title: Molecular electrostatic potential for exploring π-conjugation: a density-functional investigation.
abstract: Molecular electrostatic potentials (MESP) of the most common building blocks of organic π-conjugated systems, viz. ethylene, acetylene, benzene, furan, pyrrole, thiophene and phenylvinylene, are examined at the B3LYP/6-311++G(2d,2p) level. The topography of MESP is employed for mapping the strength of electronic conjugation between these building blocks. When electron-rich molecular regions are connected to each other, the MESP value of the corresponding conjugation critical point (CCP) is able to provide a quantitative measure of the strength of the conjugation. The systems with stronger conjugation are generally seen to possess a larger negative value of CCP and a smaller difference (ΔV(CM-CCP)) between the MESP values of respective conjugated minimum (CM) and the CCP, in agreement with the experimental as well as other theoretical results. The present MESP topography-based approach thus offers a measure of the quantitative strength of π-conjugation in molecules.
authors.affiliation: Department of Chemistry, University of Pune, Pune-411007, India. sspingale@chem.unipune.ac.in
authors.forename: Subhash S
authors.initials: SS
authors.lastname: Pingale
mesh_terms: D000114:Acetylene / Q000737:chemistry; D001554:Benzene / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry; D011789:Quantum Theory; D055672:Static Electricity; D013876:Thiophenes / Q000737:chemistry
chemical_list: D005030:Ethylenes; D005663:Furans; D011758:Pyrroles; D013876:Thiophenes; C036216:ethylene; D001554:Benzene; D000114:Acetylene