2) A. 

Molecules with silanol functions are known to form supramolecular arrays in the solid state (linear polymeric chains, 2D-sheets or layers, 3D-networks) based on intermolecular H-bonding between Si-OH groups like the one described in Scheme 4 for dialkyl-silanediol [18],... 

The well-defined geometric parameters that dictate polymerizations of diacetylenes in the solid state have led Lauher and Fowler to employ principles of supramolecular chemistry to control the reaction within co-crystals. In particular, a urea derivative has been shown to self-assemble to form a hydrogen-bonded 3-array that preorganizes complementary diacetylenes for a 1,4-photopolymerization. Through the use of a derivative with lateral carboxylic acid groups (Scheme 2.3.8(a)) and a bis (4-pyridyl)acetylene as the reactant (Scheme 2.3.8(b)), a solid-state arrangement suitable for the reaction was achieved (Fig. 2.3.11(a)) [58]. Indeed, general applic-... 

A second important focus of our work is the development of suitable analytical methods for the solid state and in solution. The physical characterization of metallo-supramolecular systems has mainly relied on crystal structure determination. Studies have also been performed on surface layers 40-42). The classical analytical methods (like FAB mass spectrometry) or most polymer methods (like light scattering, vapor pressure osmometry or membrane osmometry) can not be used. In solution, ESI mass spectrometry (43-45) and NMR (27,46) have been succesfully applied. We have explored whether MALDI-TOF mass spectrometry in the solid state (Schubert, U. S. Lehn, J.-M. Weidl, C. H. Spickermann, J. Goix, L. Rader, J. Mullen, K., unpublished data.) and sedimentation equilibrium analysis in the analytical ultracentrifuge for solutions may be employed. Grid-like cobalt coordination arrays ([2 X 2] Co(n)-Grid) were used as model systems in the analytical ultracentrifuge (47). 

In addition to the function of ordered hydrogen bonded arrays in the biological cell [42], the design of new materials is closely connected with the organised self-assembly of supramolecular structures [43]. The physical and chemical properties of molecular aggregates depend on the nature of the constituent molecules as well as on the manner in which the molecules assemble in the solid state. This is because the properties and architectural features of the supramole-... 

A large number of terms have been used to describe forms of isomerism in extended supramolecular arrays observed in the solid state. These include architectural isomerism,topological isomerism,and older terms that have specific and often well-defined meanings, in-... 

Concomitant [2 - - 2] photodimerisation reactions in the solid state from supramolecular H-bonded arrays self-assembled via mechanochemistiy... 

In the solid state dimethylgallium azide [Me2GaN3L is a supramolecular array, 84, consisting of spiral chains (Ga-N 2.051 and 2.039 A), but in solution cryoscopic measurements indicate trimeric aggregation [233],... 

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