Compounds of Cobalt(III) With trans-6,13-Diamino-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane

1991 ◽  
Vol 44 (8) ◽  
pp. 1023 ◽  
Author(s):  
NF Curtis ◽  
A Siriwardena
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Spectroscopic Properties ◽  
Octahedral Coordination ◽  
Amino Groups ◽  
Zinc Amalgam ◽  
Primary Amino ◽  
Hydroxo Compound

Compounds are described of cobalt(III) with the macrocycle trans-6,13-diamino-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane ( diam ) of the types [Co(diam-N6)]3+, with diam in octahedral coordination, with the primary amino substituents coordinated trans; [Co(diam-N5)X]2,3+ and [Co(diamH-N5)X]3,4+, with diam in square pyramidal pentacoordination , with a ligand X,X-coordinated trans to the primary amino substituent and with the non-coordinated amino substituent neutral or monoprotonated, respectively; and trans-[Co(diamH-N4)X2]2+ and trans-[Co(diamH2-N4)X2]3+, with diam in planar tetracoordination, with trans ligands X-, and with one or both amino groups protonated , respectively. The diam and [Co(H2O)6](ClO4)2 in water exposed to the air react to sequentially form [Co( diam )]2+, trans-[{Co(diam-N5)}2(O2)]4+, trans-[Co(diam-N5)(OH)]2+ and [Co(diam-N6)]3+ cations. The μ- peroxo or hydroxo compounds can be used to prepare other N5-cations including [Co(diamH-N5)(H2O)]4+, [Co(diamH-N5) Cl ]3+ and [Co(diam-N5) Cl ]2+. [Co(diamH2-N4)]4+ formed by reduction of [Co(diam-N6]3+ with zinc amalgam in hydrochloric acid reoxidizes in air to form trans-[Co(diamH2-N4)Cl2]3+ and a [Co(diamH-N5) Cl ]2+ cation isomeric with that obtained from the hydroxo compound. The N4-tetra- and N5-penta-coordinated forms are stable in acid solution, but in base convert sequentially into the N6-hexacoordinated form in equilibrium with trans-[Co(diam-N5)(OH)]2+. Preparations, spectroscopic properties, and interconversion reactions of compounds of these cations, and some bromo, thiocyanato and acetato analogues are reported.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

Corrosion Inhibition Properties of Cinnamon Extract on Monel 400 in Hydrochloric Acid Solution

2019 ◽  
Vol 13 (6) ◽  
pp. 350
Author(s):  
Sihem Kherraf ◽  
Nesrine Ammouchi ◽  
Emna Zouaoui
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Corrosion Inhibition ◽  
Hydrochloric Acid Solution ◽  
Cinnamon Extract ◽  
Monel 400

Purification of Penicillin Amidohydrolase, an Enzyme for Semisynthetic Procedures

1992 ◽  
Vol 57 (10) ◽  
pp. 2187-2191 ◽  
Author(s):  
Jiří Jiráček ◽  
Tomislav Barth ◽  
Jiří Velek ◽  
Ivo Bláha ◽  
Jan Pospíšek ◽  
...  
Keyword(s):  
Affinity Chromatography ◽  
Amino Groups ◽  
Primary Amino

Penicillin amidohydrolase (EC 3.5.1.11.) is one of the few enzymes used successfully for deprotection of primary amino groups of semisynthetic peptides. The available material is usually contamined by endo- and exopeptidases. We managed to prepare the enzyme devoid of trypsin- and chymotrypsin-like activities using affinity chromatography with specific ligands: Gly-D-Phe-Phe-Tyr-Thr-Pro-Lys-Thr (the fF peptide) and Leu-Gly-Val-D-Arg-Arg-Gly-Phe (the rR peptide). For further purification of the enzyme affinity chromatography with N-phenylacetyl-D-tert-Leu as a ligand was used.

scholarly journals Fennel (Foeniculum Vulgare) Essential Oil as Green Corrosion Inhibitor of Carbon Steel in Hydrochloric Acid Solution

2011 ◽  
Vol 29 (2) ◽  
pp. 127-138 ◽  
Author(s):  
N Lahhit ◽  
A Bouyanzer ◽  
J-M Desjobert ◽  
B Hammouti ◽  
R Salghi ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Hydrochloric Acid ◽  
Essential Oil ◽  
Acid Solution ◽  
Corrosion Inhibitor ◽  
Hydrochloric Acid Solution ◽  
Foeniculum Vulgare ◽  
Green Corrosion Inhibitor

scholarly journals Adsorption of gold(III) and thallium(III) on .BETA.-cyclodextrin polymer from hydrochloric acid solution.

1988 ◽  
Vol 4 (6) ◽  
pp. 611-615 ◽  
Author(s):  
Hideko KOSHIMA ◽  
Hiroshi ONISHI
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Hydrochloric Acid Solution ◽  
Cyclodextrin Polymer ◽  
Beta Cyclodextrin

Azetidine derivatives as efficient corrosion inhibitor for N80 steel in hydrochloric acid solution

2015 ◽  
Vol 51 (4) ◽  
pp. 680-692 ◽  
Author(s):  
Mahendra Yadav ◽  
Dipti Sharma ◽  
Sumit Kumar
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Corrosion Inhibitor ◽  
Hydrochloric Acid Solution ◽  
N80 Steel

A 35Cl magnetic resonance study of chloride exchange on indium(III) and thallium(III) in aqueous hydrochloric acid solution

1975 ◽  
Vol 28 (9) ◽  
pp. 1901 ◽  
Author(s):  
SF Lincoln ◽  
AC Sandercock ◽  
DR Stranks
Keyword(s):  
Exchange Rate ◽  
Magnetic Resonance ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Hydrochloric Acid Solution ◽  
Magnetic Resonance Study ◽  
Aqueous Hydrochloric Acid ◽  
Chloride Exchange ◽  
Lower Limits ◽  
Aqueous Hydrochloric Acid Solution

The parameters describing chloride exchange on indium(III), determined by 35Cl N.M.R., are: k(298 K)= (8.8�0+4) x 106 s-1, ΔH? = 45.7�2.3 kJ mol-1 and ΔS? = 42�8 J mol-1 K-1; and k(298 K)= (2.0�0.1)x106 s-1, ΔH? = 37.7�1.9 kJ mol-1, and ΔS? = 3�6 J mol-1 K-1 in 10.95M and 7.00M aqueous hydrochloric acid respectively, calculated from the observed exchange rate kex4[InCl4(H2O)2-].��� For thallium(III) lower limits of kex(219 K) = 1.6 x 106 s-1 and 1.3 x 106 s-1 were obtained in 10.95M and 7.00M aqueous hydrochloric acid, respectively, where [TlCl6]3- is assumed to be the exchanging species.

scholarly journals XXIX.--THE INFLUENCE OF ANTISEPTICS ON THE DIGESTION OF BLOOD FIBRIN BY PEPSIN IN A HYDROCHLORIC ACID SOLUTION.

1897 ◽  
Vol 19 (11) ◽  
pp. 889-894 ◽  
Author(s):  
Charles F. Mabery ◽  
Leo. Goldsmith
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Hydrochloric Acid Solution
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