23303-09-5

Upstream product

• 14213-96-8 C₄H₄N^(1-)*C₂H₃N 
• 109-97-7 pyrrole 
• 70019-89-5 4-Methylimidazolate anion 

Downstream Products

• 109-97-7 pyrrole 
• 67131-48-0 formamide; deprotonated form 
• 2051-97-0 1-benzyl-1H-pyrrole 
• 58272-35-8 C₂H₄NO^(1-) 
• 77354-32-6 N-methylacetamide anion 
• 41458-22-4 2-Aminopyridin 

Relevant academic research and scientific papers

The Ionic Hydrogen Bond and Ion Solvation. 7. Interaction Energies of Carbanions with Solvent Molecules

The bonding energy of a water molecule to carbanions range from 11.0 kcal/mol for c-C5H5- to 13 - 15 kcal/mol for CH2CN-, CH2CHO-, and CH2COCH3- and to 16.2 kcal/mol for HCC-.Alcohols bond to c-C5H5- more strongly, by up to 20.6 kcal/mol for the strongly acidic CF3CH2OH, and the attachment energies show an inverse linear correlation with the acidities of the alcohols.The c-C5H5- ion exhibits unusual behavior in that it bonds to the hydrogen donor H2O more weakly (11.0 kcal/mol) than to CH3CN (15.5 kcal/mol).In contrast, the more localized pyrrolide ion c-C4H4N- bonds to the two solvents by comparable strength, 15.8 and 15.7 kcal/mol, respectively.These observations indicate a specific N-*OH hydrogen bonding contribution in c-C4H4N-*H2O, and/or an unusual C-*HC type hydrogen bonding contribution in c-C5H5-*CH3CN.As to structures, correlations between ΔHoD and ΔHoacid suggest that ligands may hydrogen bond to the ? system of c-C5H5-, and to the oxygen atoms in CH2CHO- and CH3COCH2-.The latter is supported by solvent shell effects in CH3COCH2-*nH2O.

Models for Strong Interactions in Proteins and Enzymes. 1. Enhanced Acidities of Principal Biological Hydrogen Donors

The acid dissociation energies of several key biological hydrogen donors are found to fall into a narrow range, ΔHoacid=352-355 kcal/mol.The strong acidities of these donor groups enhance the hydrogen bond strengths involved in the protein α-helix, imidazole enzyme centers and DNA.Specifically, the peptide link is modeled by the dipeptide analogue CH3CO-Ala-OCH3.Its acidity is strengthened, i.e. ΔHoacid is decreased by 8 kcal/mol compared with other amides, due to electrostatic stabilization by the second carbonyl in the peptide -CON-CH(CH3)CO- grouping.The acidity of imidazole is also strengthened by 8 kcal/mol compared with that of the parent molecule, pyrrole, primarily due to resonance stabilization of the ion.Hydrogen donor NH2 groups of adenine and cytosine are modeled by 4-aminopyrimidine, and the acidity of this amine group is strengthened by ring aza substitution.An intrinsic acidity optimized for hydrogen bonding strength therefore emerges as a common property of the diverse hydrogen donors in the protein α-helix, enzymes and DNA.This property may therefore be in part responsible for the natural selection of these molecules as principal biological hydrogen donors.