The synthesis and non-linear optical properties of (N-alkylpyrrol-2-yl)squaraine derivatives. Part 1
作者:Daniel E. Lynch、Uwe Geissler、Ian R. Peterson、Mathias Floersheimer、Roland Terbrack、Li Feng Chi、Harald Fuchs、Nicolas J. Calos、Barry Wood、Colin H. L. Kennard、G. John Langley
DOI:10.1039/a604111f
日期:——
The synthesis of a soluble poly(pyrrolylsquaraine) was achieved by
N-alkylation of the pyrrole nucleus with
1-bromooctadecane and subsequent condensation with squaric acid.
Bis(1-octadecylpyrrol-2-yl)- squaraine was also produced and found to
exist in a variety of inseparable isomeric forms. When deposited as
Langmuir–Blodgett monolayers on hydrophilic substrates, these dyes
exhibit second harmonic generation (SHG) with
deff = 0.5 ±
0.1 pm V-1 for both. For comparison,
bis(3,5-dimethyl-1-octadecylpyrrol-2-yl)squaraine was synthesised and
revealed a higher SHG activity of
deff = 1.8 ±
0.2 pm V-1. Poly(1-octadecylpyrrolylsquaraine)
is the first alternating donor–acceptor polymer to give SHG.