PMR Spectra Of The 4-alkylnitrobenzenes

Evidence of first-order alkyl-ring proton coupling is reported for the 4-alkylnitrobenzenes. Typical coupling constants of 0.7 Hz and 0.3 Hz were found for α-alkyl coupling with the ortho and meta ring protons, respectively, when the alkyl function was methyl, ethyl, and isopropyl. No β-alkyl coupling with ring protons was observed for the ethyl, isopropyl, or t -butyl groups, suggesting that the magnitude of the coupling constant is vanishingly small

The Internal Chemical Shift - A Key To Bonding In Aromatic Molecules. 2. Substituent Effects On The Carbon-13 Magnetic Resonance Spectra Of The 1,4-disubstituted Benzenes

Carbon-13 magnetic resonance shifts were determined for six families of 1,4-disubstituted benzenes. Linear least-squares correlations between the internal shifts of the families suggest an additivity relationship for 13C substituent effects at all four nonidentical ring carbons and at the α position when one of the substituents has a central carbon. The correlation of 1H and 13C shifts for these compounds is also linear, implying that the additivity relationships derived in a previous 1H study can be generalized to 13C

Proton Shift Additivity And Substituent Interaction Parameters

The 4-substituted acetophenone family is characterized and its shifts are correlated with those of nine families of 1, 4-disubstituted benzenes reported previously. Then a simple mathematical model is derived to account for the proton magnetic resonance shifts within families of 1, 4-disubstituted benzenes. The model suggests that the substituents interact by σ-bond polarization. The polarization model rationalizes shift additivity and is consistent with the qualitative relationship between the number of valence electrons on a substituent and its capacity to induce shifts. © 1977, American Chemical Society. All rights reserved

The Internal Chemical Shift. A Key To Bonding In Aromatic Molecules. I. Internal Shift Correlations

The study of proton shift behavior in nine families of disubstituted benzenes has provided quantitative correlations of internal and meta shifts among all families. The equations of correlation are useful in the prediction of shifts to an error of 0.015 ppm. The studies demonstrate shift additivity for the 4-substituted halobenzenes and suggest a chain rule relationship for substituent effects in those compounds. For that reason, previous theories of substituent interactions involving inductive and resonance contributors appear incorrect when applied to proton shift data. In decreasing order of up field shift at the ortho protons the substituents studied include N(CH3)2, NH2, OCH3, OH, F, CH3, CH2CH3, H, Cl, C(CH3)3, Br, CN, COOCH3, COOH, COCI, NO2. © 1973, American Chemical Society. All rights reserved

Schola Disciplinæ Religiosa. Id Est Asceseologia Dominicalibus Evangeliis per annum quodammodò accommodata tam Ordinis cujusvis Superioribus, quam animarum Curatoribus perquàm utilis : Distinctis Lectionibus Ascetico-Moralibus ad FF. Clericos seu Juvenes Professos Ordinis Minorum S. P. Francisci Strictioris Observantiæ Recollectorum Almæ & Antiquissimæ Provinciæ Argentinensis seu Alemanniæ Superioris, sub Instructorum Curâ, & Disciplinâ etiamnum constitutos habita

à P. F. Columbano Beistel Ejusdem Ordinis MinimoFrontispizAus dem Vorbesitz des Klosters Rheinau. Exlibris mit der Legende: "Sub Abbate Ianuario I." im vorderen Spiegel Exemplar der ZB Züric