Methyl Cation Affinities of Neutral and Anionic Maingroup-Element Hydrides: Trends Across the Periodic Table and Correlation with Proton Affinities

2010 ◽  
Vol 114 (28) ◽  
pp. 7604-7608 ◽  
Author(s):  
R. Joshua Mulder ◽  
Célia Fonseca Guerra ◽  
F. Matthias Bickelhaupt
Keyword(s):  
Periodic Table ◽  
Proton Affinities ◽  
Methyl Cation

Correlation between Alkyl Cation Affinities and Proton Affinities—A Means to Rationalise Alkyl Group Substituent Effects

2000 ◽  
Vol 6 (2) ◽  
pp. 131-134 ◽  
Author(s):  
Einar Uggerud
Keyword(s):  
Linear Relationship ◽  
Alkyl Group ◽  
Substituent Effects ◽  
Alkyl Substituent ◽  
Thermochemical Data ◽  
Proton Affinities ◽  
Alkyl Groups ◽  
Substituent Constants ◽  
Straight Lines ◽  
Methyl Cation

Using literature thermochemical data it is demonstrated that the known linear relationship between proton affinities and methyl cation affinities can be extended to other alkyl groups (ethyl, i-propyl, t-butyl). It is suggested that the slopes of the straight lines can be used to define a new set of alkyl substituent constants.

New Theoretical and Experimental Proton Affinities for Methyl Halides and Diazomethane: A Revision of the Methyl Cation Affinity Scale

1994 ◽  
Vol 98 (50) ◽  
pp. 13099-13101 ◽  
Author(s):  
Mikhail N. Glukhovtsev ◽  
Jan E. Szulejko ◽  
T. B. McMahon ◽  
James W. Gauld ◽  
Anthony P. Scott ◽  
...  
Keyword(s):  
Proton Affinities ◽  
Methyl Halides ◽  
Cation Affinity ◽  
Methyl Cation

Proton affinities of the hydrogen, methyl, and trifluoromethyl halides from pulsed electron beam high pressure mass spectrometric equilibria measurements

1985 ◽  
Vol 63 (11) ◽  
pp. 3160-3167 ◽  
Author(s):  
T. B. McMahon ◽  
P. Kebarle
Keyword(s):  
High Pressure ◽  
Electron Beam ◽  
Mass Spectrometric ◽  
Proton Affinities ◽  
Methyl Halides ◽  
Hydrogen Halides ◽  
Pulsed Electron Beam ◽  
Linear Correlations ◽  
Mass Spectrometric Techniques ◽  
Methyl Cation

Pulsed electron beam high pressure mass spectrometric techniques have been used to investigate proton transfer equilibria involving hydrogen and trifluoromethyl halides. Methyl cation transfer equilibria have also been used to determine methyl cation affinities of hydrogen halides. Proton affinities obtained are HCl = 137.5, HBr = 142.9, Hl = 150.9, CF3Cl = 139.0, CF3Br = 141.3, and CF3l = 150.4 kcal mol−1. Methyl cation affinities obtained are HF = 15 ± 2, HCl = 19.8, HBr = 21.3, and Hl = 31.1 kcal mol−1. The values of methyl cation affinity of hydrogen halides can in turn be used to calculate proton affinities of the methyl halides of CH3Cl = 160.8; CH3Br = 164.8; and CH3l = 171 kcal mol−1. Linear correlations are found between proton affinities and valence ionization potentials and between proton affinities and methyl cation affinities.

Multislice calculations for quasi-periodic and non-periodic objects

1990 ◽  
Vol 48 (4) ◽  
pp. 138-139
Author(s):  
R. Herrera ◽  
A. Gómez
Keyword(s):  
Electron Diffraction ◽  
Computer Simulations ◽  
Periodic Table ◽  
Amorphous Materials ◽  
Space Group ◽  
Essential Step ◽  
Shape Effects ◽  
Atomic Scattering ◽  
Diffraction Patterns ◽  
Periodic Continuation

Computer simulations of electron diffraction patterns and images are an essential step in the process of structure and/or defect elucidation. So far most programs are designed to deal specifically with crystals, requiring frequently the space group as imput parameter. In such programs the deviations from perfect periodicity are dealt with by means of “periodic continuation”.However, for many applications involving amorphous materials, quasiperiodic materials or simply crystals with defects (including finite shape effects) it is convenient to have an algorithm capable of handling non-periodicity. Our program “HeGo” is an implementation of the well known multislice equations in which no periodicity assumption is made whatsoever. The salient features of our implementation are: 1) We made Gaussian fits to the atomic scattering factors for electrons covering the whole periodic table and the ranges [0-2]Å−1 and [2-6]Å−1.

A Well-Ordered Thing

2018 ◽  
Author(s):  
Michael D. Gordin
Keyword(s):  
Nineteenth Century ◽  
History Of Science ◽  
Periodic Table ◽  
The Arctic ◽  
Classic Work ◽  
Hot Air ◽  
History Of ◽  
First Time

Dmitrii Mendeleev (1834–1907) is a name we recognize, but perhaps only as the creator of the periodic table of elements. Generally, little else has been known about him. This book is an authoritative biography of Mendeleev that draws a multifaceted portrait of his life for the first time. As the book reveals, Mendeleev was not only a luminary in the history of science, he was also an astonishingly wide-ranging political and cultural figure. From his attack on Spiritualism to his failed voyage to the Arctic and his near-mythical hot-air balloon trip, this is the story of an extraordinary maverick. The ideals that shaped his work outside science also led Mendeleev to order the elements and, eventually, to engineer one of the most fascinating scientific developments of the nineteenth century. This book is a classic work that tells the story of one of the world's most important minds.

Color Coded Periodic Table

2018 ◽  
Author(s):  
Alexander Bolano
Keyword(s):  
Periodic Table
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