Related Experiment Video
Updated: Aug 18, 2026

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Structure-activity relationships of selected pyridines. I. Substituent constant analysis
Abstract:
Twenty-two four-position derivatives of pyridine (C5H5N) were tested following an acute static regime with biological response being monitored as population growth of Tetrahymena pyriformis. The vinyl derivative was the most active and the hydroxy derivative was the least active. Structure-activity relationships were examined using substituent constants as molecular descriptors. Size/shape parameters and hydrophobic/hydrophilic parameters were found to be more important descriptors than electronic parameters. Following the deletion of the outliers, 4-vinylpyridine and 4-nitropyridine, molar refractivity was found to be the best single descriptor explaining 62.5% of the variability in biological response. Based on highest adjusted r2 value the best model is log BR = 0.0055 (MR) - 0.3699 (Ha) - 1.0124, r2 = 0.709 (BR, biological response; MR, molar refractivity; Ha, hydrogen acceptance). Models using Pi (hydrophobic substituent constant) as the descriptor and comparisons with previously assayed naphthalenes are discussed.
More Related Videos
Related Concept Videos
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Five-Membered Heterocyclic Aromatic Compounds: Overview
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Basicity of Heterocyclic Aromatic Amines
Nomenclature of Aryl and Heterocyclic Amines
Basicity of Aromatic Amines

