Quantitative structure-property relationships in the series of diazonium cations, intermediate products in the synthesis of analytical forms and dyes

Pankratov, A. N.

doi:10.1007/s10809-005-0038-5

Cited by 3 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this case, the regioselectivity of azo coupling is described by such a reactivity index as the electron density of the frontier (highest occupied) molecular orbital (HOMO). This is supported by the occurrence of a correlation between the reduction potentials of aryldiazonium cations and their electron affinities [16,17]. Our calculated electron density of the frontier orbital demonstrates that azo coupling at carbon in position 4 is most probable.…”

Section: Methodsmentioning

confidence: 53%

“…Therefore, they can hardly be described at a high level of theory using ab initio or DFT methods. On the other hand, we have found that the MNDO, AM1, and PM3 methods correctly reproduce the most important thermodynamic and molecular characteristics ( [16,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45], etc.) and the electronegativity, inductive, and mesomeric parameters of atomic groups [16,46,47] in…”

Section: Resultsmentioning

confidence: 99%

“…Earlier, we found numerous predictive quantitative structure-property relationships in a series of aryldiazonium cations [16,17].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Analytical Azo Coupling Reactions: A Quantum-Chemical Consideration

Pankratov

2005

J Anal Chem

Self Cite

View full text Add to dashboard Cite

The nitrite ion is a priority environmental toxicant and a precursor of N-nitrosamines, which are carcinogenic and mutagenic agents [1,2]. It interacts with oxyhemoglobin in blood to form methemoglobin, which disturbs cell respiration, and, therefore, the vital functions of the entire organism [3,4]. Nitrites are added to meat foods to improve vendibility. The analytical determination of nitrites and N-nitrosamines in foodstuff and other samples is a topical problem. The simplicity, availability, and satisfactory metrological characteristics of photometry make it one of the most suitable methods for solving this problem [5,6]. The most important photometric reactions for nitrites and N -nitrosamines are the diazotization of primary aromatic amines and the subsequent azo coupling reaction [5,6].In photometric analysis, the following processes in which or N -nitrosamines participate are used: (1) the self-coupling of 1-aminonaphthalene ( I ) through the diazotization of I followed by the coupling of the resulting naphthalene-1-diazonium cation ( II ) with I [5-8] and (2) the analytical Griess reaction involving the diazotization of 4-aminobenzenesulfonic (sulfanilic) acid followed by the azo coupling of the resulting 4-sulfobenzenediazonium with amine I [5,6,9].In an aqueous solution, the former of the processes mentioned above occurs to only a small extent and the product precipitates [7,8]. However, the yield of the analytical form and the stability of the analytical signal over time improve dramatically if the reaction is performed in microreactors [10], such as anionic surfactant (sodium dodecyl sulfate) micelles [7,8]. On the contrary, the Griess reaction is successfully performed in an aqueous medium [5,6], whereas anionic surfactant micelles only slightly enhance the analytical signal NO 2 -(increase the absorbance of the solution of the analytical form) and stabilize it over time [9].Note that the stability of an analytical signal and the thermodynamic stability of molecular systems discussed below are different concepts. The former is characterized by the time in which the maximum intensity of the analytical signal remains virtually constant, whereas the latter is characterized by the enthalpy and the free energy of formation of a certain molecule.In the diazotization-azo coupling tandem, the azo coupling reaction is crucial, because its products are the sources of the analytical signal in the photometric determination of nitrite and N -nitrosamines.According to [11], the self-coupling product of 1-aminonaphthalene I is 4-amino-1,1'-azonaphthalene resulting from the interaction of naphthalene-1-diazonium cation II with I at the 4-position of the amine molecule. At the same time, the possibility is discussed [11] for the formation of 1,1'-diazoaminonaphthalene (triazene) upon the electrophilic attack of the nitrogen atom in molecule I by cation II . The author of [11] reports nothing concerning the detection of 1-amino-2,1'-azonaphthalene (the result of coupling at position 2 of molecule I ).At the same tim...

show abstract

Section: Methodsmentioning

confidence: 53%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Analytical Azo Coupling Reactions: A Quantum-Chemical Consideration

Pankratov

2005

J Anal Chem

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this case, the entropy is frequently identical in the series of isomers of compounds with similar structures while its change is almost constant in analogous reactions involving related compounds with close molecular geometries [20,[26][27][28][29][30][31][32][33].…”

Section: The Symmetrical Hydrogen Bond In [Pd(h 2 O) 3 (H 3 O)] 3+mentioning

confidence: 99%

Ligand Exchange in Pd(II)-NaCl-H2O and Pd(II)-HCl-H2O Systems: Quantum-Chemical Consideration

2005

Self Cite

View full text Add to dashboard Cite

The Pd-containing compounds exhibit the biological activity. The variety of the biological properties of the Pd ions and of another platinum-group metals is determined by the chemical and stereochemical properties of coordination compounds of these metals with the biologically active ligands (DNA, amino acids, peptides, etc.) and, in particular, by the structure of the metal-ligand coordination site (fragment or functional group of a biological system) [1]. The Pd(II) complexes with organic ligands are considered to be promising in the production of medicines [2].While studying reactions of the Pd 2+ ion with bioligands, one should take into consideration its interaction with inorganic compounds contained in liquid media of a living organism. It is not improbable that inorganic ligands (H 2 O , Cl -, etc.) can compete with the biologically active ligands for the metal ion and thus reduce toxicity of the latter ion. On the other hand, binding of the metal cation with inorganic ligands can decrease the efficiency of medicines prepared from compounds of this metal. The Pd(II) complexes are known to be bonded by the DNA molecules and to violate ordinary course of the replication process (transcription and translation) [1]. The Pd ( II )-NaCl -H 2 O and Pd ( II )-HCl -H 2 O systems can be used to model the behavior of the Pd(II) compounds in biological liquids. For instance, a 0.86% (0.147 M) solution of NaCl can be used as a model of blood plasma, while a 0.1 M solution of HCl, as that of a gastric juice [3]. The aim of this work was to study the reactions of exchange of the H 2 O and H 3 O + ligands for Cl -in the chloride and hydrogen chloride solutions of Pd(II). EXPERIMENTAL Potassium tetrachloropalladate(II) was synthesized as described in [4] from metallic Pd and Pd ë l 2 . The K 2 [ PdCl 4 ] (0.03067 M) and NaCl (0.1 M) solutions were prepared from the precisely weighed samples; a 0.1 M solution of HCl was prepared from a reagent with fixed concentration.The kinetic studies were carried out using spectrophotometric method. The electronic absorption spectra of the reaction mixtures were recorded on a UV VIS SPECORD spectrophotometer. The working solution of K 2 [ PdCl 4 ] with a concentration of 8.496 × 10 -5 mol/l was prepared by dilution. The initial solution of K 2 [ PdCl 4 ] (3.610 ml) and the solution of 0.1 M NaCl or HCl (20 µ l) were pored into a cell (1 cm) with the aid of a dispenser.The quantum-chemical calculations were performed by ZINDO/1 [5], PM3 [6], and RHF/STO-6G(d) [7] methods with the HyperChem 1 program package and full optimization using the Polak-Ribiere algorithm [8]. The gradient rate did not exceed 0.02 kcal/(mol Å).Abstract -The behavior of potassium tetrachloropalladate(II) in media simulating biological liquids is studied. The rate of aquation in aqueous NaCl solutions is shown to be higher than the rate at which the Cl -ligand enters the inner coordination sphere of the Pd atom. In HCl solutions, the formation of the Pd chloro complexes predominates due to protonation of water molec...

show abstract

Theoretical Analysis of Structure and Reactivity as a Tool for the Interpretation and Prediction of the Properties of Analytical Reagents and Forms

Pankratov

2022

J Anal Chem

View full text Add to dashboard Cite

Quantitative structure-property relationships in the series of diazonium cations, intermediate products in the synthesis of analytical forms and dyes

Cited by 3 publications

References 29 publications

Analytical Azo Coupling Reactions: A Quantum-Chemical Consideration

Analytical Azo Coupling Reactions: A Quantum-Chemical Consideration

Ligand Exchange in Pd(II)-NaCl-H2O and Pd(II)-HCl-H2O Systems: Quantum-Chemical Consideration

Theoretical Analysis of Structure and Reactivity as a Tool for the Interpretation and Prediction of the Properties of Analytical Reagents and Forms

Contact Info

Product

Resources

About