CONCERNING THE ORTHO SHIFT IN PROTON AND FLUORINE MAGNETIC RESONANCE OF SOME CONJUGATED HYDROCARBONS

1965 ◽  
Vol 43 (8) ◽  
pp. 2392-2397 ◽  
Author(s):  
F. Hruska ◽  
H. M. Hutton ◽  
T. Schaefer
Keyword(s):  
Magnetic Resonance ◽  
Bond Length ◽  
Ionization Potential ◽  
Linear Correlation ◽  
Conjugated Hydrocarbons ◽  
Monosubstituted Benzenes ◽  
First Ionization Potential

A linear correlation with Q is found for the shifts of protons or fluorines placed ortho or cis to the substituent in monosubstituted benzenes, ethylenes, propenes, monofluorobenzenes, and perfluorobenzenes. The substituent X corresponds to H, F, Cl, Br, I, and Q equals P/Ir3 where P is the polarizability of the C—X bond, r is the C—X bond length, and I is the first ionization potential of atom X. The correlation is useful for predicting some as yet unknown shifts in the above compounds. The significance of this correlation is discussed in an inconclusive manner.

Nuclear Magnetic Resonance Chemical Shifts of some Monosubstituted Isothiazoles

1975 ◽  
Vol 53 (4) ◽  
pp. 596-603 ◽  
Author(s):  
Roderick E. Wasylishen ◽  
Thomas R. Clem ◽  
Edwin D. Becker
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Charge Densities ◽  
Monosubstituted Benzenes ◽  
Proton Chemical Shifts ◽  
Nuclear Magnetic

Carbon-13 and proton chemical shifts have been measured for several monosubstituted isothiazoles. Substituent effects upon these chemical shifts are compared with those observed for monosubstituted benzenes, pyridines, and thiophenes. In general the observed substituent effects in the isothiazoles and thiophenes closely parallel one another. Correlations between the observed carbon-13 Chemical shifts and CNDO/2 calculated charge densities are examined.

scholarly journals Complex transition metal hydrides: linear correlation of countercation electronegativity versus T–D bond lengths

2015 ◽  
Vol 51 (56) ◽  
pp. 11248-11251 ◽  
Author(s):  
T. D. Humphries ◽  
D. A. Sheppard ◽  
C. E. Buckley
Keyword(s):  
Transition Metal ◽  
Bond Length ◽  
Linear Correlation ◽  
Metal Hydrides ◽  
Bond Lengths ◽  
Transition Metal Hydrides ◽  
Complex Hydrides

For homoleptic 18-electron complex hydrides, an inverse linear correlation has been established between the T–deuterium bond length and the average electronegativity of the metal countercations.

Benzene solvent induced shifts of the proton magnetic resonance spectra of some benzene derivatives. Importance of charge effects

1970 ◽  
Vol 48 (18) ◽  
pp. 2885-2895 ◽  
Author(s):  
R. Wasylishen ◽  
T. Schaefer ◽  
R. Schwenk
Keyword(s):  
Magnetic Resonance ◽  
Linear Correlation ◽  
Proton Magnetic Resonance ◽  
Steric Effects ◽  
Benzene Derivatives ◽  
Charge Effects ◽  
Solvent Shift ◽  
Solvent Shifts ◽  
Substituent Constants ◽  
Magnetic Resonance Spectra

The benzene solvent shifts of the proton magnetic resonance spectra of numerous polysubstituted benzene derivatives are measured with respect to cyclohexane as reference solvent. For many of these compounds, an additive scheme can be devised in which the effect of a substituent, X, on the solvent shift, Δ, of a proton is given by Δix so that Δ = Σx, Σi Δix where i = ortho, meta, or para. There is a linear correlation of Δmx or Δpx with Taft's substituent constants σm0 and σp0. It is suggested that charge effects are much more important than steric effects in determining both the magnitude and sign of Δ.

The 1650-1350 Å absorption spectrum of nitrogen dioxide

1962 ◽  
Vol 267 (1330) ◽  
pp. 395-407 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Nitrogen Dioxide ◽  
Ionization Potential ◽  
Ground State ◽  
Band System ◽  
Anharmonic Constant ◽  
Rydberg Transitions ◽  
First Ionization Potential

An analysis of the 1650-1350 Å band system of nitrogen dioxide has been carried out. A pattern of band spacings and intensities is found that is complex but regular. It is shown that this pattern is qualitatively, and to a large extent quantitatively, just what would be expected for a transition in which the shape of the molecule changes from bent to linear. The transition is a parallel one and the upper state has 2 Σ + u symmetry. The symmetrical stretching frequency is increased from its ground-state value to ca. 1420 cm -1 in the upper state. The upper-state bending frequency is ca. 600 cm -1 . The N — O length is decreased from its groundstate value, probably to 1·1(3) Å. The upper state resembles closely the ground state of NO + 2 . The transition is to be classed as one of the Rydberg transitions leading to the first ionization potential of NO 2 ; and the orbital to which the odd electron is transferred in the transition is (pσ) in type. The anharmonic constant g 22 for the linear upper state is found to be 2·(3) cm -1 . Other Rydberg transitions may well be present in the region, but have not been definitely identified.

Photoelectron Spectra and Molecular Properties, XLVIII Carbonates and Thiocarbonates

1975 ◽  
Vol 30 (11-12) ◽  
pp. 862-874 ◽  
Author(s):  
K. Wittel ◽  
E. E. Astrup ◽  
H. Bock ◽  
G. Graeffe ◽  
H. Juslén
Keyword(s):  
Ionization Potential ◽  
Substituent Effects ◽  
Lone Pair ◽  
Emission Spectra ◽  
Low Energy ◽  
Photoelectron Spectra ◽  
Energy Bands ◽  
Open Chain ◽  
First Ionization Potential ◽  
Cndo Calculations

Photoelectron (PE) spectra of ethylene and vinylene carbonates and thiocarbonates as well as of methylene trithiocarbonate and some open-chain derivatives are reported.The low energy bands, well separated in the unsaturated compounds, are assigned to lone pair and π type ionizations. The assignment is based on comparison of PE spectra, modified CNDO calculations, and sulfur Κβ emission spectra. The pronounced substituent effects due to which the first ionization potential varies from 8.4 eV to 11.1 eV are discussed.

A precise determination of the first ionization potential of benzene

1984 ◽  
Vol 108 (5) ◽  
pp. 420-424 ◽  
Author(s):  
S.C. Grubb ◽  
R.L. Whetten ◽  
A.C. Albrecht ◽  
E.R. Grant
Keyword(s):  
Ionization Potential ◽  
Precise Determination ◽  
First Ionization Potential
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