On the Viscosity of the Suspensions

Stoyanov, Ventseslav; Kotsilkova, Rumiana; Ivanov, Yatchko

doi:10.1007/978-3-642-51062-5_293

Cited by 6 publications

(19 citation statements)

References 1 publication

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“…These penta-atomic ligands exist in a thiol thione equilibrium [2]. However, it has been established that the thione form dominates in the solid state of these complexes [3,4]. We have studied extensively the interaction of metal ions with Imt and its derivatives [5].…”

Section: Introductionmentioning

confidence: 99%

Solid state NMR study of 1,3imidazolidine‐2‐thione, 1,3‐imidazolidine‐2‐selenone and some of their N‐substituted derivatives

Wazeer

Isab

El-Rayyes

2004

Journal of Spectroscopy

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Solid‒state NMR spectra were recorded for 1,3-imidazolidine-2-thione, 1,3-imidazolidine-2-selenone and some of their N-substituted derivatives. Spinning side-bands of thione and selenone carbons were analysed to yield chemical shift anisotropies for these carbons. The NMR spectrum of imidazolidine-2-thione (Imt) showed some evidence for the presence of thiol tautomer. Molecular computations were carried out for Imt and its N-methyl derivative to yield relative energies of various tautomers.

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Section: Introductionmentioning

confidence: 99%

Solid state NMR study of 1,3imidazolidine‐2‐thione, 1,3‐imidazolidine‐2‐selenone and some of their N‐substituted derivatives

Wazeer

Isab

El-Rayyes

2004

Journal of Spectroscopy

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“…The chemistry of mercaptopyrimidines that incorporate both S and N atoms in their structure is rich because these compounds can coordinate as monodentate ligands and more frequently as polydentate ligands either to a single metal center, acting as a chelating ligand, , or to several metal centers as a bridging ligand . These compounds exhibit tautomeric equilibrium between the thiol (>C−SH) and thione (>CS) as a consequence of the highly mobile protons that they possess (Figure ). − The predominant form largely depends on the state and conditions of the molecule. Thus, from X-ray diffraction, it has been demonstrated that 2-mercaptopyridine exhibits a predominant thione form in the solid state, although it can also develop dimeric structures through hydrogen bridges. − However, in liquid phase, there are several additional factors involved in the shift of tautomeric equilibrium.…”

Section: Introductionmentioning

confidence: 99%

“…These compounds exhibit tautomeric equilibrium between the thiol (>C−SH) and thione (>CS) as a consequence of the highly mobile protons that they possess (Figure ). − The predominant form largely depends on the state and conditions of the molecule. Thus, from X-ray diffraction, it has been demonstrated that 2-mercaptopyridine exhibits a predominant thione form in the solid state, although it can also develop dimeric structures through hydrogen bridges. − However, in liquid phase, there are several additional factors involved in the shift of tautomeric equilibrium. Among these, the solvent, temperature, pH, and concentration remain prominent .…”

Section: Introductionmentioning

confidence: 99%

The Usefulness of Density Functional Theory To Describe the Tautomeric Equilibrium of 4,6-Dimethyl-2-mercaptopyrimidine in Solution

et al. 2003

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The tautomeric forms of 4,6-dimethyl-2-mercaptopyrimidine in solution were examined. Experimental support for the existence of the tautomeric forms of this molecule was provided by infrared (FTIR), ultraviolet (UV), and nuclear magnetic resonance (NMR) techniques. Density functional theory (DFT) calculations allowed us to elucidate these molecular structures. The vibrational and electronic spectra, as well as the 1H and 13C chemical shifts, were satisfactorily described by DFT theoretical calculations. The potential of the DFT methodology was confirmed by prediction of a band at 2706 cm-1, associated with the stretching vibration of −SH group, which did not appear in the experimental spectrum because it was overshadowed by the symmetric and antisymmetric vibration modes of −CH3 groups. The existence of the tautomeric thiol−thione equilibrium of 4,6-dimethyl-2-mercaptopyrimidine with the thione structure dominating in polar solvents (CH3OH and DMSO-d 6) and the thiol structure in apolar media (cyclohexane) has been demonstrated.

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“…The difference was between one and two percent -very, very close. 46 Thus, while opinion polls may provide obvious benefits to the political parties in their general campaigning strategies and their political marketing, their usage for these purposes is often a source of significant controversy. Two of the enduring features of opinion polls in Bulgaria in both communist and postcommunist times, is that they are widely perceived by political elites, parties and citizens alike as manipulative, and that they are treated with scepticism.…”

Section: Polls and Manipulation Of The Political Process In Postcommumentioning

confidence: 99%

Opinion polls, Political Elites and Party Competition in Post-Communist Bulgaria

Henn¹

2001

Journal of Communist Studies and Transition Politics

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This article examines the role of opinion polls in East European countries, and assesses the impact that they have had on the general processes of political democratisation there since the collapse of communism.Certainly, opinion polls have taken a high-profile role in political affairs in these countries over the course of the last decade. Policy-makers, politicians and political parties made much use of polls in the early years of democratic transition, although for various reasons they were received with significant scepticism by each of these users and by citizens alike. This article compares recent research with earlier studies on the use of polls by political elites in countries seeking to consolidate democracy. From recent in-depth interviews conducted with national politicians in Bulgaria, I draw upon a number of examples to examine the ways in which political parties and elites use opinion polls, and their intentions for doing so.When George Gallup first pioneered the use of opinion polling in the USA, he did so with the intention that it would serve to enhance and extend democratic processes and practices by providing a channel through which citizens could participate in political affairs.1 He advocated a 'populist' notion of government, in which voters would have a significant input into decisionmaking. He claimed that opinion polls could provide a useful means through which this might be achieved, by objectively measuring the views of voters, and then communicating these to elected

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On the Viscosity of the Suspensions

Cited by 6 publications

References 1 publication

Solid state NMR study of 1,3imidazolidine‐2‐thione, 1,3‐imidazolidine‐2‐selenone and some of their N‐substituted derivatives

Solid state NMR study of 1,3imidazolidine‐2‐thione, 1,3‐imidazolidine‐2‐selenone and some of their N‐substituted derivatives

The Usefulness of Density Functional Theory To Describe the Tautomeric Equilibrium of 4,6-Dimethyl-2-mercaptopyrimidine in Solution

Opinion polls, Political Elites and Party Competition in Post-Communist Bulgaria

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