Relative Electron Densities in Substituted Benzenes<sup>1</sup>

Corio, P. L.; Dailey, B. P.

doi:10.1021/ja01594a029

Cited by 133 publications

(40 citation statements)

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“…The ultraviolet absorption maxima of many of these compounds a r e listed in Table I Scheme I) will scarcely alter the frequencies of absorption of the protons on the most distant ring d. On the other hand, on the bases of the known relative chemical shifts (as compared to benzene as a standard) for the benzenoid hydrogens in N-methylaniline (shift to higher field: 0.80 for o-H, 0.30 for m-H, and 0.57 for p-H, in p.p.m.) and in benzylamine (shift to higher field: 0.03 for each H) (14) were nearly identical as would be expected if absorption there resulted from some of the protons in ring d . Correspondingly, and consistent with expectations, absorptions in the range from 6.5 to ca.…”

supporting

confidence: 63%

Syntheses of benzo[b]‐ and benzo[j]phenanthridines

Klemm

Weisert

1965

Journal of Heterocyclic Chem

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The isomeric lactams benzo[b]phenanthridine‐5(6H)‐one and benzo[j]phenanthridine‐6(5H)‐one were obtained in equal yields by Schmidt reaction on 11H‐benzo[b]fluoren‐11‐one (44% total) or by Beckmann reaction on 11H‐benzo[b]fluoren‐11‐one oxime (22% total). Reduction of the lactams with lithium aluminum hydride gave the 5, 6‐dihydro‐benzo[b]‐ and ‐[j]phenanthridines. Dehydrogenation of these dihydro derivatives produced the parent aromatic heterocycles benzo[b]‐ and benzo[j]phenanthridine in best overall yields of 20% and 12%, respectively. A few substituted benzophenanthridines were also prepared. Assignment of structures was based on ultraviolet, infrared, and n.m.r. spectra of the dihydro derivatives as well as on separate unequivocal synthesis of the isomeric benzophenanthridines.

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supporting

confidence: 63%

Syntheses of benzo[b]‐ and benzo[j]phenanthridines

Klemm

Weisert

1965

Journal of Heterocyclic Chem

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“…In the light of this conclusion we can discuss the observations on monosubstituted benzenes made by Corio and Dailey [8]. They found that the aromatic part of the spectrum of toluene consists of one single line.…”

Section: Discussionmentioning

confidence: 74%

The redistribution of charge in naphthalene caused by methyl substitution

MacLean

Mackor

1960

Molecular Physics

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The proton resonance spectra at 40 Mc/s of solutions of symmetrically substituted dimethylnaphthalenes in carbon disulphide have been measured and interpreted. Methyl substitution causes changes of the chemical shifts of the various ring protons, which are discussed in terms of the inductive effect of the methyl group. It is shown that a correlation exists between the variations of these chemical shifts and the partial rate factors for H-D exchange.

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“…The impurity data given in Table I indicate that the high-purity silver used was actually an alloy with a melting range between the solidus and liquidus of a few tenths of a degree or less. 7 The melting range was determined primarily by the presence of oxygen in concentrations which may actually have been lower than the indicated 1-3 ppm because of a possible reducing effect of the graphite at 960°C. The decrease in Bragg intensity, beginning about 0.08C below the temperature at which melting was first observed, was therefore most likely due to the gradual formation of a two-phase solid-liquid structure starting at the solidus temperature and extending over a temperature range of a tenth of a degree or so.…”

Section: Discussionmentioning

confidence: 99%

“…in a second horizontal groove in the graphite core located just 3 mm above the top surface of the bar specimen ( (1) Gas-tight InconeI furnace tube, (2) graphite core, (3) x-ray grain in bar specimen, (4) Pt vs Pt-lO% Rh thermocouple, (5) fused quartz thermocouple tube, (6) thermocouple junction, (7) x-ray port heater winding, (8) Mylar window, (9) furnace casing, (10) powdered insulation, (11) incident and diffracted x-rays, (12) aperture in graphite core for x-rays, (13) longitudinal furnace heater, (14) water cooling tubes. men, because changes in the temperature gradients in the entire x-ray specimen region of the furnace were exceedingly small (see below).…”

Section: Specimen Temperaturementioning

confidence: 99%

X-Ray Diffraction Measurements of Silver during Slow Heating to the Melting Point

Beaman

Balluffi

Simmons

1964

The Journal of Chemical Physics

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Measurements of the x-ray lattice parameter, the Bragg diffraction peak intensity, and the diffraction peak width were made during the very slow quasiequilibrium heating of high purity silver (99.999+% pure) to the point where melting was observed. Back-reflection measurements were made using a 〈;422〉 reflection from a small homogeneously heated single crystal region under conditions allowing continuous visual observation of the x-rayed region. A specially developed technique allowed several thousand meassurements to be made in a temperature interval starting about 4°C below the onset of melting. Normal lattice expansion (to within ±Δa/a=3.8×10—6) was observed to within at least a few thousandths of a degree (°C) of the temperature at which melting was first clearly detected visually. The half-width of the Bragg peak remained constant over this range. A 50% decrease in intensity, however, was observed starting about 0.08°C below the point at which melting was first observed. This result was attributed to the gradual onset of two-phase alloy melting which was not immediately detected visually. This was consistent with chemical analysis which revealed the presence of sufficient impurities (mainly ∼1 ppm oxygen) to have produced a two-phase melting range between solidus and liquidus of the order of a tenth of a degree (°C). It was generally concluded that there was no evidence from the x-ray measurements of any anomalous lattice behavior (premelting phenomena) in silver at temperatures as close to the solidus absolute temperature as a few parts per million (or possibly less). This was consistent with the expected first-order nature of the transition.

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Relative Electron Densities in Substituted Benzenes¹

Cited by 133 publications

References 0 publications

Syntheses of benzo[b]‐ and benzo[j]phenanthridines

Syntheses of benzo[b]‐ and benzo[j]phenanthridines

The redistribution of charge in naphthalene caused by methyl substitution

X-Ray Diffraction Measurements of Silver during Slow Heating to the Melting Point

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Relative Electron Densities in Substituted Benzenes1

Cited by 133 publications

References 0 publications

Syntheses of benzo[b]‐ and benzo[j]phenanthridines

Syntheses of benzo[b]‐ and benzo[j]phenanthridines

The redistribution of charge in naphthalene caused by methyl substitution

X-Ray Diffraction Measurements of Silver during Slow Heating to the Melting Point

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Product

Resources

About

Relative Electron Densities in Substituted Benzenes¹