Chromophores two-photon absorbing

For two-photon memories, a number of media types and reading mechanisms have been used (165). Generally, media comprise two photon-absorbing chromophores dissolved within a soHd polymer matrix. Suitable reversible photochromic dyes are, for example, spiropyrans. Although photochromic materials often suffer from photobleaching, as well as from instability leading to self-erasure, new materials and host environments are under development (172). Bacteriorhodopsin (BR) also has been proposed as a two-photon memory material. 

Carbazole-containing stilbene analogues have been shown to be efficient two-photon absorbing chromophores <2000TL8573>. 

R. Sivaraman, S. J. Clarson, B. K. Lee, A. J. Steckl, and B. A. Reinhardt. Photoluminescence studies and read/write process of a strong two-photon absorbing chromophore. Appl. Phys. Lett., 77(3) 328-330, July 2000. 

Preparation of two novel two-photon polymerization initiators, 10-ethyl-3 -E-(4-(N,N -di- -butyl-amino)styryl)phenofliiazine-5 and 10-ethyl-3,7-E,E-bis(4-(N,N -di-butylamino)styryl)phenothiazine-6 was reported. These initiators were found to exhibit good single-photon fluorescence. Synthesis, structures, and properties of two additional two-photon photopolymerization initiators was reported. The compounds are diphenyl-(4- 2-[4-(2-pyridin-4-ylvinyl)phenyl]vinyl phenyl)amine and 9-(4- 2-[4-(2-pyridin-4-ylvinyl)-phenyl]vinyl phenyl)-9H-carbazole. Both compounds were found to be good two-photon-absorbing chromophores and effective two-photon photopolymerization initiators. 

FIGURE 49.18. Molecular structures of various two-photon absorbing chromophores with different 7r-bridges. 

Hayek A, Bolze F, Bourgogne C, Baldeck CL, Didier P, Amtz Y, Mely Y, Nicoud JF (2009) Boron containing two-photon absorbing chromophores. 2. Fine tuning of the one- and two-photon photophysical properties of pyrazabole-based fluorescent bioprobes. Inorg Chem 48 9112-9119... 

A further extension of the spectroscopic characterization of [2.2]paracyclophane-stacked oligomers reveals that interchain interactions between conjugated segments have distinctly different effects on one- and two-photon absorption [107,112,113]. This finding may provide impetus for the design of new two-photon absorbing chromophores and for further exploration of the role of aggregation of these dyes. 

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