Sterospecific polymerization with alkali metal organic compounds

1962 ◽  
Vol 2 (2) ◽  
pp. 105-106
Author(s):  
D. Braun ◽  
M Herner ◽  
W. Kern
Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1420
Author(s):  
Chenyang He ◽  
Liangliang Liu ◽  
Sergiy Korposh ◽  
Ricardo Correia ◽  
Stephen P. Morgan

A tip-based fibreoptic localised surface plasmon resonance (LSPR) sensor is reported for the sensing of volatile organic compounds (VOCs). The sensor is developed by coating the tip of a multi-mode optical fibre with gold nanoparticles (size: 40 nm) via a chemisorption process and further functionalisation with the HKUST-1 metal–organic framework (MOF) via a layer-by-layer process. Sensors coated with different cycles of MOFs (40, 80 and 120) corresponding to different crystallisation processes are reported. There is no measurable response to all tested volatile organic compounds (acetone, ethanol and methanol) in the sensor with 40 coating cycles. However, sensors with 80 and 120 coating cycles show a significant redshift of resonance wavelength (up to ~9 nm) to all tested volatile organic compounds as a result of an increase in the local refractive index induced by VOC capture into the HKUST-1 thin film. Sensors gradually saturate as VOC concentration increases (up to 3.41%, 4.30% and 6.18% in acetone, ethanol and methanol measurement, respectively) and show a fully reversible response when the concentration decreases. The sensor with the thickest film exhibits slightly higher sensitivity than the sensor with a thinner film. The sensitivity of the 120-cycle-coated MOF sensor is 13.7 nm/% (R2 = 0.951) with a limit of detection (LoD) of 0.005% in the measurement of acetone, 15.5 nm/% (R2 = 0.996) with an LoD of 0.003% in the measurement of ethanol and 6.7 nm/% (R2 = 0.998) with an LoD of 0.011% in the measurement of methanol. The response and recovery times were calculated as 9.35 and 3.85 min for acetone; 5.35 and 2.12 min for ethanol; and 2.39 and 1.44 min for methanol. The humidity and temperature crosstalk of 120-cycle-coated MOF was measured as 0.5 ± 0.2 nm and 0.5 ± 0.1 nm in the humidity range of 50–75% relative humidity (RH) and temperature range of 20–25 °C, respectively.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Peter C. Ho ◽  
Jin Wang ◽  
Ignacio Vargas-Baca

Abstract Species that contain bonds between hydrogen and selenium or tellurium have a characteristic high reactivity, which can be harnessed in the synthesis of valuable organic compounds. This overview includes the synthesis of dihydrides, alkali metal hydrochalcogenides, chalcogenols, chalcogenocarboxylic and chalcogenocarbamic acids, and their application in reactions of reduction, addition to unsaturated compounds, and nucleophilic substitution.


2019 ◽  
Vol 16 (2) ◽  
pp. 143-149
Author(s):  
O. V. Bashta ◽  
L. P. Pasichnyk ◽  
N. M. Voloshchuk ◽  
G. G. Repich ◽  
O. O. Zholob ◽  
...  

The aim of present paper is to study the antifungal activity of the new platinum, palladium and copper chelate complexes with different organic ligands against Fusarium strains and to determine the influence of these compounds on the germination energy and seed germination of investigated grain crops. Methods. In vitro antifungal activities of new chelate complexes were studied by the agar disk diffusion method. New complexes were tested against pathogenic Fusarium strains such as — F. culmorum 3260/4, F. verticillioides and F. sporotrichioides. The toxic effect of new complexes was evaluated according to changes in germination power and seed germination of grain crops — winter wheat, vernal barley and maize. The determination of these characteristics was carried out in accordance with the standard demands. Results. Our results revealed that palladium complex H exhibited fungicidal activity against F. culmorum 3260/4 and fungistatic activity against F. verticillioides with growth inhibition zone diameter 25 mm ad 20 mm respectively. Copper complex 2 showed a moderate fungicidal effect against F. culmorum 3260/4 strain (inhibition zone diameter 12 mm). The treatment of grain crops seeds with the H and 2 complexes demonstrated the less toxicity than standard agent — commercial fungicide tebuconazol. These complexes had also less negative influence on the germination power for all test cultures than tebuconazol. Copper complex 2 showed a noticeable growth promoting effect on studied seeds compared to seeds under conditions without treatment. Conclusions. Thus, the studied complexes can be considered as promising antifungal agents with growth regulating properties. The directional modification of the complexes to obtain the more potent derivatives will be performed.Keywords: metal-organic compounds, antifungal, growths regulation activity.


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