Predicting ion rearrangement reactions — The energetics of the internal SN2 reaction in gas-phase proton-bound molecular pairs

2005 ◽  
Vol 83 (11) ◽  
pp. 1864-1870 ◽  
Author(s):  
Julie AD Grabowy ◽  
Paul M Mayer
Keyword(s):  
Key Words ◽  
Gas Phase ◽  
Proton Affinity ◽  
Intermediate Complex ◽  
Isomerization Reaction ◽  
Base System ◽  
Alkyl Groups ◽  
Rearrangement Reaction ◽  
Metastable Ions ◽  
The Difference

A common rearrangement reaction for gas-phase proton-bound molecular pairs corresponds to an internal SN2 reaction that results in the loss of a small neutral molecule. For pairs (RCN)(ROH)H+, the energies of the two transition states (TSa and TSb) and the intermediate complex (IC) in the isomerization reaction (relative to the proton-bound pair, in kJ mol–1) can be estimated using the following relationships: E(TSa) = 87 – 9(n) – 0.33(ΔPA), E(IC) = 83 – 9(n) – 0.33(ΔPA), and E(TSb) = 107 – 9(n) – 0.10(ΔPA), where 87, 83, and 107 kJ mol–1 are the values for (CH3CN)(CH3OH)H+. Here, n is the number of stablizing alkyl groups on the central SN2 carbon and ΔPA is the difference between the proton affinity of the migrating moiety and that for the base system (in this case, CH3CN). For the analogous pairs (ROH)(R′OH)H+, only the first value in each expression is different (98, 94, and 121 kJ mol–1, respectively, calculated for (CH3OH)2H+).Key words: proton-bound molecular pairs, isomerization, internal SN2 reaction, energetics, metastable ions.

Explaining the magnetism of gold

2017 ◽  
Author(s):  
Robson de Farias
Keyword(s):  
Gas Phase ◽  
Computational Study ◽  
Formation Enthalpy ◽  
Gold Atom ◽  
Orbital Energy ◽  
Knudsen Effusion ◽  
Energy Diagram ◽  
Unpaired Electrons ◽  
The Difference ◽  
Good Agreement

<p>In the present work, a computational study is performed in order to clarify the possible magnetic nature of gold. For such purpose, gas phase Au<sub>2</sub> (zero charge) is modelled, in order to calculate its gas phase formation enthalpy. The calculated values were compared with the experimental value obtained by means of Knudsen effusion mass spectrometric studies [5]. Based on the obtained formation enthalpy values for Au<sub>2</sub>, the compound with two unpaired electrons is the most probable one. The calculated ionization energy of modelled Au<sub>2</sub> with two unpaired electrons is 8.94 eV and with zero unpaired electrons, 11.42 eV. The difference (11.42-8.94 = 2.48 eV = 239.29 kJmol<sup>-1</sup>), is in very good agreement with the experimental value of 226.2 ± 0.5 kJmol<sup>-1</sup> to the Au-Au bond<sup>7</sup>. So, as expected, in the specie with none unpaired electrons, the two 6s<sup>1</sup> (one of each gold atom) are paired, forming a chemical bond with bond order 1. On the other hand, in Au<sub>2</sub> with two unpaired electrons, the s-d hybridization prevails, because the relativistic contributions. A molecular orbital energy diagram for gas phase Au<sub>2</sub> is proposed, explaining its paramagnetism (and, by extension, the paramagnetism of gold clusters and nanoparticles).</p>

Molecular orbital structures of sulfones

1982 ◽  
Vol 60 (6) ◽  
pp. 730-734 ◽  
Author(s):  
Russell J. Boyd ◽  
Jeffrey P. Szabo
Keyword(s):  
Crystal Structure ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Geometry Optimization ◽  
Membered Ring ◽  
Molecular Orbital Calculations ◽  
Bond Lengths ◽  
Comparison With Experiment ◽  
The Difference

Abinitio molecular orbital calculations are reported for several cyclic and acyclic sulfones. The geometries of XSO2Y, where X, Y = H, F, or CH3 are optimized at the STO-3G* level. Similar calculations are reported for the smallest cyclic sulfone, thiirane-1,1 -dioxide, as well as the corresponding sulfoxide, thiirane-1-oxide, and the parent sulfide, thiirane. Where comparison with experiment is possible, the agreement is satisfactory. In order to consider the possibility of substantial differences between axial and equatorial S—O bonds in the gas phase, as observed in the crystal structure of 5H,8H-dibenzo[d,f][1,2]-dithiocin-1,1-dioxide, STO-3G* calculations are reported for a six-membered ring, thiane-1,1-dioxide, and a model eight-membered ring. Limited geometry optimization of the axial and equatorial S—O bonds in the chair conformations of the six- and eight-membered rings leads to bond lengths of 1.46 Å with the difference being less than 0.01 Å.

Unlimited Freedom and illusion (On the basis of the plays “The Guardian” and “The Dwarfs” by H.Pinter)

2021 ◽  
Vol 15 (3) ◽  
pp. 68-71
Author(s):  
Solmaz Həşim qızı Ələsgərova ◽  
Keyword(s):  
Key Words ◽  
Virtual World ◽  
Psychological Disorders ◽  
English Drama ◽  
The Difference ◽  
The Guardian ◽  
Literary Trend

The English playwright Harold Pinter's plays "The Guardian" and "The Dwarfs" chosen from his drama are addressed to. The "chaotic world" observed in the plot of the plays is analyzed and the conclusion that the heroes are born of conflict in their relationships is defended. The object of research is to take into account the difference between the consciousness and reality. Issues such as conflicts of mind, aimlessness, phobias, the virtual world, lack of communication, psychological disorders of the personality are examined. As in Pinter's works, you can see the features of realism, romanticism, modernism, postmodernism, symbolism, surrealism, absurdism in the drama of Elchin, Kamal Abdulla and Firuz Mustafa. It is important to compare the Azerbaijani and English drama, which does not fit into the framework of any literary trend and is relevant as it lags behind time, in terms of plot, motives and artistic features. Key words: dramaturgy, fears and phobias, fantasy, loneliness and aggression,“madness”

Mitochondrial function in the presence of myoglobin

1982 ◽  
Vol 53 (5) ◽  
pp. 1116-1124 ◽  
Author(s):  
R. P. Cole ◽  
P. C. Sukanek ◽  
J. B. Wittenberg ◽  
B. A. Wittenberg
Keyword(s):  
Oxygen Consumption ◽  
Steady State ◽  
Liquid Phase ◽  
Gas Phase ◽  
Oxygen Pressure ◽  
Oxygen Electrode ◽  
Oxygen Binding ◽  
Atp Production ◽  
Skeletal Muscle Mitochondria ◽  
The Difference

The effect of myoglobin on oxygen consumption and ATP production by isolated rat skeletal muscle mitochondria was studied under steady-state conditions of oxygen supply. A method is presented for the determination of steady-state oxygen consumption in the presence of oxygen-binding proteins. Oxygen consumed in suspensions of mitochondria was replenished continuously by transfer from a flowing gas phase. Liquid-phase oxygen pressure was measured with an oxygen electrode; the gas-phase oxygen concentration was held constant at a series of fixed values. Oxygen consumption was determined from the characteristic response time of the system and the difference in the steady-state gas- and liquid-phase oxygen concentrations. ATP production was determined from the generation of glucose 6-phosphate in the presence of hexokinase. During steady-state mitochondrial oxygen consumption, the oxygen pressure in the liquid phase is enhanced when myoglobin is present. Functional myoglobin present in the solution had no effect on the relation of mitochondrial respiration and ATP production to liquid-phase oxygen pressure. Myoglobin functions in this system to enhance the flux of oxygen into the myoglobin-containing phase. Myoglobin may function in a similar fashion in muscle by increasing oxygen flux into myocytes.

VALUE ADDED TAX IN THE EUROPEAN UNION

2021 ◽  
Vol 62 (01) ◽  
pp. 186-189
Author(s):  
Nigar Yadulla Shahgaldiyeva ◽  
Keyword(s):  
European Union ◽  
Key Words ◽  
Value Added ◽  
The European Union ◽  
Value Added Tax ◽  
Tax System ◽  
Manufactured Goods ◽  
The Difference

Value-added tax is an indirect tax based on the sale value of goods, production and non-manufactured goods as an object of taxation. According to the mechanism and procedures for the calculation and payment of value added tax, this tax is not directly imposed by a particular person, but applies to consumers in the process of return. In this case, the value added tax is neutral for securities. In addition, value added tax is universal and is characterized by the difference between purchases at each stage of production and turnover. In connection with the calculation of value added tax, the taxpayer's tax liability to the budget consists of the difference between the amount of tax assessed on taxable turnover and the amount of tax to be deducted in accordance with the documents. Key words: European Union, value Added Tax, tax, tax system

PERSEPSI PENGGUNA JASA PENERBANGAN TERHADAP PELAYANAN MASKAPAI PENERBANGAN GARUDA INDONESIA DI KOTA BANDA ACEH

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Nadiya
Keyword(s):  
Service Quality ◽  
Key Words ◽  
Sampling Technique ◽  
T Test ◽  
Purposive Sampling ◽  
Good Assessment ◽  
The Difference ◽  
Differentiation Test ◽  
Banda Aceh

To determined whether the service quality of aviation is good can be seen from the ability of the service in achieving the expectation of the customer. This study aims to identify the difference between the expected service and the reality perceived by the customer in relation to the service of Garuda Indonesia airlines in Banda Aceh City.            This study used 99 customers of Garuda Indonesia Airline as the sample which is drawn by applying purposive sampling technique. Data was gathered by using questionnaire and analysis by using statistic tool, average differentiation test (t-test).            The result of statistic test shows t value is greater than the value of t-table. Thus, Ha is accepted while Ho is rejected which means there is average differentiation between the expected service and the perceived service of Garuda Indonesia’s customer            Generally, the customer has relatively good assessment towards the quality of Garuda Indonesia airlines. However, they still hope for better service in order to remains the gap between the expectation and the perceived service. Therefore, it is demanded for the management of Garuda Airlines to improve their provided service quality. Key words: User percepcion, Airline Service and Garuda Indonesia Banda Aceh  

Il soggetto che si dice nella poesia melica greca. Finzione enunciatva, immagini poetiche e pragmatica

PARADIGMI ◽  
2009 ◽  
pp. 85-99
Author(s):  
Calame Claude
Keyword(s):  
Key Words ◽  
Speech Act ◽  
Lyric Poetry ◽  
Greek Poetry ◽  
Written Text ◽  
The Difference

- Poetic images and Pragmatics Starting from Benveniste's analyses of historical enunciation, the nature of pronouns and the subjectivity of language, this essay focuses on that the kind of subjectivity implied in much Greek lyric poetry, especially in Pindar. By means of discursive tools, the narration builds an exclusively verbal image of the "I", which comes before any reference to elements external to the text. In this way, the "I" stands for an enunciative, pragmatic and polyphonic subject: it is, indeed, the actor (singer, tragic actor, choral group) of a ritualized situation. This performative identity is different from the author of the written text. In Greek poetry, the written text is above all a speech-act, mostly a song-act. This raises the problem of the difference - and of the relation - between the author's biographic subjectivity and the identity created by the linguistic devices in the text. Using different images: chariots, ceremonial processions, Calame's analysis focuses on the metaphorical identification between poetic song and journey.Key words: Enunciation, Image, Metaphor, Poetry, Pragmatics, Subjectivity.Parole chiave: Enunciazione, Immagine, Metafora, Poesia, Pragmatica, Soggettivitŕ. Vedere come.

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