Outer-sphere interaction of (S)-asparagine and (S)-glutamine with [Co(NH3)6]3+ ion and its possible role in ligand substitution

1987 ◽  
Vol 52 (10) ◽  
pp. 2457-2459
Author(s):  
František Jursík
Keyword(s):  
Amino Acids ◽  
Transition Region ◽  
Alkaline Medium ◽  
Optical Activity ◽  
Substitution Reaction ◽  
Outer Sphere ◽  
Ligand Substitution ◽  
Cotton Effect ◽  
Negative Cotton Effect

Optical activity of the achiral cation [Co(NH3)6]3+ is induced both by (S)-AsnONa and (S)-GlnONa, as shown by a negative Cotton effect in the 1A1g → 1T1g transition region. An outer-sphere interaction by three-point attachment of the amides can explain the fact that substitution reaction of [Co(NH3)6]3+ with the mentioned amides in an alkaline medium is unusually slow as compared with other amino acids.

Linear Synthesis of {4-[(2-Alkoxy/aralkyloxy-3,5-dichlorophenyl)sulfonyl]-1-piperazinyl}(2-furyl)methanones as Possible Therapeutic Agents

2019 ◽  
Vol 41 (4) ◽  
pp. 685-685
Author(s):  
Muhammad Athar Abbasi Muhammad Athar Abbasi ◽  
Wajiha Khan Wajiha Khan ◽  
Aziz ur Rehman Aziz ur Rehman ◽  
Sabahat Zahra Siddiqui Sabahat Zahra Siddiqui ◽  
Ghulam Hussain Ghulam Hussain ◽  
...  
Keyword(s):  
Alkaline Medium ◽  
Inhibitory Activity ◽  
Substitution Reaction ◽  
Parent Compound ◽  
Ph Control ◽  
Therapeutic Agents ◽  
Lithium Hydride ◽  
Aqueous Alkaline Medium

In the present work, a series of {4-[(2-alkyloxy/aralkyloxy-3,5-dichlorophenyl)sulfonyl]-1-piperazinyl}(2-furyl)methanones was synthesized through a linear bi-step approach. The synthesis was initiated by the coupling of 2-furyl(1-piperazinyl)methanone (1) with 3,5-dichloro-2-hydroxybenzenesulfonyl chloride (2) under dynamic pH control in aqueous alkaline medium to form parent compound, {4-[(3,5-dichloro-2-hydroxyphenyl)sulfonyl]-1-piperazinyl}(2-furyl)methanone (3). Then, the O-substitution reaction on nucleophile 3 was carried out by treating it with different alkyl/aralkyl halides (4a-l) in the presence of lithium hydride (LiH) and N,N-dimethylformamide (DMF) to obtained the designed {4-[(2-alkoxy/aralkyloxy-3,5-dichlorophenyl)sulfonyl]-1-piperazinyl}(2-furyl)methanones (5a-l). These synthesized compounds were screened against α-glucosidase enzyme and some of them exhibited considerable inhibitory activity. Additionally, compounds were also evaluated for hemolytic and cytotoxic profile.

ChemInform Abstract: OPTICAL ACTIVITY OF MIXED COMPLEXES OF COPPER(II) AND AMINO ACIDS IN THE VISIBLE REGION

1976 ◽  
Vol 7 (8) ◽  
pp. no-no
Author(s):  
L. GIL ◽  
E. MORAGA ◽  
H. BOBADILLA ◽  
S. BUNEL ◽  
C. A. BUNTON
Keyword(s):  
Amino Acids ◽  
Optical Activity ◽  
Visible Region ◽  
Mixed Complexes

scholarly journals Kinetics and mechanism of formation of the complex [Ru(CN)5INH]3− through the ligand substitution reaction between the aquapentacyanoruthenate(II) anion and isoniazid

2019 ◽  
Vol 44 (3) ◽  
pp. 244-256
Author(s):  
Rupal Yadav ◽  
Radhey Mohan Naik
Keyword(s):  
Ionic Strength ◽  
Substitution Reaction ◽  
Ligand Substitution ◽  
Yellow Colour ◽  
First Order ◽  
Charge Transfer Transitions ◽  
Colour Product ◽  
Pseudo First Order ◽  
Experimental Findings ◽  
Ligand Substitution Reaction

The formation kinetics of the complex, [Ru(CN)5INH]3−, formed through the ligand substitution reaction between isoniazid (INH) and aquapentacyanoruthenate(II) ([Ru(CN)5H2O]3−), have been investigated, under pseudo first-order conditions, as a function of concentrations of [INH] and [Ru(CN)5H2O]3−, ionic strength and temperature at pH = 4.0 ± 0.02 in 0.2 M NaClO4 spectrophotometrically at 502 nm ( λmax of intense yellow colour product [Ru(CN)5INH]3−) corresponding to metal-to-ligand charge-transfer transitions, in aqueous medium. The pseudo first-order condition was maintained by taking at least 10% excess of [INH] over [Ru(CN)5H2O]3−. The stoichiometry of the reaction product was found to be 1:1 which was further supported and characterized using elemental analysis, infrared, nuclear magnetic resonance and mass spectrometric techniques. Thermodynamic and kinetic parameters have also been computed, using the Eyring equation, and the values of ΔH≠, Ea, ΔG≠ and ΔS≠ were found to be 47.3 kJ mol−1, 49.8 kJ mol−1, −8.62 kJ mol−1 and 187.6 J K−1mol−1, respectively. The reaction was found to obey first-order kinetics with respect to [INH]. It exhibited a negative salt effect on the rate upon variation of ionic strength of the medium. A tentative mechanistic scheme was proposed on the basis of experimental findings.

Solid-phase ligand substitution processes by outer-sphere anions in isomeric mixed-ligand hexamine chromium(III) complexes

1985 ◽  
Vol 30 (2) ◽  
pp. 365-375 ◽  
Author(s):  
Yu. H. Shevchenko ◽  
V. A. Logvinenko ◽  
N. I. Yashchina ◽  
E. A. Pisarev ◽  
G. V. Gavrilova
Keyword(s):  
Solid Phase ◽  
Outer Sphere ◽  
Ligand Substitution ◽  
Mixed Ligand
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