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pKa Data Compiled by R. Williams pKa Values INDEX Inorganic 2 Phenazine 24 Phosphates 3 Pyridine 25 Carboxylic acids 4, 8 Pyrazine 26 Aliphatic 4, 8 Aromatic 7, 8 Quinoline 27 Phenols 9 Quinazoline 27 Alcohols and oxygen acids 10, 11 Quinoxaline 27 Amino Acids 12 Special Nitrogen Compounds 28 Peptides 13 Hydroxylamines 28 Nitrogen Compounds 14 ...

pKa Data Compiled by R. Williams pKa Values INDEX Inorganic 2 Phenazine 24 Phosphates 3 Pyridine 25 Carboxylic acids 4, 8 Pyrazine 26 Aliphatic 4, 8 Aromatic 7, 8 Quinoline 27 Phenols 9 Quinazoline 27 Alcohols and oxygen acids 10, 11 Quinoxaline 27 Amino Acids 12 Special Nitrogen Compounds 28 Peptides 13 Hydroxylamines 28 Nitrogen Compounds 14 Hydrazines 28

Pyridine, its N-oxide, and their derivatives are exciting classes of organic bases. These compounds show widespread biological activity, ...

This lone pair does not overlap with the aromatic π-system ring, consequently pyridine is basic, having chemical properties similar to those of tertiary amines.

Typically, imines have a pKa between 5 and 7, so this seems unusually high for a start. If this number is wrong then it means that pyridine may have quite a typical pKa for a cyclic imine of this type. I've not had time for a detailed search but I suspect this number may not be fully accurate.

-Reacts less readily with electrophiles than pyridine ... (less aromatic than pyridine) ... pKa 2.3. pKa 1.3. pKa 0.65. -Protonation. -N-alkylation.

From these pKa values, we can tell that the conjugate acid of pyridine is stronger than the conjugate acid of piperidine by about 6 pKa units.

Download scientific diagram | Plot of pKa values of protonated pyridine N-oxides vs. the corresponding substituent electrophilic s w values (correlation R 2 ...

Pyridine is a colorless liquid with an unpleasant smell. It can be made from crude coal tar or from other chemicals.Pyridine is used to dissolve other substances. It is also used to make many different products such as medicines, vitamins, food flavorings, paints, dyes, rubber products, adhesives, insecticides, and herbicides.

Pyridine is a basic heterocyclic organic compound with the chemical formula C. 5 H. 5 N. It is structurally related to benzene, with one methine group (=CH−) replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a distinctive, unpleasant fish-like smell.

Pyridine is a colorless liquid with an unpleasant smell. It can be made from crude coal tar or from other chemicals.Pyridine is used to dissolve other substances. It is also used to make many different products such as medicines, vitamins, food flavorings, paints, dyes, rubber products, adhesives, insecticides, and herbicides.

pKa Data Compiled by R. Williams. pKa Values. INDEX. Inorganic. 2. Phenazine. 24. Phosphates. 3. Pyridine. 25. Carboxylic acids.

The molecular electric dipole moment is 2.2 debyes. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10 cm ·mol . The standard enthalpy of formation is 100.2 kJ·mol in the liquid phase and 140.4 kJ·mol in the gas phase. At 25 °C pyridine has a viscosity of 0.88 mPa/s and thermal conductivity of 0.166 W·m ·K . The enthalpy of vaporization is 35.09 kJ·mol at the boiling pointand no…

Occurrence and Synthesis

pKa: –0.5. 1,2,3-Oxadiazole. 1,2,3-Triazole. pKa: 9.3. 1,3,4-Thiadiazole. pKa: –4.9. 2H-Pyran. 4H-Pyran. Pyridine. pKa: 5.2. Piperidine. pKa: 11.2.

The pKa of pyridine is 5.23(4), which indicates that pyridine will partially exist in the protonated form under acidic conditions and cations adsorb more ...

I have been trying to find the original data for the statement that the cyclic imine (or rather its conjugate acid) has a pKa of around 9. Typically, imines have a pKa between 5 and 7, so this seems unusually high for a start. If this number is wrong then it means that pyridine may have quite a typical pKa for a cyclic imine of this type.

Keywords: Pyridine, tautomeric equilibrium, conformation, acidity, basicity, pKa, solvation,. AM1, PM5, COSMO.