PROTECTIVE COATINGS FOR MAGNESIUM ALLOYS. PART 3. COORDINATION CHEMISTRY OF THE MAGNESIUM ION
Abstract
The coordination chemistry of magnesium ions was studied with respect to neutral, but polar, unidentate ligands in the presence of various donor anions. Complexes of the type (MgLn)A2 were prepared. Chemical analysis, infrared spectral data, and electrical conductivity were used to assign the structure of the isolated products. The ligands L were dimethyl sulfoxide, pyridine N-oxide, triphenylphosphine oxide, and tripenylarsine oxide. The value of n depended on the size of the ligand and the nature of the anion A, which was varied from a weak donor (perchlorate ion) to strong donors (acetate or methacrylate ions). The maximum value of n was six when the ligands were dimethyl sulfoxide or pyridine N-oxide and the anions were perchlorate ions. The bulkier ligands, triphenylphosphine oxide and triphenylarsine oxide, were sterically restricted to only four ligands per magnesium ion even when the anions were perchlorate ions. The methacrylate ions successfully competed for first coordination-sphere positions about the magnesium ions; the weak-donor ligands, dimethyl sulfoxide and pyridine N-oxide, were readily displaced. The infrared spectral data indicates that the methacrylate anions act as bidentate ligands; however, the stoichiometry of some of the complexes can only be explained if the acetate and methacrylate anions function as unidentate ligands.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 02, 1967
- Accession Number
- AD0649323
Entities
People
- D. L. Venezky
Organizations
- United States Naval Research Laboratory