2′-bipyridine, thp= tris (hydroxymethyl) phosphine] is both strongly luminescent and
photoactive toward carbon monoxide release. It is stable in aerated aqueous media, is
incorporated into cells from the human prostatic carcinoma cell line PPC-1, and shows no
apparent cytotoxicity. Furthermore, the solvated Re (I) photoproduct of CO release (2) is also
luminescent, a feature that allows one to track the transformation of 1 to 2 inside such cells …