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Volume 7
Innovative Energy & Research
ISSN: 2576-1463
Advanced Energy Materials 2018
August 13-14, 2018
August 13-14, 2018 | Dublin, Ireland
20
th
International Conference on
Advanced Energy Materials and Research
Polyacetylene: Myth, reality and a way forward
Bruce S Hudson
Syracuse University, USA
P
olyacetylene, the simplest and oldest conducting polymer, has never been made in a form that permits rigorous
determination of its structure. Trans polyacetylene will have two equivalent potential energy minima. It has been
assumed that this results in bond length alternation. It is, however, very likely that the zero-point energy is above the Peierls
barrier. Experimental studies that purport to show bond alternation have been reviewed and shown to be compromised by
experimental inconsistencies or by the presence of finite chain polyenes. This situation has been reviewed in an open paper. A
method for preparation of high molecular weight polyacetylene with fully extended chains that are prevented from reacting
with neighboring chains by photochemical polymerization of a reactive guest molecule in urea inclusion complexes (UICs) is
then discussed. The structural chemistry of these UIC materials will be reviewed. Our current projects involve guest species
diiodo butadiene or diiodo hexatriene. The loss of iodine atoms during the elimination polymerization is monitored by weight
loss. The polyacetylene chains form in UIC channels as fully extended chains that are parallel with a separation of 0.82 nm in
a hexagonal lattice. The diene and triene guest species differ in crystal morphology with the triene presenting with hexagonal
needles. Raman spectroscopy used to monitor the formation of polyene chains suffers loos of intensity when the chains are very
long. The final material is characterized by vibrational inelastic neutron scattering using VISION at the Oak Ridge National
Laboratory. Our ultimate objective is to measure electrical conduction of polyacetylene in urea inclusion compounds along
the c-axis of the hexagonal channel. The strong bonding of carbons atoms suggests that this material may be a superconductor
at room temperature due to the lack of thermally populated phonons. Methods for the formation of closed loop structures are
being considered.
Recent Publications:
1. Hudson B S and Allis D G (2013) Bond alternation in infinite periodic polyacetylene: dynamical treatment of the
anharmonic potential. Journal of Molecular Structure 1032:78-82.
2. Dinca S A, Allis D G, Lashua A F, Sponsler M B and Hudson B S (2015) Insulated polyacetylene chains in an inclusion
complex by photo polymerization. In Crystal Engineering - Design, New Materials and Application 1799:7-12.
3. Lashua A F, Smith T M, Hu H, Wei L, Allis D G, Sponsler M B and Hudson B S (2013) Commensurate urea inclusion
crystals with the guest (e,e) 1,4-diiodo-1,3-butadiene. Crystal Growth & Design 13:3852-3855.
Bruce S Hudson, Innov Ener Res 2018, Volume 7
DOI: 10.4172/2576-1463-C1-002