Crystal Structure Of Mg Research Articles

Mg[Al(OCH 3) 2(CH 3) 2] 2·C 4H 8O 2. A novel coordination compound of a metal alkoxide and a donor molecule

The crystal structure of Mg[Al(OCH 3) 2(CH 3) 2] 2·C 4H 8O 2 has been determined by single-crystal X-ray diffraction methods. Two molecules crystallize in an orthorhombic unit cell with dimensions a = 13.42±0.02, b = 10.74±0.02, c = 7.30± 0.02 Å. The space groups is Pnnm. Full matrix least-squares refinement with magnesium and aluminum atoms anisotropic, resulted in a fianl R value of R 2=12.1%. The complex is an infinite polymer of Mg[Al(OCH 3) 2(CH 3) 2] 2 units held together by dioxane molecules. About the magnesium atom the point symmetry appears to be 2/ m, with the dioxane rings disordered about the two-fold axis. The metal atoms are bridged together by essentially sp 2 hybridized oxygen atoms, which are coplanar with the methoxy methyl groups and the metal atoms.

X-Ray, thermal, and Dehydration studies on Magnesium oxychlorides

X-ray, differential thermal analysis, and dehydration methods have been used to study the magnesium oxychlorides 3Mg(OH)2.MgCl2.8H2O and 5Mg(OH)2.MgCl2.8H2O formed at temperatures below 100 �C, and 2Mg(OH), . MgCl2.5H2O and 9Mg(OH)2.MgCl2.6H2O formed at temperatures at and above 100 'C. Lower hydrates of the 3-form exist with 5 and 4 molecules of water, results which differ from those of Feitknecht and Held (1944), Feitknecht (1953), and Wehner (1933). It 1s not clear from the new results whether the lower hydrates for the 5-form hare 5 and 3 or 4 and 3 molecules of water, but the latter seems the more likely ; the results of Feitknecht and Held suggested the former. For the 2- and 9-forms a lower hydrate with 2 molecules of water exists. In addition all forms have an anhydrous phase with the crystal structure of Mg(OH)2. The stability of all phases under natural atmospheric conditions is discussed.