Abstract
Poly(triacetylenes) are rodlike molecules with electrons delocalized over a one-dimensional path. We show that they exhibit a power-law dependence of the second-order hyperpolarizability γ on the monomer unit n for short molecules and a smooth saturation toward a linear increase in longer molecules. The power law of γ ∝ na with a ≈ 2.5 from dengenerate four-wave mixing and third-harmonic generation measurements is in good agreement with quantum-chemical calculations. The critical conjugation length for saturation in the three cases is shown to be approximately 60 carbon-carbon bonds, which indicates the upper boundary for the electron delocalization in such a one-dimensional molecular wire.
Original language | English (US) |
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Pages (from-to) | 1599-1601 |
Number of pages | 3 |
Journal | OPTICS LETTERS |
Volume | 24 |
Issue number | 22 |
DOIs | |
State | Published - Nov 15 1999 |
Externally published | Yes |
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics