The reactivity, structures, and NMR spectroscopy of compounds relevant to asym. transfer hydrogenation, Cp*RhCl(S,S-4-RC6H4SO2NCHPhCHPhNH2) (Cp* = η5-C5Me5, S,S-2a R = Me, S,S-2b R = tBu, S,S-2c R = F), were studied. 1H/15N HMQC NMR spectra of 2a-2c were recorded with 15N in natural abundance making use of the coupling to the C5Me5 protons; the coupling constants JRhN were ca. 15 and 20 Hz for the amino and amido nitrogens, resp. 1H/103Rh NMR spectra of 2a and 2c were recorded similarly. The chloride ligand in S,S-2a is very labile; reaction with CO afforded the cationic complex [Cp*Rh(CO){C(O)N(Ts)CHPhCHPhNH2}][Cl] (3a, Ts = 4-MeC6H4SO2) as a mixture of diastereomers, S,S,RRh and S,S,SRh, with opposite chirality at Rh; reaction with tBuNC gave [Cp*Rh(CNtBu)(S,S-TsCHPhCHPhNH2)][PF6] (4a), and reactions with LiBr and KI gave Cp*RhBr(S,S-TsNCHPhCHPhNH2) (6a) and Cp*RhI(S,S-TsNCHPhCHPhNH2) (7a), resp. Complexes S,S-2c, S,S-6a, and S,S-7a were characterized by x-ray crystallog.; the amino N-Rh bond is significantly shorter than the amido N-Rh bond in all cases (difference Δr 0.058(2), 0.085(6), and 0.046(4) Å, resp.), and the complexes all possess intramol. NH···X (X = Cl, Br, I) H bonds. The reaction of 2a with formic acid results in complete displacement of the chelating ligand and the formation of dinuclear [{Cp*Rh}2(μ-H)(μ-Cl)(μ-HCO2)][BPh4] (5a), which was also characterized crystallog. Reaction of 2c with AgOTf (OTf = CF3SO3) gave [Cp*Rh(OH2)(4-FC6H4SO2NCHPhCHPhNH2)][OTf] ([8c·H2O][OTf]) or [Cp*Rh(4-FC6H4SO2NCHPhCHPhNH2)]2[OTf]2 ([8c]2[OTf]2) depending upon the conditions employed. ([8C·H2O][OTf]) was characterized by x-ray crystallog., and the structure showed that both CHPh centers in the ligand had been racemized, converting the S,S isomer of the starting material into a mixture of both R,R and S,S isomers.