POLYNUCLEAR HYDROXO COMPLEXES.
Abstract
The hydrolytic condensation reactions of several organometallic compounds were studied in detail. Among the systems examined were (CH3)2Sn(IV), (CH3)2Ga(III), (CH3)2Au(III) and (CH3)3Pt(IV). It was found that the presence of alkyl groups in the first coordination sphere of metal ions labilizes the remaining ligands to a very great degree. This is especially apparent with the classically inert Pt(IV) species where the average lifetime of a bound water molecule of (CH3)3Pt(OH2)3(+) was found. Both the exchange rate and the hydration number of this cation were determined with Oxygen-17 n.m.r. The ion (CH3)2Au(+) was shown with Raman spectroscopy to have the cis structure in aqueous solutions. The thermodynamics of the condensation reaction were examined in solution at 25C, and the end product was found to be ((CH3)2AuOH)4. A complete crystal structure determination was made for this compound. Because the lability of these complexes leads to very fast reactions, the rates were too high to be determined using flow systems. The hydrogen isotope effect on the acid dissociation of (Co(NH3)5OH2)(+3) was examined and found to be normal, and the acid dissociation of coordinated water molecules does not seem to give rise to anomalous isotope effects. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1968
- Accession Number
- AD0680027
Entities
People
- R. Stuart Tobias
Organizations
- University of Minnesota