Crystal structures, two-photon excited fluorescence and bioimaging of Zn(II) complexes based on an extended 2,2′-bipyridine ligand

•Two new luminescent zinc dyes were prepared.•The dyes exhibit two-photon excited fluorescence with two-photon absorption cross-section values up to 682 GM.•The structure-property relationships were detailed through X-ray crystallography.•Results of living cell imaging experiments show the value of the dyes in fluorescence microscopy bioimaging applications.

Two new luminescent zinc complexes based on a donor–π–bridge- acceptor organic ligand bearing a diphenylamine donor group and 2,2′-bipyridine acceptor group were prepared and characterized. The structures of the dyes were solved by single crystal X-ray diffraction analysis. Research has shown that the dyes exhibit superior two-photon excited fluorescence with the large two-photon absorption cross-section values of over 630 GM. The structure-property relationships were detailed through X-ray crystallography. Results of living cell imaging experiments show the potential of these dyes in fluorescence microscopy bioimaging.

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