Self-assembly of a series of thiocyanate complexes with high two-photon absorbing active in near-IR range and bioimaging applications

Article abstract of DOI:10.1016/j.dyepig.2015.03.039

Abstract A series of novel complexes bearing high fluorescence quantum yields and showing the peak two-photon absorption (2 PA) cross-sections in the near-infrared region, Zn(SCN)₂L₂(1), [Cd(SCN)₂L₂]_n(2), Co(SCN)₂L₄(3), Ni(SCN)₂L₄(4), [CdHgL₂(SCN)₄]_n(5) and [MnHg(SCN)₄L₂]_n(6), containing functional chromophore (L = (E)-(4-diethyl anilinostyryl)pyridine), were synthesized in high yields. Crystal structures of all the complexes were confirmed. Hetero-metal complexes (5, 6: L:M = 1:1) present much higher two-photon absorption (2 PA) cross-sections (σ) in comparison with those of the homo-metal complexes (L:M = 4:1 in 3 and 4, L:M = 2:1 in 1 and 2) and the free ligand (L) which may due to the fact that the hetero-metal complexes have more bridged anions (SCN^-), conjugated subunits -[Hg(SCN)₂M]- and -[Hg₂(SCN)₄M₂]-. In addition, the results revealed that 2 PA response was much enhanced for the Zn(SCN)₂L₂ and two-photon fluorescence cell imaging experiment proved its potential application.