- Benzimidazoline
Chembox new
ImageFile = Benzimidazoline numbering.png
ImageSize = 150px
IUPACName = 2,3-Dihydro-1"H"-benzimidazole
OtherNames = Dihydrobenzimidazole
Section1 = Chembox Identifiers
CASNo = 4746-67-2
PubChem =
SMILES = C12=CC=CC=C1NCN2
Section2 = Chembox Properties
C=7 | H=8 |N=2
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Section3 = Chembox Hazards
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Autoignition =A benzimidazoline or dihydrobenzimidazole is a
nitrogen heterocycle based on abenzene ring fused with animidazoline . The parent compound has thechemical formula C7H8N2.Benzimidalolines in dihydrogen storage
In one study certain benzimidazolines have been identified as organic
hydride s that can be applied inchemical hydrogen storage . ["Hydrogen evolution from organic hydrides" Daniel E. Schwarz, Thomas M. Cameron, P. Jeffrey Hay, Brian L. Scott, William Tumas and David L. ThornChemical Communications , 2005, (47), 5919 - 5921 [http://www.rsc.org/publishing/journals/CC/article.asp?doi=b511884k Abstract] ] Benzimidazoline 1 converts in presence ofpalladium(II) acetate inacetonitrile atroom temperature to theinternal salt 2 with formation ofhydrogen gas. The salt forms between thebenzoic acid anion and theimidazolium cation where the positive charge is delocalized over 3 atoms. This reaction even takes place in a 3.5 atmosphere of hydrogen. The reaction of benzimidazoline 3 withacetic acid overpalladium powder has the same result and 1,3-dimethylbenzimidazoline without a 2-substituent even reacts with water.This type of reactivity is unusual. Few
exergonic reaction s exist that liberate hydrogen like thechemical decomposition offormic acid to hydrogen andcarbon dioxide . Computations show that the conversion of 1 too is anexergonic reaction with aGibbs free energy of - 21.8 kJ/mol. The formation of (persistent)carbene s from certainimidazolium salts withsodium hydride also generates hydrogen but these reactions are endergonic.References
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