Magnesium complexes hydrates

Magnesium compounds hydrate readily, and anhydrous magnesium halides form addition compounds with aldehydes, ketones and ethers, which are structurally similar to those of Be. Otherwise its complexes are few and unstable. 

These can be prepared by electrolytic oxidation of chlorates(V) or by neutralisation of the acid with metals. Many chlorates(VII) are very soluble in water and indeed barium and magnesium chlorates-(VII) form hydrates of such low vapour pressure that they can be used as desiccants. The chlorate(VII) ion shows the least tendency of any negative ion to behave as a ligand, i.e. to form complexes with cations, and hence solutions of chlorates (VII) are used when it is desired to avoid complex formation in solution. 

Many ionic compounds contain what used to be referred to as water of crystallization . For example, magnesium chloride can exist as a fully hydrated salt which was formerly written MgCla.bHjO, but is more appropriately written Mg(OH2)eCl2, since the water molecules occupy coordination sites around the magnesium ions. This is typical. In most compounds that contain water of crystallization, the water molecules are bound to the cation in an aquo complex in the manner originally proposed by Alfred Werner (1866-1919) in 1893 (Kauffman, 1981). Such an arrangement has been confirmed in numerous cases by X-ray diffraction techniques. 

Both humic acids and fulvic acids have a strong affinity for particulate and crystalline substances possessing oxygen atoms at their surfaces and they have been reported to bring about the dissolution of iron phosphate, calcium phosphate (61), uranium dioxide (65), hydrated magnesium alumino-silicates (66) and limonite, a complex mixture of hydrated ferric oxides (67). 

It is hydrated complex of hydroxy magnesium aluminate. It initially reacts with acid and releases Al(OH)j which then reacts more slowly. It is a good antacid, with prompt and sustained neutralizing action. 

Anhydrous hydrazine dssolves many salts, thus, 100 parts of solvent at 12-5°-13° dissolve 12-2 parts of sodium chloride 8 5, of potassium chloride 56-4, of potassium bromide 135-7, of potassium iodide 26-6, of sodium nitrate 21-7, of potassium nitrate and 814, of barium nitrate. The hydrazine seemed to unite with sodium chloride with a warm soln. of ammonium chloride, ammonia is evolved, and in the cold, there seems to be a state of equilibrium a complex salt seems to be formed with lead nitrate. An aq. soln. of hydrazine hydrate also dissolves a number of salts, potassium bromide and iodide, ammonium sulphate, potassium cyanide, barium nitrate, magnesium sulphate, etc. According to T. W. B. Welsh and H. J. Broderson, the solubility of the metal haloids seems to... 

Being very strong bases, organometallic compounds are capable to start the polymerization (7, 12, 30, 51, 62). If organomagnesium compounds are used, the interaction of magnesium cations with lactam anions can probably reduce the dissociation of the salt analogous the basic character is certainly weakened in lactam complexes formed by addition of hydrated oxides of Ti, Zr, Hf, Th or Ce (48). 

Magnesium-vermiculite also forms monolayer hydrates with basal-plane spacings of 1.163 and 1.153 nm [23]. These hydrates are distinguished by the configuration of the Mg2+ solvation complexes (outer-sphere surface complexes) in them. The hydrate with the larger basal-plane spacing contains Mg2+ in the centers of flattened tetrahedra formed by water molecules the other clay hydrate contains Mg2+ at the apex of a pyramid whose base comprises three water molecules. 

---