Ammine hydroxo-bridged complexes

Ammine hydroxo-bridged complexes, absorption spectra of, 32 71 Ammine-monocyanide complexes CN- stretching frequencies in, 12 388 Ammonia... 

Analysis of the products of these cleavage reactions has often served as proof of the structures of the polynuclear species. Cleavage of hydroxo-bridged complexes of nuclearity higher than two will in most cases yield at least two different mononuclear species. Identification of these species and determination of the relative ratio in which they are formed reduce the number of possible bridged skeletons greatly, and the studies of polynuclear ammine and amine chromium(III) made by Andersen et al. (mentioned in Section IV) provide many examples of this, one of which is shown in Eq. (48) above (see also Section II,A). 

Absorption Spectra of Some Hydroxo-Bridged Ammine and Amine Complexes in Aqueous Solution... 

The data in Table XXXV show that common features for these ammonia and amine complexes are very fast isomerization between the cis and trans isomers of the diaqua species and the fact that the trans diaqua isomers are generally more stable than the cis isomers. In the ammine system the activation parameters for k2 and k 2 are consistent with an isomerization process at cobalt(III), but it is at present not clear how this occurs. It need not be a simple cis-trans isomerization occurring at one of the Co(III) centers, but might involve the participation of both metal centers. The isomerization reaction may proceed via intramolecular proton transfer between a water ligand and one of the two hydroxo bridges with simultaneous bridge cleavage and formation... 

In addition to the numerous mononuclear ammine complexes of Co111, there are a number of polynuclear ammine complexes in which hydroxo (OH-), peroxo (02 ), amido (NHJ), and imido (NH2-) groups function as bridges. Some typical complexes of this class are... 

---