scholarly journals Anion and pH dependent molecular motion by a halogen bonding [2]rotaxane

2019 ◽  
Vol 55 (67) ◽  
pp. 9975-9978 ◽  
Author(s):  
Harry A. Klein ◽  
Heike Kuhn ◽  
Paul D. Beer
Keyword(s):  
Molecular Motion ◽  
Anion Recognition ◽  
Colour Change ◽  
Halogen Bonding ◽  
Chloride Anion ◽  
Naked Eye ◽  
Ph Dependent

A halogen bonding [2]rotaxane undergoes macrocycle translocation only upon both protonation and chloride anion recognition, resulting in a naked-eye detectable colour change.

A Halogen-Bonding Bis-triazolium Rotaxane for Halide-Selective Anion Recognition

2014 ◽  
Vol 21 (4) ◽  
pp. 1660-1665 ◽  
Author(s):  
Benjamin R. Mullaney ◽  
Benjamin E. Partridge ◽  
Paul D. Beer
Keyword(s):  
Anion Recognition ◽  
Halogen Bonding

Anion Recognition and Cation-Induced Molecular Motion in a Heteroditopic [2]Rotaxane

2010 ◽  
Vol 17 (3) ◽  
pp. 816-825 ◽  
Author(s):  
Alexandre V. Leontiev ◽  
Charlotte A. Jemmett ◽  
Paul D. Beer
Keyword(s):  
Molecular Motion ◽  
Anion Recognition

Novel nitro-substituted formazan derivatives: selective ratiometric and colorimetric chemosensors for fluoride anion sensing detectable by the naked eye

2020 ◽  
Vol 44 (22) ◽  
pp. 9485-9492 ◽  
Author(s):  
Gulsen Turkoglu
Keyword(s):  
Anion Recognition ◽  
Fluoride Anion ◽  
Anion Sensing ◽  
First Report ◽  
Naked Eye

This study is the first report of formazan derivatives designed as chemosensors for fluoride anion recognition.

Changing the properties of samples after extraction from wet soil: a short review

2020 ◽  
Vol 20 (4) ◽  
pp. 399-407
Author(s):  
Yuriy Vodyanitskii ◽  
Tatiana Minkina
Keyword(s):  
Colour Change ◽  
Field Measurements ◽  
Short Review ◽  
Gas Composition ◽  
Soil Suspension ◽  
Hydromorphic Soil ◽  
Hydromorphic Soils ◽  
Naked Eye ◽  
Gas Medium ◽  
Soil Changes

Laboratory-dried specimens yield distorted information about the state of hydromorphic soil. Changes in the gas medium, humidity, temperature, aggregation capacity and illumination have an irreversible impact on the dried and powdered soil specimen. Properties of the dried hydromorphic soil can be altered significantly. Most altered are (1) the colour of the hydromorphic soils, (2) the рН value, and (3) the content of mobile trace metal (TM) compounds after drying the wet soil. Colour change (browning) of the hydromorphic soil is related to the oxidation of Fe(II). In a highly ferruginous soil, the browning is rapid and visible even to the naked eye. In the weakly ferruginous gley, the colour change is invisible to the naked eye, but instrumental field measurements reveal a slow and slight yellowing of the dried gley. In dried soils, laboratory рН values determined in soil suspension differ from the values determined in soil solution at the same time. The process of drying provokes a significant decrease in the content of mobile TM compounds, resulting in the illusion of less soil contamination than the real situation during hydromorphic soil humidification. When studying hydromorphic soils, it is desirable to accomplish the maximum possible field measurements. Laboratory analyses should only be carried out for specimens stored under dark conditions since they retain the initial humidity, temperature and gas composition.

scholarly journals Comparison of Visual and Instrumental Assessment of Colour Differences on Finished Wooden Surfaces

2020 ◽  
Vol 71 (2) ◽  
pp. 201-207
Author(s):  
Matjaž Pavlič ◽  
Marko Petrič
Keyword(s):  
Colour Change ◽  
Visual Assessment ◽  
Surface Finishing ◽  
Colour Difference ◽  
Naked Eye ◽  
Instrumental Assessment ◽  
A Value ◽  
Starting Point ◽  
Measurement Results ◽  
Transparent Coating

Staining of wood with various substances and processes is an important part of surface finishing of wood. Colour differences as a result of staining and of exposure of coloured wood during its utilisation are usually evaluated by instrumental measurements. However, the measurement results can show something else compared to what our naked eye can see. Due to inhomogeneity of wood, this discrepancy can be even greater in the case of finished surfaces. The aim of our research was to evaluate distinctions between visual perception and numerically determined colour differences on differently finished wooden surfaces, to get information at which starting point the colour difference becomes visible, and to establish whether it is related to the nature of the surface. We established that the visual assessment is influenced by many factors and that there is a correlation between visual and instrumental assessments. The colour difference ΔE* of 0.5 should be considered as a value when it starts to become visible, and at the value of 2.0, observers already considered the colour difference as a different colour. It was stated that we have some tolerance in perceiving the colour change. This tolerance is more expressed in the case of transparent coating systems.

scholarly journals Superior anion induced shuttling behaviour exhibited by a halogen bonding two station rotaxane

2016 ◽  
Vol 7 (8) ◽  
pp. 5171-5180 ◽  
Author(s):  
Timothy A. Barendt ◽  
Sean W. Robinson ◽  
Paul D. Beer
Keyword(s):  
Hydrogen Bonding ◽  
Halogen Bond ◽  
Translational Motion ◽  
Anion Recognition ◽  
Halogen Bonding ◽  
Recognition Site ◽  
Naphthalene Diimide

Two bistable halogen and hydrogen bonding-naphthalene diimide [2]rotaxanes have been prepared and the system incorporating a halogen bond donor anion recognition site is demonstrated to exhibit superior anion induced translational motion of the macrocyclic wheel component relative to the hydrogen bonding analogue.

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