## Abstract The effect of substituents on the proton chemical shifts and spin–spin coupling constants in __ortho__‐, __meta__‐ __and para__‐substituted 5‐phenyltetrazoles (tetrazolic acids) in DMSO–CH~3~CN (1:1, v/v) was studied. With the __meta__‐ and __para__‐ substituted compounds the additivity
A unified correlation of substituent effects with carbon, proton and fluorine chemical shifts in aromatic and olefinic systems
✍ Scribed by William B. Smith; Thomas W. Proulx
- Publisher
- John Wiley and Sons
- Year
- 1976
- Tongue
- English
- Weight
- 560 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
At the present time no completely satisfactory quantum mechanical calculations exist for carbon, proton or fluorine chemical shifts in various substituted aromatic or olefinic systems. However, the chemical shifts in such systems have been shown to be well correlated by a linear multiple regression analysis with the Swain and Lupton field and resonance para meters ℱ and ℛ, and the semiempirical parameter Q. The utility of Q in testing substituent stereochemistry has been exemplified previously. Here the applications of the complete regression analysis to a wide variety of different systems for the three nuclei are given. The correlation is also shown to apply to selenium in substituted selenophenes. The ^13^C chemical shifts for a series of ortho substituted toluenes are presented and comparisons made with other ortho disubstituted benzenes.
📜 SIMILAR VOLUMES
## Abstract A regular relationship was noted between the influence of substituents on the chemical shifts of the __ortho__ protons in mono‐substituted benzenes and the influence of the same substituents on the protons in the __cis__ relationship in monosubstituted ethylenes.
## Abstract The carbon‐13 shifts of C‐1, C‐2 and C‐3 are determined in a series of 1‐cyclohexen‐3‐ones substituted in position 1. Linear relationships are demonstrated between the substituent chemical shifts of corresponding carbons in substituted ethylenes, butadienes, α‐enones and benzenes. The s
## Abstract The proton chemical shifts are reported for monosubstituted naphthalenes, quinolines and quinoxalines. Together with literature data, these chemical shifts are compared with the parent compounds and substituent effects evaluated statistically. The effect of substituents parallels that i
## Abstract A correlation of __para__ substituted ^13^C chemical shifts in aromatic compounds with substituent polar (inductive) and resonance constants σ\* and σ^r^ of aliphatic compounds has been studied. It has been shown that the precision of the correlations obtained corresponds to that of the