Caveat regarding the use of substituent parameters in statistical analyses of molecular properties. II. Case study: carbon-13 NMR of 2-substituted pyridines and monosubstituted benzenes was written by Cook, Iain B.. And the article was included in Australian Journal of Chemistry in 1989.Recommanded Product: 2-Phenoxypyridine This article mentions the following:
Carbon-13 NMR substituent chem. shifts of equivalent positions on monosubstituted benzenes and 2-substituted pyridines are analyzed by multiple linear regression on combinations of field, resonance, electronegatively and three polarizability parameters. The ortho and meta positions of the 2-pyridine and benzene series are poorly described by σF and σR parameters, but a much improved fit is obtained when σx and/or a bond polarizability parameter σα (C-X) are included. The mechanism of shift formation differs markedly between the two systems when the C(2), C(4), and C(6) positions on pyridine are compared with the geometrically equivalent positions on benzenes. Owing to the high degree of interdependence between the four substituent effects, quant. anal. proved to be impossible. However, use of subsets of substituents with three of the four parameters approx. orthogonal enabled the mechanism to be deduced in most cases. It is postulated that the differences between the pyridine and benzene systems arises from perturbation of the C-N bond polarity. A mechanism to explain the results is presented. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Recommanded Product: 2-Phenoxypyridine).
2-Phenoxypyridine (cas: 4783-68-0) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of â?8.7 à 10â? cm3·molâ?.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·molâ? in the liquid phase and 140.4 kJ·molâ? in the gas phase. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Recommanded Product: 2-Phenoxypyridine