Supramolecular chains

Rawashdeh-Omary, M.A., Pietroni, B.R. and Staples, R.J. (2000) Supramolecular chain assemblies formed by interaction of a B molecular acid complex of mercury with B-Base trinuclear gold complexes. Journal of the American Chemical Society, 122, 11264. 

Hydrogen-Bonded Supramolecular Chain and Sheet Formation by Coordinated Guanidine Derivatives... 

Hubberstey P, Suksangpanya U (2004) Hydrogen-Bonded Supramolecular Chain and Sheet Formation by Coordinated Guranidine Derivatives 111 33-83 Hupp JT (2006) Rhenium-Linked Multiporphyrin Assemblies Synthesis and Properties 121 145-165... 

Bimetallic biconnective bridging can also be symmetric or can display a variable degree of unsymmetry (Scheme 4). This coordination mode occurs in dinuclear complexes and in supramolecular chain-like arrays. When a metal-metal bond is present five-membered rings are formed. 

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. 

A plethora of polynuclear copper(I) complexes with bi-, tri-, and tetracon-necting dithiophosphato ligands have been discovered. These include cyclic dimers, [CuS2P(OEt)2 PPh3]2,43 tetrahedral Cu4[S2P(OPr )2]4,44 prismatic Cu6 S2P(OR)2 6, cubane Cu8(p8-E )[S2P(OEt)2]6 (E = S, Se),45 (also known for silver)46 and [Cu8 S2P(OPr )6(p8-X)][PF6] (X = Cl, Br).47 A supramolecular chain-like array of cubane units interconnected through iodine bridges was found in Cu8(S)[S2P(OEt)2]6(p-I) x.48... 

The tin(II) derivative Sn[S2P(OPh)2]2 is a dimeric supermolecule formed through intermolecular Sn- S secondary bonds and Sn-7i-aryl interactions.57 Lead(II) dithiophosphates, Pb[S2P(OR)2]2, e.g. R = Me,58 Pr" and Cy,59 all form supramolecular chain-like arrays. The ligands are unsymmetrically bridging and form Pb- S secondary bonds. 

Organotellurium(II) derivatives, ArTeS2P(OR)2 (Ar = 4-MeOC6H4 or 4-EtOC6H4, R = Me or Et Ar = mesityl, R = Pr7) are supramolecular chain-like compounds, self-assembled through Te- S secondary bonds and bridging... 

In organogermanium dithiophosphinates the ligand is monodentate, whereas in heavier metal compounds M -S secondary bonds may result in supramolecular self-assembly. Examples are monomeric Ph3GeS(S)PR2 (R = Me, Ph),165 and Me2Sn(S2PR2)2 (R = Me,166 Et167), supramolecular chain-like... 

Keywords Hydrogen bonding Supramolecular chains Supramolecular sheets Coordination Guanidine... 

Supramolecular chain scission differs further from covalent chain scission, because supramolecular recombination is typically the predominant fate of a ruptured chain anthropomorphically speaking, the supramolecular moieties are, by their very nature, predisposed to reassociation rather than alternative reaction pathways. This predisposition is not intrinsic to the products of covalent bond mpture, which might lead either to high-energy intermediates with nonspecific reactivity or to species that require catalyst or elevated temperature to recombine. The... 

In addition to the chiral interactions of enantiomers, interactions of dissimilar chiral species are fundamentally important. As described above, adenine becomes chiral upon adsorption and forms homochiral dimer chains on Cu(110). These chains are tilted 19.5° with respect to the [001] surface direction. This tilt makes the sites right next to an enantiomorphous supramolecular chain chiral Consequently, the interactions of inherently chiral molecules with both chain types are energetically nonequivalent. This... 

Fig. 26 The assembly of a perylene imide dye with a chiral melamine derivative to give chiral supramolecular chains...

Hannah, K.C., and Armitage, B.A. "DNA-templated assembly of helical cyanine dye aggregates a supramolecular chain polymerization". Acc. Chem. Res. 37, 845-853 (2004). 

With a different design, where chirahty is directly built in the hydrogen bond pattern (Fig. 22), Aida et al. have demonstrated that it is possible to enforce a homochiral supramolecular polymerization [141]. In this case, a mixture of L and D monomers exclusively forms supramolecular chains of polyL and polyD homopolymers instead of copolymers. 

A direct information derived from this analysis is that very large equilibrium constants are required if long supramolecular chains are sought. For instance, at a concentration of Co = 10 molL a degree of polymerization of 100 is only possible if the equilibrium constant is fC = 10 LmoC ... 

The examples discussed above refer to finite assemblies or conjugates with linear macromolecules. Based on the pioneering work by Jean Marie Lehn a number of approaches have been developed in which secondary bonds are employed to build up chain molecules. Different supramolecular chain polymers, made up from hydrogen-... 

Figure 3.9.2 Supramolecular chain-like arrays with a flattened step-ladder topology in 2. CjHj mediated by Sn.., 7t interactions. Note that the toluene molecule Is disordered about a center of inversion so that the methyl groups have 50% site occupancy factors only...

In the crystal structure of (2,6-di-t-butyI-4-methyIphenoxy) bis(trimethylsilyl)amine-tin(ll) (13), a two-coordinate tin atom is found, defined by an NO donor set. In the crystal structure, Sn... itt interactions are formed on either side of the molecule leading to the formation of a zig-zag supramolecular chain that is propagated by crystallographic glide symmetry, as shown in Figure 3.9.8. 

Figure 3.9.8 A zig-zag supramolecular chain mediated by Sn... n interactions in the structure of 13...

Figure 3.9.9 Supramolecular chains mediated by bifurcated C-H... O interactions in the structure of 14...

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