Treatment of 1-(PPr2)-Pr-i-indene or 1-(PPr2)-Pr-i-2-NMe2-indene (1a) with elemental sulfur afforded 3-(Pr2P)-Pr-i(S)-indene or 1-(Pr2P)-Pr-i(S)-2-NMe2-indene (4a) in 81% and 85% isolated yield, respectively. Addition of 4a to [(COD)M(THF)(2)]+BF4- afforded the corresponding [(COD)M(kappa(2)-N,S-4a)](+) BF4- complexes (M = Rh, 5a, 76%; M = Ir, 5b, 59%; COD = eta(4)-1,5-cyclooctadiene), which were found to exhibit temperature-dependent NMR spectral features that were rationalized in terms of a dynamic process involving M-NMe2 dissociation, rotation about the indenyl-NMe2 bond, inversion at nitrogen, and re-coordination to M. Analysis of variable-temperature NMR data collected for 5a and 5b each yielded a value for Delta G(double dagger) of ca. 14 kcal/mol for this process. Exposure of 5a or 5b to NaN(SiMe3)(2) generated the corresponding (COD)M(kappa(2)-C,S-1-(Pr2P)-Pr-i(S)-2-NMe2-(C1-indenyl)) complex (M = Rh, 6a, 70%; M = Ir, 6b, 86%) in which the metal is incorporated into an M-C-P-S ring via coordination to the indenyl ring in an eta(1)-fashion, as well as to sulfur. Alternatively, complex 6b was prepared cleanly via lithiation of 4a followed by treatment with 0.5 equiv of [(COD)IrCl](2). The ability of 5a,b and 6a, b to mediate the addition of triethylsilane to styrene was also explored, and their performance was compared with that of Wilkinson's Catalyst ((PPh3)(3)RhCl) and Crabtree's catalyst ([(COD)Ir(PCy3)(Py)](+)PF6(-); Cy = cyclohexyl; Py = pyridine). Single-crystal X-ray diffraction data are provided for 4a, 2-NMe2-3-(Pr2P)-Pr-i(S)-indene (4b), 6a, and 6b.