Lipophilic Re(CO)3pyca complexes for Mid-IR imaging applications

Abstract

Several Re(i)pyca conjugates incorporating long aliphatic amines have been synthesized through a one-pot methodology. The compounds have been fully characterized, and seven compounds have been structurally elucidated by single crystal X-ray diffraction. The C14 variant was probed as a potential organometallic IR dye. Large unilamellar vesicles were generated with DOPC and the C14 compound and we observed incorporation of the rhenium complex as observed by FTIR microscopy.

Fig. 1

The structures of compounds 1b, 3a, and 5b with 35% thermal ellipsoids. Hydrogen atoms have been omitted for clarity.

Fig. 2

UV-visible spectra for compounds 5a and 5b in DCM.

Fig. 3

a) IR microscope image of control vesicles containing 100 mol % DOPC. Zoomed in region shows the single vesicle the IR spectrum was taken of. b) IR microscope image of Re(I) containing vesicles with 95 mol % DOPC, and 5 mol % (by Re(I) content) of compound 5a. Zoomed in region shows the single vesicle the IR spectrum was taken of c) FTIR spectra in transmittance mode of the single control vesicle and a vesicle with Re(I). Zoomed in region shows M-CO stretches.

Scheme 1.

Synthetic route for preparation of the compounds 1a-5a, and 1b-5b.