Rate of lactamization of benzylstrychnine in acid solution

1984 ◽  
Vol 62 (1) ◽  
pp. 144-146 ◽  
Author(s):  
John T. Edward ◽  
Sin Cheong Wong ◽  
Robert A. McClelland
Keyword(s):  
Aqueous Solution ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Acid Concentration ◽  
Amino Group ◽  
Cage Structure ◽  
Basic Formula

The rate of lactamization of benzylstrychnine in aqueous solution at 25 °C increases with acid concentration up to 5–10% sulfuric acid, and thereafter decreases. The maximum can be explained by taking account of the extent of protonation of the aromatic amino group with increasing acid concentration. This amino group is unusually weakly basic [Formula: see text], perhaps because it is locked in an extremely rigid cage structure which opposes the rehybridization of N which must take place when it is protonated.

Fundamental Measurements of the Friction on an Atomically-Flat Terrace of Au(100) in Sulfuric Acid Solution under Potential Control Using Electrochemical Atomic Force Microscope

2006 ◽  
Vol 512 ◽  
pp. 395-398
Author(s):  
Nobumitsu Hirai ◽  
Tatsuya Tooyama ◽  
Toshihiro Tanaka
Keyword(s):  
Aqueous Solution ◽  
Sulfuric Acid ◽  
Silicon Nitride ◽  
Acid Solution ◽  
Atomic Force Microscope ◽  
Friction Force ◽  
Potential Range ◽  
Potential Control ◽  
Atomic Force ◽  
Atomically Flat

Potential dependence of the friction force between an atomically-flat terrace of Au(100) single crystal and a tip attached to a silicon nitride cantilever of electrochemical atomic force microscope (EC-AFM) have been investigated qualitatively in 0.05 M H2SO4 aqueous solution. It is found that the friction force gains when the potential increases in the potential range between −400 mV and 400 mV vs Hg/Hg2SO4 electrode.

scholarly journals Corrosion Behavior of AA 1100 Anodized in Gallic-Sulfuric Acid Solution

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 405
Author(s):  
Marlon L. Mopon ◽  
Jayson S. Garcia ◽  
Dexter M. Manguerra ◽  
Cyril John C. Narisma
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Gallic Acid ◽  
Acid Concentration ◽  
Sulfuric Acid Solution ◽  
Current Density ◽  
Electrochemical Impedance ◽  
Anodized Aluminum ◽  
The Common

Sulfuric acid anodization is one of the common methods used to improve corrosion resistance of aluminum alloys. Organic acids can be added to the sulfuric acid electrolyte in order to improve the properties of the anodized aluminum produced. In this study, the use of gallic acid as an additive to the sulfuric acid anodization of AA1100 was explored. The effect of varying anodization current density and gallic acid concentration on the properties of anodized aluminum samples was observed using electrochemical impedance spectroscopy, linear polarization, and scanning electron microscopy. It was observed that the corrosion resistance of samples anodized in gallic-sulfuric acid solution at 10 mA·cm−2 is lower than samples anodized in sulfuric acid. It was also observed that higher anodization current density can lead to lower corrosion resistances for aluminum samples anodized in gallic-sulfuric acid solution. However, samples anodized at 5 mA·cm−2 and at a gallic acid concentration of 5 g·L−1 showed better corrosion performance than the samples anodized in sulfuric acid only. This suggests that the use of low amounts of gallic acid as an additive for sulfuric acid anodization can lead to better corrosion resistances for anodized aluminum.

scholarly journals The change in the absorption spectrum of cobalt chloride in aqueous hydrochloric acid solution with change of temperature

1936 ◽  
Vol 155 (884) ◽  
pp. 33-41 ◽  
Author(s):  
Owen Rhys Howell ◽  
Albert Jackson ◽  
Eric Keightley Rideal
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Constant Temperature ◽  
Acid Concentration ◽  
Hydrochloric Acid Solution ◽  
Cobalt Chloride ◽  
Cobalt Atom ◽  
Aqueous Hydrochloric Acid Solution

The change in the absorption spectrum of cobalt chloride in aqueous solution with increasing concentration of hydrochloric acid at constant temperature (20° C) has already been investigated.* It was shown that with increasing concentration of acid up to 5N HCl, no blue constituent was formed. The cobalt atom, therefore, retains its six grouping over this range. The effect of increasing acid concentration is to replace two molecules of water by two atoms of chlorine: [Co(H 2 O) 6 ] → [Co(H 2 O) 4 Cl 2 ].

scholarly journals Responses Of Kemiri Sunan (Reutealis trisperma) Seeds Germination To Chemical Scarification Atvarious Submersion Time In Sulfuric Acid (H2so4)

2018 ◽  
Vol 18 (2) ◽  
pp. 123
Author(s):  
Ahmad Deni Ismail ◽  
Duryat Duryat
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Experimental Method ◽  
Seed Dormancy ◽  
Acid Concentration ◽  
Germination Rate ◽  
Skin Thickness ◽  
H2so4 Solution ◽  
Effective Time ◽  
Seeds Germination

The duration of submersion and the level of acid concentration which are the decisive factors to succed the chemical scarification. The duration of submersion should be adjusted to the level of seed skin thickness, the level of acid concentration and the type of acid used. This study aimed to analyze the inmersion effect of kemiri sunan seeds in sulfuric acid solution to break the seed dormancy and to get the most effective time of submersion in order to break the dormancy of kemiri sunan seed. The experiment was conducted in the greenhouse for 2 months (62 days). The randomized complete design was employed as experimental method. There were 4 treament tested, i.e : (1) control (without immersion in H2SO4 solution); (2) immersion in H2SO4 solution for 10 minutes; (3) immersion in H2SO4 solution for 20 minutes and (4) immersion in H2SO4 solution for 30 minutes. The results of research showed that control gave the best results in term of the percentage of germination (G), mean daily gremination (MDG), and germination rate (GR).

Dissolution Rate of Flat Plate Limestone in Agitated Sulfuric Acid Solution

2014 ◽  
Vol 617 ◽  
pp. 10-13
Author(s):  
Daiki Tanaka ◽  
Takashi Ito ◽  
Shoji Taniguchi ◽  
Tadaaki Mizoguchi
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Flat Plate ◽  
Dissolution Rate ◽  
Surface Area ◽  
Acid Concentration ◽  
Sulfuric Acid Solution ◽  
Chemical Species ◽  
Dissolution Rates ◽  
Agitated Vessel

In this study, a flat plate limestone of which surface area was accurately defined was dissolved into acid in an agitated vessel. Dissolution rates of limestone were measured under various agitation speeds, temperatures and acid concentrations. As a result, it was found that the rates were controlled by the diffusion of particular chemical species depending on acid concentration.

scholarly journals RESPON PERKECAMBAHAN BENIH KEMIRI SUNAN (Reutealis trisperma) TERHADAP SKARIFIKASI KIMIA DENGAN ASAM SULFAT (H2SO4) PADA BERBAGAI LAMA WAKTU PERENDAMAN

2018 ◽  
Vol 5 (1) ◽  
pp. 77-82
Author(s):  
Ahmad Deni Ismail ◽  
Duryat Duryat
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Experimental Method ◽  
Seed Dormancy ◽  
Acid Concentration ◽  
Sulfuric Acid Solution ◽  
Germination Rate ◽  
Skin Thickness ◽  
H2so4 Solution ◽  
Effective Time

The duration of submersion and the level of acid concentration which are the decisive factors to succed the chemical scarification. The duration of submersion should be adjusted to the level of seed skin thickness, the level of acid concentration and the type of acid used. This study aimed to analyze the inmersion effect of kemiri sunan seeds in sulfuric acid solution to break the seed dormancy and to get the most effective time of submersion in order to break the dormancy of kemiri sunan seed. The experiment was conducted in the greenhouse for 2 months (62 days). The randomized complete design was employed as experimental method. There were 4 treament tested, i.e : (1) control (without immersion in H2SO4 solution); (2) immersion in H2SO4 solution for 10 minutes; (3) immersion in H2SO4 solution for 20 minutes and (4) immersion in H2SO4 solution for 30 minutes. The results of research showed that control gave the best results in term of the percentage of germination (G), mean daily gremination (MDG), and germination rate (GR)

scholarly journals Continuos Operation of Chromium (VI) Recovery from Sulfuric Acid Solution by Liquid Surfactant Membrane.

1991 ◽  
Vol 17 (6) ◽  
pp. 1104-1109 ◽  
Author(s):  
Yasushige Mori ◽  
Shingo Hibin ◽  
Hideyuki Uemae ◽  
Masataka Tanigaki ◽  
Wataru Eguchi
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Chromium Vi
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