| Popis: |
In M LiCl at 25 °C, Co(NH 3 ) 5 Br 2+ reacts with TiOH 2+ with k 2 = 0.18 M −1 s −1 . Co(NH 3 ) 5 F 2+ reacts with Ti 3+ with K 2 = 1 × 10 3 M −1 s −1 . For Co(en) 2 (H 2 O)(OH) 2+ ions, rate constants for reaction with Ti 3+ are 50 M −1 s −1 for trans and 20 M −1 s −1 for cis : for the same oxidants, rate constants for reaction with TiOH 2+ are 3 × 10 3 M −1 s −1 for cis and 4 × 10 3 M −1 s −1 for trans . The reactions with rate constants near 10 3 M −1 s −1 are interpreted as substitution-limited inner-sphere processes. Bromide ion is a poor bridging ligand for Co(III)-Ti(III) electron transfers while hydroxide ion and (especially) fluoride ion are efficient bridging ligands; cross-bridge interactions are more important for reactions of Ti(III) than for reactions of Cr(II) |
