Tropolonate complexes of Ru(II), Ru(III), and Os(II) with hinokitiol, also termed beta-thuljaplicin, or 4-isopropyltropolone, readily formed by chloride and triarylphosphine substitution in RuCl2(PPh3), and MHCI(CO)(PR3)(3) (M = Ru, R = Ph; M = Os, R = Ph and p-tolyl). The resulting colorful complexes have variable and strong charge transfer bands and also have a surprising combination of stereochemical selectivity and lability. For the Os(II) d(6) examples, the tropolone chelate has a fluxionality with a barrier of only 90 kJ/mol for the R = aryl examples, as determined by variable-temperature P-31 NMR. Chlorination with N-chlorosuccinimide results in MCl(CO)(hino)(PPh3)(2) (M = Ru and Os). Together these results quantify the fluxionality of this important chelate which in turn has consequences for its biochemistry.