The chemistry and scope of thulium  and thulium compounds is reviewed here. We manufacture all these compounds and in most instances with these rare earth products , it is important to know the method of manufacture, solubilities, assays and trace impurities.

Rare earth compounds were named not because the individual rare earth elements are rare but because each individual rare earth element rarely exists as a single element but as a mixture of rare earth elements. Thulium was discovered by Swedish chemist Per Teodore Cleve in 1879 by looking for impurities in the oxides of other rare earth elements. Cleve started by removing all of the known contaminants of erbia. Upon additional processing, he obtained two new substances; one brown and one green. The brown substance was the oxide of the element holmium and was named holmia by Cleve, and the green substance was the oxide of an unknown element. Cleve named the oxide thulia and its element thulium after Thule, Scandinavia. In 1911, Theodore Richard Williams performed 15,000 recrystallizations of thulium bromate to obtain pure sample of the element and so to accurately determine its atomic weight.

Thulium was so rare that none of the early workers had enough of it to purify sufficiently to actually see the green color; they had to be content with spectroscopically observing the strengthening of the two characteristic absorption bands, as erbium was progressively removed. The first researcher to obtain nearly pure thulium was Charles James, a British expatriate working on a large scale at New Hampshire College in Durham NH. In 1911 he reported his results, having used his discovered method of bromate fractional crystallization to do the purification. He famously needed 15,000 "operations" to establish that the material was homogeneous.

High-purity thulium oxide was first offered commercially in the late 1950s, as a result of the adoption of ion exchange separation technology. Lindsay Chemical Division of American Potash & Chemical Corporation offered it in grades of 99% and 99.9% purity.

The composition of monozite ore is the basis for rare earth impurities found in thulium compounds and the level of impurities is directly related to the separation and source of these ores. Thulium is principally extracted from monozite (~0.007% thulium) ores found in river sands, through ion exchange. Newer ion-exchange and solvent-extraction techniques have led to easier separation of the rare earths, which has yielded much lower costs for thulium production. The principal sources today are the ion adsorption clays of southern China. Thulium is the most expensive of the rare earths truly due to its rarity.

Level of impurities:

 99.9%(REO)  1000ppm total rare earth oxide impurities

99.99%(REO)  100ppm total rare earth oxide impurities

99.999%(REO)  10ppm total rare earth oxide impurities

99.9999%(REO)  1ppm total rare earth oxide impurities

For a certificate of analysis for any of these products ordered contact: techservice@rareearthproducts.com

Thulium chloride, bromide and nitrates are isolated as the hexahydrates and are very soluble in water. Anhydrous halides are also available. Thulium acetate is somewhat soluble in water. (It is important to work with the manufacturer of your rare earth products because in the case of acetates the solubility varies widely depending on the method of manufacture and reaction conditions.

A new exciting thulium compound is thulium trifluoroacetate which is very soluble in water and has new uses as a catalyst in organic synthesis. Thulium oxalate, carbonate and sulfate are insoluble in water and exist as a defined hydrate. These compounds can also be hydrated.

Another example of purchasing rare earth compounds from a known manufacturer is thulium fluoride. The rare earth fluorides are used in advanced material  films, lens and glasses. In virtually all applications the fluoride should be carbonate free. Rare Earth Products, Inc. uses a proprietary process to make carbonate free rare earth fluorides.

Rare Earth Products, Inc makes the most extensive list of rare earth metal beta diketonates. These organometallic compounds are used for MOCVD, spin coating, catalysts and NMR shift reagents to name a few advanced applications. The compounds offered include rare earth metal complexes with :

acetylacetonate or 2,4-pentanedionate ACAC

 hepatfluorodimethyloctanedionate FOD

hexafluoroacetylacetonate HFAC

tetrametylheptanedionate TMHD

  trifluroacetylacetonate TFAC

chiral ligands OPT etc

 Most of these compounds are used because of  the physical vapor pressure, volatility and organic solvent solubility. Contact our technical service department to get physical data such as melting points, sublimation temperatures,  solubility,  boiling points,  etc - techservice@rareearthproducts.com.

Rare Earth Products, Inc also manufactures the organic soluble compounds thulium 2-ethylhexanoate and thulium cyclohexanebutyrate. These metal organic  compounds are soluble in organic solvents. We can also custom synthesize various rare earth  compounds by adding various ligands, dehydrating and coordinating various organic solvents to enhance non polar solubility. Contact techservice@rareearthproducts.com.

The intermetallics thulium sulfide, thulium selenide and thulium telluride are available upon request. Thulium trifluoromethanesulfonate or thulium triflate is available and useful as a Friedel -Crafts catalyst as the anhydrous salt or the hydrate. A new compound thulium thenoyltrifluoroacetonate is used as a thermal laser dye.