We have studied structural and electronic properties of the three dimensional crystalline regions of Emeraldine II polymers, in the base (EB-II) and salt (ES-II) forms, by means of first principle Car-Parrinello molecular dynamics. We compare the geometrical structures of the polymer chains in the primitive cells of EB-II and ES-II, pointing out the structural effects due to the protonation with HCl of the imminic nitrogens in the EB-II chains and the effect of the counterions between neighboring chains. We also analyze the HOMO electron density distribution, band structure and density of states of the resulting bipolaronic structure of ES-II, which is energetically stable and has a semiconductor character with a forbidden gap of the order of 0.6 eV.
Base and salt 3D forms of emeraldine II polymers by Car-Parrinello molecular dynamics / CAVAZZONI C.; COLLE R.; FARCHIONI R.; GROSSO G.. - In: COMPUTER PHYSICS COMMUNICATIONS. - ISSN 0010-4655. - STAMPA. - 169:(2005), pp. 135-138. [10.1016/j.cpc.2005.03.032]
Base and salt 3D forms of emeraldine II polymers by Car-Parrinello molecular dynamics
COLLE, RENATO;
2005
Abstract
We have studied structural and electronic properties of the three dimensional crystalline regions of Emeraldine II polymers, in the base (EB-II) and salt (ES-II) forms, by means of first principle Car-Parrinello molecular dynamics. We compare the geometrical structures of the polymer chains in the primitive cells of EB-II and ES-II, pointing out the structural effects due to the protonation with HCl of the imminic nitrogens in the EB-II chains and the effect of the counterions between neighboring chains. We also analyze the HOMO electron density distribution, band structure and density of states of the resulting bipolaronic structure of ES-II, which is energetically stable and has a semiconductor character with a forbidden gap of the order of 0.6 eV.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
