10.1021/acs.jpcc.7b02246.s001
Alberto Milani
Alberto
Milani
Matteo Tommasini
Matteo
Tommasini
Valentino Barbieri
Valentino
Barbieri
Andrea Lucotti
Andrea
Lucotti
Valeria Russo
Valeria
Russo
Franco Cataldo
Franco
Cataldo
Carlo S. Casari
Carlo S.
Casari
Semiconductor-to-Metal Transition in Carbon-Atom Wires
Driven by sp<sup>2</sup> Conjugated End Groups
American Chemical Society
2017
sp-hybridized carbon-atom wires
equalized
charge transfer
cumulene-like
Raman spectroscopy experiments
sp 2 end groups
polyyne-like
polyyne
bond
future all-carbon-based science
DFT
calculation
CAW
modulation
2017-04-24 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Semiconductor-to-Metal_Transition_in_Carbon-Atom_Wires_Driven_by_sp_sup_2_sup_Conjugated_End_Groups/4982942
Bis(biphenyl)-capped
polyynes are investigated to unveil the modulation
of the electronic and optical properties of sp-hybridized carbon-atom
wires (CAWs) capped with π-conjugated sp<sup>2</sup> end groups.
Raman and surface enhanced Raman spectroscopy experiments and density
functional theory (DFT) calculations reveal structural changes from
polyyne-like with alternating single–triple bonds toward cumulene-like
with more equalized bonds as a consequence of the charge transfer
occurring when wires interact with metallic nanoparticles. While polyynes
have semiconducting electronic properties, a more equalized system
tends to a cumulene-like structure characterized by a nearly metallic
behavior. The effect of different sp<sup>2</sup> end groups in driving
a semiconductor-to-metal transition is investigated by DFT calculations
on a series of CAWs capped with different terminations. We discuss
how the modulation of the structural, electronic, and vibrational
properties of the sp-carbon chain toward the metallic wire is not
trivial and requires a suitable chemical design of the end group and
control of charge transfer. These results provide a guideline for
the design of novel sp–sp<sup>2</sup> hybrid carbon nanosystems
with tunable properties, where graphene-like and polyyne-like domains
are closely interconnected. The capability to tune the final electronic
or optical response of the material makes these hybrid sp–sp<sup>2</sup> systems appealing for a future all-carbon-based science and
technology.