Synthesis and Characterization of Two-Photon Absorbing Dithienothiophene Derivative with Silyl End Group

Abstract

Efficient two-photon absorbing chromophore based on dithienothiophene has been synthesized and its two-photon absorption cross section (σ₂) was evaluated by two-photon induced fluorescence excitation spectroscopy. The chromophore obtained shows a sizable two-photon absorption cross section value of 618 GM at 700 nm. By using one- and two-photon spectroscopic experiment, two-photon absorption properties of the chromophore with the electronic transition dipole moment and one- and two-photon transition energies were evaluated. Besides, we have demonstrated the successful application of this compound in fabrication of 2D and 3D microobjects by using two-photon microfabrication technique.

Keywords:

• 3D microfabrication
• dithienothiophene
• two-photon absorption

Acknowledgments

This work was supported by the Active Polymer Center for Pattern Integration from the Korea Science & Engineering and also the Korean Ministry of Science and Technology (M10503000217-05M0300-217). The authors acknowledge the help of Dr. Patrice Baldeck for performing part of the TPA measurement.

Notes

All data in this table was measured in THF.

^a Molar extinction coefficient.

^b Energy of the transitions between the ground state and the one-photon allowed excited state.

^c Band width (FWHM).

^d Oscillator strength.

^e Transition dipole moment.

^f Fluorescence quantum yield.

^g Two-photon absorption cross section (1 GM = 1 × 10⁻⁵⁰ cm⁴ s photon⁻¹ molecule⁻¹). Experimental uncertainty:±15 %.