Pyrene-sensitized electron transport across vesicle bilayers: dependence of transport efficiency on pyrene substituents

Abstract

Endoergic electron transport across vesicle bilayers from ascorbate (Asc-) in the inner waterpool to methylviologen (MV2+) in the outer aqueous solution was driven by the irradiation of pyrene derivatives embedded in the vesicle bilayers. The initial rate of MV2+ reduction is dependent on the substituent group of the pyrenyl ring; a hydrophilic functional group linked with the pyrenyl ring by a short methylene chain acts as a sensitizer for the electron transport. Mechanistic studies using (1-pyrenyl)alkanoic acids (1a-c) as sensitizers suggest that the electron transport is mainly initiated by the reductive quenching of the singlet excited state of the pyrene by Asc- and proceeds by a mechanism involving electron exchange between the pyrenes located at the inner and outer interface across the vesicle bilayer. We designed and synthesized novel unsymmetrically substituted pyrenes having both a hydrophilic group linked by a short methylene chain and a hydrophobic long alkyl group (5a-c), which acted as excellent sensitizers for the electron transport across vesicle bilayers.

A Series of Pyrene‐Substituted Silicon Phthalocyanines as Near‐IR Sensitizers in Organic Ternary Solar Cells

“…The precursor SiPcCl 2 was synthesized according to the procedures of Lo et al and Lim et al ( Scheme 1 a) . 1‐Pyrenecaxboxlic acid, 1‐pyreneacetic acid, and 1‐pyrenebutyric acid were purchased from Sigma Aldrich and used without further purification, while 1‐pyrenepropionic acid 6 was synthesized according to the reported procedure (Scheme b) . Silicon phthalocyanines SiPc‐Py‐1, SiPc‐Py‐2, SiPc‐Py‐3, and SiPc‐Py‐4 were synthesized as described in Scheme c.…”

Optimised Synthesis of the Bacterial Magic Spot (p)ppGpp Chemosensor PyDPA

“…It is worth noting that the same reaction conditions applied to phthalate 5 only resulted in alkyne decomposition and a mixture of unidentified by‐products. Catalytic reduction of the triple bond of 9 has been described with PtO 2 (15 mol %) in THF, but we found that much cheaper Pd/C in methanol worked just as well, with a lower catalyst loading (5 mol %) and shorter reaction times (20 min); thus resulting in an overall dramatic decrease in the reaction cost.…”

“…Although classical Sonogashira conditions are described as being effective for the reaction of propargyl alcohol (8)w ith 2, [16] in our hands only copper-free conditions, with [Pd(PPh 3 ) 4 ] as ac atalyst in nBuNH 2 at reflux, gave the desired product 9 in excellent yield (94 %; Scheme 3). [17] It is worth noting that the same reaction conditions appliedt op hthalate 5 only resulted in alkyne decomposition and am ixture of unidentified by-products.C atalytic reduction of the triple bond of 9 has been described with PtO 2 (15 mol %) in THF, [18] butw ef ound that much cheaper Pd/C in methanol workedj ust as well, with a lower catalyst loading (5 mol %) and shorterr eaction times (20 min);t hus resulting in an overall dramatic decrease in the reactioncost.…”

Robust Dynamics of Synthetic Molecular Systems as a Consequence of Broken Symmetry

“…Feringa's research into nano-cars may provide one example of this, although his team's experiment was conducted using an intermittent electric current rather than continuous light waves [15]. Photo-induced ion or electron transportation across membranes [16,17] provides further instances of this phenomenon [5]. However, to attain more significant autonomous work at the multi-molecular scale, the concept of dissipative self-organization is required.…”