| 초록 |
Two photon absorbing (TPA) chromophores find numerous applications in fields such as 3D micro-fabrication, photodynamic therapy, optical power limiting, optical data storage, etc. Fluorene molecule is known to have high fluorescence quantum yield and thermal efficiency. In this work, we have designed and prepared new spiro-fluorene (DTF) based quadrupolar TPA chromophores with D-π-D architecture, DTF-1 and DTF-2 having triphenylamine and N,N-dibutylbenzenamine as donors, respectively. The substituted fluorene derivatives have spiro-structures with perpendicular alignment of the side group with respect to the pi-center. This structure assists in preventing intermolecular fluorescence quenching which is common in case of dyes. As a result, these compounds possess higher two photon absorption efficiency. The electron donability of the side groups were correlated with observed values of TPA cross section. The compounds were employed as photosensitizers in two photon lithography in the fabrication of 2D and 3D micro objects. |
