2-{(E)-2-[(3E)-2-Chloro-3-{(2E)-2-[1,1-dimethyl-3-(3-phenylpropyl)- 1,3-dihydro-2H-benzo[e]indol-2-ylidene]-ethylidene}cyclohex-1-en-1-yl] ethenyl}-1,1-dimethyl-3-(3-phenylpropyl)-1H-benzo[e]indolium Iodide

In four synthetic steps we successfully prepared a red-shifted heptamethine cyanine dye (lambda(max) = 825 nm in methanol) that could be very useful for biochemists and bioanalytical chemists for probing lipophilic environments, including the hydrophobic pockets of enzymes. The heptamethine dye structure was characterized by various spectroscopic techniques including H-1-NMR, C-13-NMR and high-resolution accurate mass spectroscopy (HRMS). We have also shown the hydrophobicity spectrally by varying methanol/water ratios and observing corresponding absorbance and fluorescence spectral changes.