Electrospray ionization mass spectrometry of rhenium(I) bipyridyl complexes

The electrospray ionization mass spectrometry (ESI-MS) of a series of rhenium(I) bipyridyl complexes [(4,4'-(COOEt)(2)-bPY)Re(CO)(3)RPF6], where bpy is 2,2'-bipyridine and R is pyridine, 4-methylpyridine, 4-hydroxypyridine, 4-aminopyridine or 10-(4-picolyl)phenothiazine (py-PTZ) was studied. The dissociation of the ligands (R) forms the fragment of [(4, 4'-( COOEt)(2)-bpy) Re (CO)3](+) at different voltages of in-source collision induced dissociation (CID). The dissociation tendency is in an order: pyridine > 4-methylpyridine > 4-hydroxypyridine > 4-aminopyridine > py-PTZ. It might be used to deduce the stability of these complexes when they are used as photosensitizers in solar cells.