Phenothiazine Cruciforms: Synthesis and Metallochromic Properties

• DOI: 10.1021/jo070922l
• Publication Date: 2007-08-10T12:00:58Z
• Authors: Martina Hauck; Jan Schönhaber; Anthony J. Zucchero; Kenneth I. Hardca...; Thomas J. J. Müller; Uwe H. F. Bunz
• Keywords: Trifluoromethanesulfonate; HOMO/LUMO; Triflic acid

We report the synthesis and characterization of five novel phenothiazine-containing cruciforms (5-9). The targets were prepared by a NaH-promoted Horner reaction tetraethyl(2,5-diiodo-1,4-phenylene)bis(methylene)diphosphonate with 10-hexyl-10H-phenothiazine-3-carbaldehyde. formed intermediary 3,3'-(1E,1'E)-2,2'-(2,5-diiodo-1,4-phenylene)bis(ethene-2,1-diyl)bis(10-hexyl-10H-phenothiazine) was reacted several different aromatic alkynes (1-tert-butyl-4-ethynylbenzene, N,N-dibutyl-4-ethynylaniline, 1-ethynyl-3-(trifluoromethyl)benzene, 1-ethynyl-3,5-bis(trifluoromethyl)benzene) to give corresponding cruciform fluororphores (XF). XFs fully characterized NMR IR spectroscopy then exposed trifluoroacetic acid as well metal triflates. show dramatic shifts in emission lesser extent absorption when magnesium triflate or zinc triflate. In case triflate, blue shift observed; contrast, addition results either quenching red-shifted emission. Due electronic situation, these display spatially separated frontier molecular orbitals, allowing HOMO LUMO be addressed independently ions. Phenothiazine may have potential array-type sensory applications for cations.