Reactions of fac(S)-[M(aet)3 ] (M = Rh III , Ir III ; aet = 2-aminoethanethiolate) with an excess of VCl 3 gave linear-type S-bridged trinuclear complexes [V III {M(aet) 3 } 2 ] 3ϩ (M = Rh III 1, Ir III 2). The ∆Λ isomers (1a(ClO 4 ) 3 and 2a(ClO 4 ) 3 ) were selectively crystallized and their structures were determined by X-ray diffraction. Both the complex cations consist of two terminal fac(S)-[M(aet) 3 ] units and a central vanadium atom, which is situated in an octahedral environment with a V III S 6 chromophore. The Ir complex 2a was also formed by using V IV OCl 2 instead of V III Cl 3 in a redox reaction, whereas the Rh complex 1a was not formed by a similar method. The optically active isomer (ΛΛ-1b) of the Rh complex was selectively obtained by using Λ-fac(S)-[Rh(aet) 3 ], and characterized by IR, UV-VIS absorption and CD spectra. All the obtained complexes exhibit a unique strong absorption band at ca. 18 × 10 3 cm Ϫ1 . Stability and reactivity relating to V-S bond cleavage for the complexes were investigated using UV-VIS absorption spectroscopic methods. These studies show first order decomposition or metal exchange. While 2a has weaker V-S bonds than 1a (from the X-ray analyses), the former is considerably more stable in water than the latter. Cyclic voltammograms of 1a and 2a in water show only irreversible oxidation and reduction waves including V IV/III and V III/II processes. The V() ions in the S-bridged trinuclear structures exhibit a lower magnetic moment (2.59 µ B for 1a and 2.27 µ B for 2a) at room temperature than the spin-only value for a d 2 electronic configuration. † Electronic supplementary information (ESI) available: Fig. S1 Absorption spectral change of ∆Λ-[V{Rh(aet) 3 } 2 ] 3ϩ (1a) upon addition of Co(); the curves show the spectra measured at 5 min intervals. See