A halogen-bonding foldamer molecular film for selective reagentless anion sensing in water

The first redox-active halogen bonding anion receptors display larger electrochemical voltammetric responses to halide binding compared to their hydrogen bonding analogues.

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Enhanced Voltammetric Anion Sensing at Halogen and Hydrogen Bonding Ferrocenyl SAMs

10.26434/chemrxiv.13218107.v1 ◽

2020 ◽

Author(s):

Robert Hein ◽

Xiaoxiong Li ◽

Paul D. Beer ◽

Jason J Davis

Keyword(s):

Signal Transduction ◽

Hydrogen Bonding ◽

Real Life ◽

Halogen Bonding ◽

Self Assembled Monolayers ◽

Similar Response ◽

Binding Motifs ◽

Anion Sensing ◽

Redox Active ◽

Assembled Monolayers

Halogen bonding mediated electrochemical anion sensing has very recently been established as a potent platform for the selective and sensitive detection of anions, although the principles that govern binding and subsequent signal transduction remain poorly understood. Herein we address this challenge by providing a comprehensive study of novel redox-active halogen bonding (XB) and hydrogen bonding (HB) ferrocene-isophthalamide-(iodo)triazole receptors in solution and at self-assembled monolayers (SAMs). Under diffusive conditions the sensory performance of the XB sensor was significantly superior. In molecular films the XB and HB binding motifs both display a notably enhanced, but similar, response to specific anions. Importantly, the enhanced response of these films is rationalised by a consideration of the (interfacial) dielectric microenvironment. These effects, and the resolved relationship between anion binding and signal transduction, underpin an improved fundamental understanding of anion sensing at redox-active interfaces which will benefit not just the development of more potent, real-life relevant sensors, but also new tools to study host-guest interactions at interfaces.

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Halogen bonding Strapped Porphyrin BODIPY Rotaxanes for Dual Optical and Electrochemical Anion Sensing

Chemistry - A European Journal ◽

10.1002/chem.202102493 ◽

2021 ◽

Author(s):

Yuen Cheong Tse ◽

Robert Hein ◽

Edward J. Mitchell ◽

Zongyao Zhang ◽

Paul D. Beer

Keyword(s):

Halogen Bonding ◽

Anion Sensing

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Enhanced Voltammetric Anion Sensing at Halogen and Hydrogen Bonding Ferrocenyl SAMs

10.26434/chemrxiv.13218107 ◽

2020 ◽

Author(s):

Robert Hein ◽

Xiaoxiong Li ◽

Paul D. Beer ◽

Jason J Davis

Keyword(s):

Signal Transduction ◽

Hydrogen Bonding ◽

Real Life ◽

Halogen Bonding ◽

Self Assembled Monolayers ◽

Similar Response ◽

Binding Motifs ◽

Anion Sensing ◽

Redox Active ◽

Assembled Monolayers

Halogen bonding mediated electrochemical anion sensing has very recently been established as a potent platform for the selective and sensitive detection of anions, although the principles that govern binding and subsequent signal transduction remain poorly understood. Herein we address this challenge by providing a comprehensive study of novel redox-active halogen bonding (XB) and hydrogen bonding (HB) ferrocene-isophthalamide-(iodo)triazole receptors in solution and at self-assembled monolayers (SAMs). Under diffusive conditions the sensory performance of the XB sensor was significantly superior. In molecular films the XB and HB binding motifs both display a notably enhanced, but similar, response to specific anions. Importantly, the enhanced response of these films is rationalised by a consideration of the (interfacial) dielectric microenvironment. These effects, and the resolved relationship between anion binding and signal transduction, underpin an improved fundamental understanding of anion sensing at redox-active interfaces which will benefit not just the development of more potent, real-life relevant sensors, but also new tools to study host-guest interactions at interfaces.

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Selective perrhenate recognition in pure water by halogen bonding and hydrogen bonding alpha-cyclodextrin based receptors

Chemical Communications ◽

10.1039/c7cc01605k ◽

2017 ◽

Vol 53 (27) ◽

pp. 3866-3869 ◽

Cited By ~ 28

Author(s):

Stuart P. Cornes ◽

Mark R. Sambrook ◽

Paul D. Beer

Keyword(s):

Hydrogen Bond ◽

Hydrogen Bonding ◽

Pure Water ◽

Aqueous Media ◽

Halogen Bonding ◽

Anion Receptors ◽

Hydrogen Bond Donor

Alpha-cyclodextrin based anion receptors containing halogen and hydrogen bond donor motifs display selective association of perrhenate in neutral aqueous media.

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Decoration of specific sites on freeze-fractured membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081565 ◽

1978 ◽

Vol 36 (2) ◽

pp. 140-141

Author(s):

H. Gross ◽

H. Moor

Keyword(s):

Pure Water ◽

Freeze Fracture ◽

Chemical Properties ◽

Surface Forces ◽

Sulfate Pentahydrate ◽

Copper Sulfate Pentahydrate ◽

Physico Chemical ◽

Water Of Hydration ◽

Small Container ◽

Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072873 ◽

1973 ◽

Vol 31 ◽

pp. 486-487

Author(s):

Mihir Parikh

Keyword(s):

Electron Microscope ◽

High Resolution ◽

Cross Sections ◽

Resolving Power ◽

Peak Intensity ◽

Molecular Film ◽

Resolution Electron ◽

Dissociation Cross Section ◽

High Resolution Electron Microscope ◽

The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

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