Synthesis and nonlinear optical properties of two new two-photon initiators: Triphenylamine derivatives

Two new two-photon polymerization initiators, 1-{(1E)-2-[4-(diphenylamino)phenyl]vinyl}-4-[4-N,N-di-methylamino]benzene (PVMB) and 1-[(1E)-2-(4-{[4-((1E)-2-{4-[4-N,N-di-methylamino]phenyl}vinyl)phenyl]phenylamino}phenyl)vinyl]-4-[4-N,N-di-methylamino]benzene (DPVMB) have been synthesized with solid phase Wittig reaction. The single-photon fluorescence, quantum yields, lifetimes, solvent effects of the initiators were studied in detail and both compounds exhibited solvent-sensitivity. Two compounds are good two-photon absorbing chromophores and operative two-photon photopolymerization initiators. Two-photon absorption (TPA) cross-sections from 730 nm to 870 nm at intervals of 10 nm have been measured with the two-photon-induced fluorescence method, and the maximal values of the TPA cross-sections of PVMB and DPVMB are 1.6 GM and 19.9 GM (1 GM = 1 × 10⁻⁵⁰ cm⁴ s photon⁻¹ molecule⁻¹) at 800 nm, respectively. A microstructure has been fabricated by using DPVMB as initiator.