Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5375852 | Chemical Physics | 2008 | 8 Pages |
Abstract
DFT and ab initio MP2 calculations of optimal geometries, dipole moments, polarizabilities, excitation energies and enthalpies of hydrogen or proton transfer from N-H group for cyano derivatives of pyrrole are presented. CN groups in α and β positions have distinct effects on electron spectra absorption bands. CN in α position causes larger bathochromic shift in comparison to β position. N-H bond dissociation enthalpies (BDE) of substituted pyrroles are higher by 7 kJ molâ1 than pyrrole BDE. Number and position of CN groups do not affect BDEs. Proton affinities of pyrrolyl anions and enthalpies of electron transfer from these anions are proportional to the number of CN groups in molecule. Each CN group causes decrease in proton affinity by 72 kJ molâ1 and 73 kJ molâ1 rise in electron transfer enthalpy. For several studied pyrroles, BDEs, proton affinities and electron transfer enthalpies in water and benzene were computed.
Keywords
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Ján RimarÄÃk, VladimÃr LukeÅ¡, Erik Klein, Markus Griesser, Anne-Marie Kelterer,