Synthetic ion transporters in bilayer membranes

Fyles, Thomas M.; Heberle, Daniela; Straaten-Nijenhuis, Wilma F. van; Zhou, Xin

doi:10.1080/10610279508032521

Cited by 12 publications

(8 citation statements)

References 14 publications

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“…Vvrith increasing pressure above 11 GPa, a second quadiupolai inolecular phase. an oi-thorhomblc Ci?~cn (P-CO,) (Fig lA), pre~ralls (5,6) This C i~~c n molecular phase persists to at least 50 GPa (7,8), but no fui-ther k~lowledge 1s presently available of addltlonal phase tiansitlon. before eventual pressure-mduced chemical decompositioll (9).…”

Section: Pressure-induced Solid Carbonates From Molecular Co By Compmentioning

confidence: 97%

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Self-Assembly of Disk-Shaped Molecules to Coiled-Coil Aggregates with Tunable Helicity

Engelkamp

Middelbeek

Nolte

1999

Science

743

437

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A disk-shaped molecule with chiral tails is shown to form long fibers of molecular diameter and micrometer length by self-assembly in chloroform. The molecules are derived from crown ethers and contain a phthalocyanine ring. In the fibers, they have a clockwise, staggered orientation that leads to an overall right-handed helical structure. These structures, in turn, self-assemble to form coiled-coil aggregates with left-handed helicity. Addition of potassium ions to the fibers leaves their structure intact but blocks the transfer of the chirality from the tails to the cores, leading to loss of the helicity of the fibers. These tunable chiral materials have potential in optoelectronic applications and as components in sensor devices.

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Section: Pressure-induced Solid Carbonates From Molecular Co By Compmentioning

confidence: 97%

“…Such n-systeins are respoilsible for the observed conductivity of electrons and excitons in stacked phthalocyanines (6). The crown ether moieties have potential as ion coilductors ( 7 ) , and the chiral tails can induce liquid-ciystalline behavior (8).…”

mentioning

confidence: 99%

Self-Assembly of Disk-Shaped Molecules to Coiled-Coil Aggregates with Tunable Helicity

Engelkamp

Middelbeek

Nolte

1999

Science

743

437

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“…Even good macrocyclization reactions produce moderate amounts of compound and differential protection schemes required to produce functional ion channel compounds further lengthen the synthesis and diminish the yield. 25 Our own recent efforts have been directed solely to the goal of simplifying the required syntheses without compromising ion channel function, and a key to our recent progress was the decision to avoid macrocyclization reactions. 21,26 The drive towards simple syntheses inevitably draws towards self-assembly processes, and our attention eventually settled on the system reported by Fujita and co-workers of the assembly of a supramolecular square macrocycle (1) from ethylenediamine palladium(II) nitrate (2) and 4,4 0 -bipyridine (3) at room temperature in aqueous solution.…”

Section: Introductionmentioning

confidence: 99%

Long-lived and highly conducting ion channels formed by lipophilic ethylenediamine palladium(ii) complexes

Fyles

Tong

2007

New J. Chem.

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“…(iv) Several fluorescent probes have been applied to characterize the closing and reopening of pores in vesicle membranes. − Edge amphiphiles usually formed domains enclosing a water-filled ion pore. Fitting hydrophobic stoppers then interrupted the ion flow.…”

Section: Introductionmentioning

confidence: 99%

Fluorescence Quenching and Size Selective Heterodimerization of a Porphyrin Adsorbed to Gold and Embedded in Rigid Membrane Gaps

et al. 1999

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Octaanionic meso-tetra(3,5-dicarboxylatophenyl) porphyrin 1 was adsorbed to gold electrodes at pH 12 and stayed there after repeated washing with 10-2 M KOH. The fluorescence on sputtered gold surfaces amounted to 10% of the intensity observed on an organic subphase. Addition of 10-6 M aqueous solutions of the manganese(III) complexes of an isomer mixture of tetracationic β-tetraethyl-β‘-tetrakis(1-methyl-4-pyridinium)- and meso-4-(1-methyl-4-pyridinium)phenyl porphyrins 2 and 4 at pH 12 quenched the fluorescence quantitatively. Visible spectroscopy proved that the amount of porphyrin 1 on the gold surface had not changed. The octaanionic porphyrin 1 was then embedded in a membrane by self-assembly of a bolaamphiphile containing two secondary amide groups. Two hydrogen bond chains rigidify such a monolayer. The emission of porphyrin 1 remained after the self-assembly process. 1 was now localized on the bottom of a rigid membrane gap. Its fluorescence was again quantitatively quenched by the tetracationic manganese(III) porphyrinate 2, which fit in with the membrane gap. A larger manganese(III) porphyrin with a phenyl spacer between the porphyrin and methyl pyridinium rings could not enter, and no quenching was observed. The same experiment with a more fluid membrane made of octadecanethiol showed no such discriminating effect. The entrapment of 1,2-trans-cyclohexanediol within the “immobile” water volume of the membrane gap is also reported. Water-soluble compounds have thus been separated within a 2 nm3 water volume from bulk water. So far, the membrane pores with a porphyrin bottom resemble natural enzyme clefts.

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Synthetic ion transporters in bilayer membranes

Cited by 12 publications

References 14 publications

Self-Assembly of Disk-Shaped Molecules to Coiled-Coil Aggregates with Tunable Helicity

Self-Assembly of Disk-Shaped Molecules to Coiled-Coil Aggregates with Tunable Helicity

Long-lived and highly conducting ion channels formed by lipophilic ethylenediamine palladium(ii) complexes

Fluorescence Quenching and Size Selective Heterodimerization of a Porphyrin Adsorbed to Gold and Embedded in Rigid Membrane Gaps

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