Hits:

Indexed by:期刊论文

Date of Publication:2014-11-01

Journal:JOURNAL OF CLUSTER SCIENCE

Included Journals:SCIE

Volume:25

Issue:6

Page Number:1501-1510

ISSN No.:1040-7278

Key Words:Polyaniline; PCM; DFT; Frontier molecular orbitals

Abstract:The theoretical calculation of polyaniline tetramers were performed in implicit water solvent medium using the polarizable continuum model with density functional theory. In order to explore the protonation mechanism of polyaniline, the geometry characteristics, charge distribution, frontier molecular orbitals (MOs) and stability of emeraldine base and emeraldine salts in tetramer were investigated by B3LYP/6-31G+(d,p), and the significant increase mechanism of the electrical conductivity of polyaniline upon protonation was researched in detail. It was shown that optimized molecular geometry by protonation doping suggested a tendency towards bipolaron delocalization and a greater pi-conjugation proved by bond length alternation and the torsional angles. Furthermore, the NBO of ES3 was distributed equably and should be conducive to the electrical conductivity, the frontier MOs were effectively established, and an electronic transition from HOMO to LUMO+1 is turned out to be a pi pi* transition finally. In addition, compared with the computed energies of different emeraldine salt configurations, the bipolaronic lattice was taken for the most stable structure.