Thulium compound with

In the case of thulium compounds TmSe and TmTe and YI3AI3, distinct multiplet structures due to divalent and trivalent thulium are seen in the 4f region [38]. The multiplet structure in TmTe is more distinct than in the case of TmSe in agreement with magnetic susceptibility data, (i.e.) magnetic moment of TmTe is smaller than that of TmSe. 

The substance Cleve called thulium was not pure thulium, but a compound of thulium combined with other elements. Pure thulium was not produced until 1910 by American chemist Charles James (1880—1928). 

Thulium compounds occur mixed with other rare earth compounds in minerals such as monazite, euxenite, and gadolinite. Monazite is about 0.007 percent thulium. 

Like many lanthanoids, pure thulium is made by treating its fluorine compound with calcium ... 

The shape of the curve shown in Figure 56 predicts a fairly high stability of neodymium and promethium dichlorides among the compounds with CN = 9 and dysprosium and thulium dichlorides among the compounds with CN = 7, that is, exactly those lanthanide dichlorides that (except PmCl2) not only were successfully synthesized but also were the subject of some physicochemical measurements that required heating to high temperatures. For instance, saturated vapor pressure of... 

Some nut trees accumulate mineral elements. Hickory nut is notable as an accumulator of aluminum compounds (30) the ash of its leaves contains up to 37.5% of AI2O2, compared with only 0.032% of aluminum oxide in the ash of the Fnglish walnut s autumn leaves. As an accumulator of rare-earth elements, hickory greatly exceeds all other plants their leaves show up to 2296 ppm of rare earths (scandium, yttrium, lanthanum, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). The amounts of rare-earth elements found in parts of the hickory nut are kernels, at 5 ppm shells, at 7 ppm and shucks, at 17 ppm. The kernel of the Bra2d nut contains large amounts of barium in an insoluble form when the nut is eaten, barium dissolves in the hydrochloric acid of the stomach. 

The brittle, silvery, shiny metal was long considered the last stable element of the Periodic Table. In 2003 it was unmasked as an extremely weak alpha emitter (half-life 20 billion years). Like thulium, there is only one isotope. Bismuth alloys have low melting points (fuses, fire sprinklers). As an additive in tiny amounts, it imparts special properties on a range of metals. Applied in electronics and optoelectronics. The oxichloride (BiOCl) gives rise to pearlescent pigments (cosmetics). As bismuth is practically nontoxic, its compounds have medical applications. The basic oxide neutralizes stomach acids. A multitalented element. Crystallizes with an impressive layering effect (see right). 

The only complexes of lanthanum or cerium to be described are [La(terpy)3][C104]3 175) and Ce(terpy)Cl3 H20 411). The lanthanum compound is a 1 3 electrolyte in MeCN or MeN02, and is almost certainly a nine-coordinate mononuclear species the structure of the cerium compound is not known with any certainty. A number of workers have reported hydrated 1 1 complexes of terpy with praseodymium chloride 376,411,438), and the complex PrCl3(terpy)-8H20 has been structurally characterized 376). The metal is in nine-coordinate monocapped square-antiprismatic [Pr(terpy)Cl(H20)5] cations (Fig. 24). Complexes with a 1 1 stoichiometry have also been described for neodymium 33, 409, 411, 413, 417), samarium 33, 411, 412), europium 33, 316, 411, 414, 417), gadolinium 33, 411), terbium 316, 410, 414), dysprosium 33, 410, 412), holmium 33, 410), erbium 33, 410, 417), thulium 410, 412), and ytterbium 410). The 1 2 stoichiometry has only been observed with the later lanthanides, europium 33, 411, 414), gadolinium, dysprosium, and erbium 33). 

In the thulium + chlorine system a number of such homologues is believed to exist in the region TmQ2+a. Thermal analysis suggests the existence of at least nine compounds in the range 0.04q = f5 < O.II2, i.e. Tm Q2n+i with 25.0 > 8.9. In this case... 

Compounds of divalent samarium, europium, and ytterbium are well-known. In recent years, lower halides of other lanthanides, such as neodymium 48), praseodymium 45, 49, 90), and thulium 4) have been obtained by reducing the trihalide with the metal. The corresponding reaction of thorium tetraiodide with thorium metal has led to the identification of two crystalline forms of Thl2 41, 91) it is unlikely that the Th ", or even Th ", ion is present in Thl2, but like Prl2, which is formulated as Pr " (r)2( ) (2), the compound is probably of the type Th " (r)2(2 ) 41). Certainly one crystal form is diamagnetic 41), suggesting the latter formulation. 

Lanthanide (III) Oxides. The lanthanide(III) oxides will be used to illustrate the present breadth of our most extensive knowledge of the chemical thermodynamics of lanthanide compounds. Cryogenic heat capacities of hexagonal (III) lanthanum, neodymium, and samarium oxides, together with those of cubic (III) oxides of gadolinium, dysprosium, holmium, erbium, and ytterbium, have been reported (90, 91, 195). In addition, those of thulium, lutetium, and a composition approaching that of cerium (III) oxide have also been determined, and five well-characterized compositions between PrOi.714 and PrOi.833 are currently under study (J93). 

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