Pentamolybdobis ethylphosphonate

Ammonium salt, (NH4)4[(C2H5P03)2MosOi5] Ethylphosphonic acid (0.88g, 8 mmol) (Aldrich) is dissolved in 25 mL of water containing 4.83 g of sodium molybdate dihydrate (20mmol). The solution is acidified with 4mL of 6MHC1 (24 mmol) and then boiled for 15-20 min. To the reaction solution is added ammonium chloride (0.86g, 16 mmol) dissolved in 3mL of warm water. The volume is reduced to 15 to 20 mL by heating, and the resulting solution is filtered while hot. When the filtrate is allowed to crystallize in the air, chunky crystals are formed in a few days. They are collected, washed with 2mL of cold water, and air dried. Yield 3.7 g (92%). This product is recrystallized from the minimum of hot water. 

Tetramethylammonium sodium salt [(CH3)4N]3Na[(C6H5P03)2Mo50 5]-6H2O Sodium molybdate dihydrate (6.05 g, 20 mmol) and phenylphosphonic acid (1.58 g, lOmmol) are dissolved in 30mL of water. The mixture is acidified with 5 mL of 6 M HCI (30 mmol) and then boiled for 15-20min. Tetramethylammonium chloride (2.2 g, 20 mmol) dissolved in 3mL of water is added to the reaction solution. After nitration, the solution is concentrated to 

Tetramethylammonium salt, [(CH3)4N]2[(NH3C6H4CH2P03)2Mo50is]-4H2O This salt is obtained from a reaction solution prepared as described for the ammonium salt. When tetramethylammonium chloride (0.44 g, 4mmol) dissolved in 3mL of water is added to the filtrate, a white powder is formed. After the suspension is stirred for 5-10 min at room temperature, the powder is removed by filtering, washed quickly with 2mL of ice-cold water, and then air dried. Yield 1.21 g (92%). 

These heteropoly salts are all white solids with similar IR spectra and well-resolved medium to strong peaks at 1130-970 cm (P—O stretch) and 950-890 and 730-660cm (M—O terminal and bridging stretches). The ammonium and tetramethylammonium (sodium double) salts are soluble in water tributylammonium pentatungstobis(phenylphosphonate) is insoluble in water and methanol but soluble in acetonitrile, /V./V-dimethylformamide, dimethyl sulfoxide, and dichloromethane. Proton NMR spectra of the 

15-20tnL by boiling. As it is transferred to a Petri dish in a shallow layer and allowed to evaporate slowly with a loose cover, the compound is precipitated as thin, platelike crystals. The crystals are collected by filtration, washed twice very quickly with cold water and then dried in the air. Yield 6.4 g (92%). 

Ammonium salt, (NH4)[(NH3C6H4CH2P03)2MosOi5] 5H20 Sodium molybdate dihydrate (1.21 g, 5 mmol) and (p-aminobenzyl)phosphonic acid (0.37 g, 2 mmol) (Sigma) are dissolved in 70 mL of water. To this solution is added 2.0 mL of 3Af HCl (6 mmol). The solution is boiled for 30 min and then filtered. When ammonium chloride (0.22 g, 4.2 mmol) dissolved in 2mL of water is added to the reaction solution, and the mixture is allowed to evaporate slowly at room temperature, a pale yellow crystalline powder is formed. It is collected, washed twice, quickly, with 1 mL of cold water, and then air dried. Yield 1.15 g (94%). 

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Mo,N,0. P.C,H 5HjO, Pentamolybdobis-[(2-aminoethyl)phosphonate](4 -), sodium tetramethylammonium dihydrogen, pentahydrate, 27 126 Mo,N40,P,CjH2. 2H20, Pentamo-lybdobis(methylphosphonate)(4 - ), tetraammonium, dihydrate, 27 124 Mo,N40.,P.C4H , Pentamolybdobis-(ethylphosphonate)(4-), tetraammonium, 27 125... 

Pentamolybdobis(ethylphosphonate>-(4—), tetraammonium, 27 125 P2Mo,N402,C,2H26 5H2O,... 

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