Novel multi-branched organic compounds with enhanced two-photon absorption benefiting from the strong electronic coupling

Two novel multi-branched organic compounds, 1,2,4,5-tetrakis[(4′-N,N-diethylamino)styryl]benzene (TDEASB) and 1,2,4,5-tetrakis[(4′-N,N-dibutylamino)styryl]benzene (TDBASB), with strong electronic coupling among the conjugated arms, have been designed and synthesized. Their single-photon and two-photon absorption (TPA) and photoluminescent (PL) properties have been studied carefully. The two-photon absorption cross-sections of the two compounds were estimated by two-photon excited fluorescence technique using 200 fs, 76 MHz, Ti:sapphire laser, which are as high as 810 and 1030 GM for TDEASB and TDBASB, respectively. The strong TPA cross-sections indicate excellent conjugation and electron delocalization properties in these benzene-core based multi-branched compounds.