𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Solvent versus substituent effects on the nitrogen NMR shielding of the nitro-group in substituted benzenes

✍ Scribed by Michal Witanowski; Wanda Sicinska; Zenobia Biedrzycka; Graham A. Webb

Publisher
John Wiley and Sons
Year
1993
Tongue
English
Weight
359 KB
Volume
31
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Intermolecular effects are shown to induce a variation of about 5 ppm in the nitrogen NMR shieldings of aromatic nitro groups. The latter turn out to be comparable to those exerted by substituents in nitrobenzene derivatives in solutions in a given solvent. Substituent effects on the NO~2~ nitrogen shielding in nitro benzenes, in a given solvent, seem to reflect contributions from the so‐called field‐inductive effects on the electron charge distribution in such systems, and are insensitive to the resonance effects concerned with the delocalized pπ‐electron systems involved.

πŸ“œ SIMILAR VOLUMES

Solvent-Induced Effects on the Nitrogen
Solvent-Induced Effects on the Nitrogen NMR Shieldings of Some Nitrosobenzene Systems
✍ M. Witanowski; Z. Biedrzycka; W. Sicinska; G. A. Webb πŸ“‚ Article πŸ“… 1997 πŸ› John Wiley and Sons 🌐 English βš– 260 KB πŸ‘ 2 views

High-precision 14N NMR measurements of solvent-induced shielding variations are reported for some nitrosobenzene systems. These variations are shown to result from a combination of three major factors, solvent to solute hydrogen bonding where the solute nitrogen lone pair electrons are involved, sol

Hydrogen Bonding and Solvent Polarity Ef
Hydrogen Bonding and Solvent Polarity Effects on the Nitrogen NMR Shielding of 1,2,4,5-Tetrazine
✍ M. Witanowski; Z. Biedrzycka; W. Sicinska; Z. Grabowski; G.A. Webb πŸ“‚ Article πŸ“… 1997 πŸ› Elsevier Science 🌐 English βš– 96 KB

Results of the first extensive investigation of the nitrogen published work on solvent-induced effects on nitrogen shielding of 1,2,4,5-tetrazine ( I ) are reported. Due attention shieldings is 1,2,4,5-tetrazine: is paid to solvent-induced nitrogen-shielding variations by a variety of solvents. A co

Solvent Effects on the Nitrogen NMR Shie
Solvent Effects on the Nitrogen NMR Shielding of 2-Methyl-2-nitrosopropane and its Azodioxy Dimer
✍ M. Witanowski; Z. Biedrzycka; G. A. Webb πŸ“‚ Article πŸ“… 1996 πŸ› John Wiley and Sons 🌐 English βš– 338 KB πŸ‘ 2 views

High-precision 14N NMR shielding data are reported for 2-methyl-2-nitrosopropane and its azodioxy dimer in a variety of solvents. A range of about 30 ppm, as a function of solvent, is observed for the nitroso nitrogen atom. This contrasts with the corresponding shielding range for the dimer, which i

A Study of Solvent Polarity and Hydrogen
A Study of Solvent Polarity and Hydrogen Bonding Effects on the Nitrogen NMR Shielding of Isomeric Tetrazoles andab InitioCalculation of the Nitrogen Shielding of Azole Systems
✍ M. Witanowski; Z. Biedrzycka; W. Sicinska; Z. Grabowski πŸ“‚ Article πŸ“… 1998 πŸ› Elsevier Science 🌐 English βš– 136 KB

High-precision nitrogen NMR shieldings, bulk susceptibility corrected, are reported for the N-methyl derivatives of the two existing isomeric tetrazoles (I, II) in a variety of solvents which represent a wide range of solvent properties from the point of view of polarity as well as hydrogen bond don

Study of hydrogen bonding and solvent po
Study of hydrogen bonding and solvent polarity effects on the nitrogen NMR shieldings of N,N-dimethylacetamidine
✍ Michal Witanowski; Wanda Sicinska; Zenobia Biedrzycka; Graham A. Webb πŸ“‚ Article πŸ“… 2000 πŸ› John Wiley and Sons 🌐 English βš– 148 KB πŸ‘ 2 views

Solvent effects on the nitrogen shieldings of N,N-dimethylacetamidine (1) were found to be extremely large for the imino group (about 120 ppm) and for the amino moiety (about 50 ppm). A detailed analysis of the solvent-induced variations revealed contributions from three large interactions. These ar