Synthesis, structure and nonlinear optical properties of two new one and two-branch two-photon polymerization initiators

Two new two-photon polymerization initiators, 1-{(1E)-2-[4-(diphenylamino)phenyl]vinyl}-4-[(4-N,N-di-n-butylamino)benzene (PVBB) and 1-[(1E)-2-(4-{[4-((1E)-2-{4-[4-N,N-di-n-butylamino] phenyl}vinyl)phenyl]phenylamino}phenyl)vinyl]-4-[4-N,N-di-n-butylamino]benzene (DPVBB) have been synthesized with a simple and effective solid phase Wittig reaction. The crystal structure of PVBB was determined by a four-circle diffractometer. The single- and two-photon absorption and fluorescence properties in five different solvents have been investigated in detail. Two-photon absorption (TPA) cross-sections from 730 nm to 870 nm at intervals 10 nm have been measured with the two-photon-induced fluorescence method. The maximal values of TPA cross-sections of PVMB and DPVMB are 12.9 GM and 63.3 GM (1 GM = 1 × 10−50 cm4 s photon−1 molecule−1) at 770 nm and 790 nm, respectively. We measured the quasi two-photon polymerization rates (Rp) based on scanning speed and the width of the written protruding line. Polymerization rates of DPVBB and PVBB were found to be 471 μm3 min−1 and 170 μm3 min−1, respectively. Furthermore, a three-dimension microstructure has been fabricated by using DPVBB as initiator.