Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Langmuir – Blodgett films incorporating molecular wire candidates of ester-substituted oligo(phenylene – ethynylene) derivatives
AU - Villares, Ana
AU - Lydon, Donocadh
AU - Low, Paul
AU - Robinson, Benjamin
AU - Ashwell, Geoff
AU - Royo, Felix
AU - Pilar, Cea
PY - 2008/12/15
Y1 - 2008/12/15
N2 - Langmuir and Langmuir–Blodgett (LB) films of two “wire-like” oligo(phenylene–ethynylene) methyl ester derivatives, namely methyl-4-[(4″-(nonyloxyphenylethynyl)-4′-(phenylethynyl)]-benzoate and methyl-4-[(4″-hexadecyloxyphenylethynyl)-4′-(phenylethynyl]-benzoate (abbreviated as C9BPEB and C16BPEB), have been prepared and characterized. Surface pressure isotherms for both materials have been obtained, with C9BPEB showing more expanded monolayers. An analysis of the reflection spectra of monolayer films at the air–water interface suggests the formation of H-aggregates, and supports an organizational model in which tilt angles of C16BPEB and C9BPEB molecules with respect to the water surface are approximately 70° and 60°, respectively. The sequential transfer of monolayers of these BPEB ester derivatives onto solid substrates results in a Z-type deposition in the case of C9BPEB and Y-type for C16BPEB. The current–voltage (I–V) characteristics of LB monolayers are relatively symmetrical for both films, with the asymmetric contacts more evident in the I–V C16BPEB characteristics.
AB - Langmuir and Langmuir–Blodgett (LB) films of two “wire-like” oligo(phenylene–ethynylene) methyl ester derivatives, namely methyl-4-[(4″-(nonyloxyphenylethynyl)-4′-(phenylethynyl)]-benzoate and methyl-4-[(4″-hexadecyloxyphenylethynyl)-4′-(phenylethynyl]-benzoate (abbreviated as C9BPEB and C16BPEB), have been prepared and characterized. Surface pressure isotherms for both materials have been obtained, with C9BPEB showing more expanded monolayers. An analysis of the reflection spectra of monolayer films at the air–water interface suggests the formation of H-aggregates, and supports an organizational model in which tilt angles of C16BPEB and C9BPEB molecules with respect to the water surface are approximately 70° and 60°, respectively. The sequential transfer of monolayers of these BPEB ester derivatives onto solid substrates results in a Z-type deposition in the case of C9BPEB and Y-type for C16BPEB. The current–voltage (I–V) characteristics of LB monolayers are relatively symmetrical for both films, with the asymmetric contacts more evident in the I–V C16BPEB characteristics.
KW - Langmuir films
KW - Langmuir–Blodgett films
KW - UV–vis reflection spectroscopy
KW - Scanning tunneling microscopy
KW - Molecular wires
U2 - 10.1016/j.susc.2008.10.004
DO - 10.1016/j.susc.2008.10.004
M3 - Journal article
VL - 602
SP - 3683
EP - 3687
JO - Surface Science
JF - Surface Science
SN - 0039-6028
IS - 24
ER -