We report new hybrid organic-inorganic materials, based on macrocyclic receptors 1-3 self-organized in tubular superstructures prepared by sol-gel process. Fourier transform infrared (FTIR) and NMR spectroscopic analyses demonstrate that the self-organization by hydrogen bonding of organogel superstructures of 2 and 3 were preserved in the hybrid materials throughout the sol-gel process. The molecular arrangement of heteroditopic receptors defines a particularly attractive functional transport device for both cation (tubular macrocycles) and anion (sandwich-urea) directional-diffusion transport mechanism in the hybrid membrane material. This system has been employed successfully to design a solid dense membrane, functioning as an ion-powered adenosine triphosphate (ATP(2)(-)) pump, and illustrates how a self-organized hybrid material performs interesting and potentially useful functions.
This paper describes the controlled self-selection and quantitative parallel amplification of the homonuclear grid architectures derived from the same ligand 1 of different conformational geometries and Cu+ and Ag+ metal ions of different coordination behavior and ionic size.
In this paper we report an extended series of 2,6-(iminoarene)pyridine-type ZnII complexes [(Lii)2Zn]II, which were surveyed for their ability to self-exchange both their ligands and their aromatic arms and to form different homoduplex and heteroduplex complexes in solution. The self-sorting of heteroduplex complexes is likely to be the result of geometric constraints. Whereas the imine-exchange process occurs quantitatively in 1:1 mixtures of [(Lii)2Zn]II complexes, the octahedral coordination process around the metal ion defines spatial-frustrated exchanges that involve the selective formation of heterocomplexes of two, by two different substituents; the bulkiest ones (pyrene in principle) specifically interact with the pseudoterpyridine core, sterically hindering the least bulky ones, which are intermolecularly stacked with similar ligands of neighboring molecules. Such a self-sorting process defined by the specific self-constitution of the ligands exchanging their aromatic substituents is self-optimized by a specific control over their spatial orientation around a metal center within the complex. They ultimately show an improved charge-transfer energy function by virtue of the dynamic amplification of self-optimized heteroduplex architectures. These systems therefore illustrate the convergence of the combinatorial self-sorting of the dynamic combinatorial libraries (DCLs) strategy and the constitutional self-optimized function.
New silver (I) coordination polymers has been successfully designed and synthesized using heteroditopic ureidopyridine ligands 1 and 2 via a combination of coordinations bonds, hydrogen bonding, and pi-pi stacking interactions. This study shows an example of the orientation of the pyridine nitrogen relative to the urea moiety (4-substituted, 1, or 3-substituted, 2), used to control the packing of resulting crystalline coordination polymers. The ureidopyridine ligands present some flexibility because of the conformational rotation around the central urea moiety. The co-complexation of the silver(I) cation by two pyridine moieties and of the PF(6)(-) counteranion by the urea moiety results in the formation of discrete [1(2)Ag](+)PF(6)(-), (3) and [2(2)Ag](+)PF(6)(-), (4) complexes presenting restricted rotation around the central urea functionality. The geometrical information contained in the structures of ligands 1 and 2 and the heteroditopic complexation of silver hexafluorophosphate are fully exploited in an independent manner resulting in the emergence of quasi-rigidly preorganized linear and angular building blocks of 3 and 4, respectively. Additional pi-pi stacking contacts involving interactions between the pi-donor benzene and the pi-acceptor pyridine systems reinforce and direct the self-assembly of the above-described combined structural motifs in the solid state. Accordingly, linear and tubular arrays of pi-pi stacked architectures are generated in the solid state by synergistic and sequential metal ion complexation, hydrogen bonding, and pi-pi stacking interactions.
Aluminum (III) meso-tetraphenylporphyrins axially bonded to phosphinate anions have been synthesized and characterized by NMR and UV-visible spectroscopy, single-crystal X-ray diffraction, and FAB+ mass spectrometry. According to the solvent and the size of the anion, these compounds are able to self-assemble in two different manners.
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