Ambi-Valence Taken Literally: Ruthenium vs Iron Oxidation in (1,1'-Diphosphinoferrocene)ruthenium(II) Hydride and Chloride Complexes as Deduced from Spectroelectrochemistry of the Heterodimetallic \dqMixed-Valent\dq Intermediates. Organometallics, (29)21:5511--5516, 2010. [PUMA: bridging chloride crystal cymene dichloro dimer diphosphinoferrocene diphosphinoferrocene;para diphosphinoferrocene;pentamethylcyclopentadienyl half heterodimetallic hydride hydride;ruthenium para prepn;mol ruthenium sandwich structure]