Dysprosium Chloride Research Articles

Azaoxa Macrocyclic and Acyclic Complexesof Lanthanides

The template reactions of 2,6-diacetylpyridine with 3,6-dioxaoctane-1,8-diamine in the presence of dysprosium(III), thulium(III) and lutetium(III) chlorides and erbium(III) perchlorate produce the complexes of 15-membered macrocyclic ligand with an N3O2 set of donor atoms as a result of the [1+1] Schiff base cyclocondensation. In contrast, analogous reactions involving the lighter lanthanide ions (lanthanum(III), samarium(III) and europium(III)) yield the acyclic complexes with terminal acetylpyridyl groupings as products of the partial [2+1] condensation. The complexes were characterized by spectral data (IR, UV-VIS, 1H NMR, MS), and thermogravimetric and elemental analyses.

Identification of the dysprosium(III) chloride solvate DyCl3(THF)3.5: crystal structure of the ion pair [trans-DyCl2(THF)5] [trans-DyCl4(THF)2

Abstract Treatment of DyCl3(H2O)6 with thionyl chloride in the presence of tetrahydrofuran provided colourless crystals of DyCl3(THF)3.5, subsequently identified as the ionic salt [trans-DyCl2(THF)5] [trans-DyCl4(THF)2] by an X-ray diffraction study. The dysprosium atom in the monocation is seven coordinate with the trans-DyCl2 unit [Dy-Cl, 2.624(5)A˚] surrounded by five tetrahydrofuran molecules (Dy-O, mean 2.41(2)A˚) in a regular pentagonal bipyramidal geometry. For the anion the dysprosium atom is six coordinate with an octahedral geometry comprising four equatorial chlorine atoms (Dy%z.sbnd;Cl, mean 2.642(5)A˚) and two axial tetrahydrofuran molecules (Dy-O, 2.41(2)A˚).

The Isotope Effect on the Internal Cation Mobility of Molten Dysprosium Chloride

The isotope effect on the internal mobility of the dysprosium ion in molten dysprosium chloride has been measured from 973 to 1073 K by countercurrent electromigration. Heavier Dy isotopes have been enriched toward the anode. The mass effect defined by μ = (Δu/uDy)/(ΔM/MDy) has been calculated to be −0.032 ± 0.002, where Δu is the difference in the mobilities of M (mass number) = 160, 161, 163, or 164 with reference to that of M = 162. A comparison of this value with those previously determined for other molten metal chloride systems suggests that the main electrically conducting species containing Dy is the trivalent cation and not the species shown to exist in the melt by other techniques.

Recovery of amino acids at the distal ileum for determining apparent and true ileal amino acid digestibilities in growing pigs fed various heat-processed full-fat soybean products

Ten crossbred gilts fitted with simple T-cannulas at the distal ileum were used to determine the apparent and true ileal amino acid digestibilities in five different soybean products: extruded, jetsploded, micronized, or roasted full-fat soybeans (FFSB) and soybean meal (SBM). The gilts with an average initial body weight of 36 kg were fed the different diets according to a replicated 5 x 5 Latin square design. Gilts were fed twice daily at 0800 and 1830 at 2.6 times maintenance energy requirement. All diets were cornstarch-based and formulated to contain 16% CP from one of the five soybean products. The recovery of endogenous lysine at the distal ileum was determined using the homoarginine technique. This technique involved the guanidination of dietary lysine to homoarginine, to allow for a differentiation between undigested dietary lysine, represented by homoarginine, and endogenous lysine in the digestive tract of pigs consuming diets that contain guanidinated proteins. Chromic oxide and dysprosium chloride were included as indigestible markers in the normal and homoarginine diets, respectively. True digestibilities were only determined with the five gilts of one Latin square. Ileal digesta were collected for 24 h on d 8 and 10 of each 10-d experimental period. The apparent ileal protein digestibility was higher in SBM than in other soybean products (P < .05). In the heat-treated FFSB, the apparent protein digestibility varied between 69.0 and 81.6%. Recovery of endogenous lysine was affected by the diet (P < .01) and varied between 1,329 and 2,448 mg/kg of DM intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Crystal structure of the Nd, Gd, and Dy sandwich complexes involving 8-membered macrocyclic phenylsiloxanolate ligands

An X-ray structural investigation of the interaction products of anhydrous trivalent neodymium, gadolynium, and dysprosium chlorides with sodium phenylsiloxanolate was carried out. The synthesized compounds with the general formula Na6[PhSiO2]8M4(μ4-O)[O2SiPh]8 · 10EtOH · 8H2O (M = Nd, Gd, Dy) were found to be isomorphous isostructural sandwich complexes. The macrocyclic octaphenyloctasiloxanolate ligands in the complexes have anall-cis-configuration and are arranged in co-axial antiparallel pairs and coordinate the square planar groups of the four Nd3+, Gd3+, or Dy3+ ions stabilized by an additional central μ4-bridging O2− ligand. Six Na+ counterions form the outer coordination sphere of the complexes such that four of them coordinate the siloxane macrocycle O atoms in pairs in analogy with crown-ether complexes.

Studies on the Biological Effects of Rare Earth Elements. V. Relationship between the Concentration of Rare Earth Elements and 9 Minerals in Various Organs in the Rat after Intravenous Administration of Dy, Eu, Yb and Y by Low or High Dose.

The relationships of the concentration of rare earth elements (REEs) and 9 minerals (Ca, Mg, P, Fe, Na, K, Zn, Cu and Mn) in the liver, kidney, spleen, lung, femur and whole blood were investigated in the male rats of Wistar strain. High or low dose of dysprosium chloride (DyCl3), europium chloride (EuCl3), ytterbium chloride (YbCl3) and yttrium chloride (YCl3) was administered intravenously from the caudal vein. High doses were 20 mg/kg (as REEs) for Dy, Eu and Yb or 10 mg/kg (as REEs) for Y, and low doses were 10 mg/kg (as REEs) for Dy, Eu and Yb or 5 mg/kg (as REEs) for Y. These doses were similar to μmol of each REE per rat. The contents of REEs and 9 minerals in the liver, kidney, spleen, lung, femur and whole blood were estimated by the wet digestionICP-AES method 1 day after the intravenous administration. Results were as follows : 1) The concentrations and distribution rates (% of dose) of REEs in the liver, spleen and lung increased by several times in the rats administered high dose of Dy, Eu and Y [Dy (H), Eu (H) and Y (H)] contrary to the decrease of distribution rate of REEs in the kidney. Distribution rate did not change by dose in the rats administered Yb. 2) Ca concentrations in the liver, spleen and lung increased by several or several decade times in the rats of Dy (H), Eu (H) and Y (H) groups. There were the tendency of Na concentration to be higher and K concentration lower in these rats. Zn concentration in the liver increased slightly by REEs administration. There were no effects of REEs administration otherwise. 3) There were strong positive correlations (p<0.001) between REEs and Ca concentrations in the liver, spleen and lung in the rats administered Dy, Eu or Y ; Ca concentration increased proportionally to REEs concentration. There was no correlation between Ca and Yb concentration. Therefore, it was suggested that there might exist the threshold of REEs dose for the increase of Ca concentrations proportionally to REEs concentrations in the liver, spleen or lung, and the appearence of Yb toxicity might be different from other 3 REEs (Dy, Eu and Y) toxicities.

Studies on the Biological Effects of Rare Earth Elements. II. Distribution and the Histlogical Effects of Dy, Eu, Yb and Y in the Rat after Intravenous Administration.

Low dose (10mg/kg as rare earth elements) or high dose (50 mg/kg as rare earth elements) of 4 kinds of rare earth element solutions, i. e. dysprosium chloride (DyCl3), europium chloride (EuCl3), ytterbium chloride (YbCl3) and yttrium chloride (YCl3), were administered intravenously from the caudal vein of rat, and the distribution and the histological change in the tissues were investigated at the 8th days after the administration. The rusults were as follows : 1) The administered rare earth elements were mainly accumulated in the liver, spleen and bone. The concentrations of rare earth elements in the kidney, pancreas and heart were low. No rare earth elements was detected from the muscle and whole blood. 2) More than 3 times of amounts of the rare earth elements were accumulated in the spleen of rats when administered low dose of YCl3, and higher amounts of the rare earth elements were accumulated in the bone of the rats administered YbCl3 compared to the rats administered other rare earth elements of low dose. On the contrary, the difference in the pattern of accumulation in the various organs was not observed when administered high dose. The distribution (% of dose) of the rare earth elements in the spleen tended to elevate but those in the bone tended to be lower in the bone of the rats administered high dose. 3) No obvious change was observed in the liver of the rat administered low dose. The deposition of the brown substance or xenobiotics was observed in the spleens of the rats administered low dose of DyCl3 and YCl3. The reaction of macrophage was observed in the spleen of the rats administered low dose of YCl3. 4) The formation of xenobiotic glanuloma was observed in the spleen when the rats administered high dose of rare earth elements. Therefore, when the chlorides of Dy, Eu, Yb and Y were administered to the rats intravenously, the administered rare earth elements accumulated mainly in the liver, spleen and bone and the formation of glanuloma was observed in the spleen when high dose administered.

Studies on the Biological Effects of Rare Earth Elements. III. Fate of Chlorides of Dy, Eu, Yb and Y in the Rat after Intravenous Administration.

Four kinds of rare earth element solutions [(10mg/kg as rare earth elements), i. e. dysprosium chloride (DyCl3), europium chloride (EuCl3), ytterbium chloride (YbCl3) and yttrium chloride (YCl3)], were administered intravenously from the caudal vein of rat. The excretion into the feces and urine, and the concentration and the distribution (% of dose) of rare earth elements in the whole blood, liver, kidney, lung, spleen and bone were investigated as a function of time. The results were as follows : 1) The administered rare earth elements were excreted gradually into the feces for 7d. The excretion rate accounts for 5.4-18.4%. The excretion of Y was lower than the other 3 kinds of rare earth elements. No rare earth elements were detected from the urine. 2) Rare earth elements in the whole blood disappeared within 1d. Y in the whole blood disappeared within 4h after the administration. 3) The major organs for accumulation of the administered rare earth elements were liver, spleen and bone. The distribution (% of dose) of rare earth elements in the liver was the highest level at 8h to 2d after the administration, then decreased gradually. The levels of distribution of rare earth elements in the kidney and lung were low during the experimental period. The distributions of Dy, Eu and Yb in these organs increased till 1d after the administration, and then almost unchanged. On the contrary, the distribution of Y in the spleen was larger than those of Dy, Eu and Yb, and increased as a function of time during the experimental period. The distribution of rare earth elements in bone increased gradually as a function of time. The highest level was observed in the case of Yb administration. Therefore, it was suggested that the rare earth elements in the blood disappeared within 1d, and that the rare earth elements were accumulated mainly in the liver, spleen and bone and retained for a long time.

Nutritive value of canola seed for young pigs

Canola seed (CS) ( Brassica campestris cv. Tobin), either raw and ground or ‘jet-sploded’, was given to weanling pigs in isonitrogenous (20% crude protein) diets based on wheat, barley and soya bean meal (SBM). In Experiment I, 160 4-week-old weaned pigs were assigned to seven dietary treatments, a SBM diet and six diets in which 7.5, 15 or 30% ground CS was included in raw or jet-sploded form. In Experiment II, 65 4-week-old pigs were allotted to one of five diets, a SBM diet or diets supplemented with 15 or 30% ground raw or jet-sploded CS. To each of the five diets, the inert marker dysprosium chloride was incorporated for digestibility studies. In Experiment I, increasing the dietary levels of raw ground CS from 0 to 15% of the diet had no significant effect on growth rate, feed intake or feed-to-gain ratio. The inclusion of CS in jet-sploded form significantly ( P < 0.05) reduced growth rate. In Experiment II, the SBM control diet was significantly superior ( P < 0.05) in the digestibility of dry matter, energy, crude protein and lysine to the other four diets.

Ileal and faecal energy digestibility coefficients of full-fat canola seed for swine

Experiments were conducted to determine the ileal and faecal apparent digestible energy (ADE) value of canola seed (CS) for pigs. In the first experiment, five barrows were cannulated at the ileum and given purified diets containing CS with dysprosium chloride as an inert marker. Digestibility of crude protein and lysine were also determined. In Experiment 2, ADE values for CS were determined using the mobile nylon bag technique (MNBT). The true metabolizable energy (TME) of CS was determined using adult cockerels to determine its value as a predictor of ADE for swine. The faecal ADE value for CS was 19.7 MJ kg −1 DM. The ileal ADE value for CS was 17.6 MJ kg −1 DM. The MNBT ADE value for CS was 17.1 MJ kg −1 DM. The TME value for CS was 19.93 MJ kg −1 DM. The ADE value of CS predicted from the TME value for CS was 16.85 MJ kg −1 DM, which was 4.2 and 14.5% lower than the ADE values derived by ileal and faecal collection methods. The linear equation determined from regression analysis that was used to predict ADE from TME was: Y=3.895-0.65X (r=0.91; d.f.=4; SEM=0.38, < 0.01) where X is TME and Y is the ADE value. Faecal digestibility coefficients for dry matter, energy, protein and lysine of CS were 71.7, 82.3, 62.6 and 75.9%, respectively, and those values determined by the ileal method were 59.7, 75.7, 69.5 and 72.1%, respectively.

Hydration of the Dy3+ ion in dysprosium chloride solutions determined by neutron diffractiona)

The coordination of water molecules about the Dy3+ ion in a 2.38 m DyCl3 in D2O solution has been determined by neutron scattering. The information was obtained using samples that were identical except for the isotopic species of the Dy3+ ions. The experiment yields the distribution of the deuterium and oxygen atoms in the first hydration shell. Each Dy3+ ion is surrounded by 7.4±0.5 water molecules. The dysprosium–oxygen separation is 2.37 Å and the dysprosium–deuterium separation is 3.04 Å. The cation–water molecule orientation is closer to planar than that which has generally been observed in other aqueous solutions.

Inefficiency of triplet energy transfer from ketones to trivalent rare earth ions

Abstract : It is shown that trivalent samarium, europium, terbium, dysprosium, and erbium chlorides are only 1-2% as effective as conjugated dienes at quenching the triplet state photoelimination of para-methoxyvalerophenone and the triplet state photoreduction of benzophenone. Maximum rate constants for energy transfer from the triplet excited ketones to the rare earth ions is (10 to the 8th power)/M/sec in solvents such as methanol and aqueous acetic acid. This conclusion refutes the former common assumption that such energy transfer was diffusion-controlled. It is postulated that the tight solvation of the metal ions prevents effective overlap of donor and ionic orbitals and thus decreases the exchange interaction necessary for energy transfer. (Author)

Pharmacology and toxicology of dysprosium, holmium, and erbium chlorides

A pharmacologic and toxicologic investigation of dysprosium, holmium, and erbium chlorides showed that these chemicals had the same delayed acute toxicity and symptoms as the other members of the rate earch group. No changes in growth or hematologic values, or evidence of histopathologic damage was observed after feeding the chemicals at three dosages for 12 weeks. On all systems studied, the three chemicals exhibited a depressant effect and produced death by respiratory paralysis coupled with cardiovascular collapse. Ocular application resulted in a transient conjunctivitis and ulceration. There were no effects on unabraded skin, but abraded skin showed extensive scar formation with epilation. The three chemicals produced nodules with foreign body giant cells and crystal formation when administered intradermally.

SKIN REACTION TO INTRADERMAL INJECTION OF RARE EARTHS.

THE availability of highly purified rare earths, elements 21 and 58–71, has stimulated interest in their chemical and physical properties1. Haley et al.2–6 have examined their biological effects and reported that although they can produce non-specific liver damage they exert their greatest toxicity on the ocular and dermal tissues. However, even this damage can be repaired with time and results in no permanent injury. Recently, it was observed that the intradermal injection in guinea pigs of 0.05 ml. aqueous solutions of 1 × 104−1 × 106 concentrations of praseodymium, neodymium, europium, dysprosium, hol-mium, erbium or lutetium chlorides resulted in the formation of 2-mm diameter nodules containing crystalline deposits (Fig. 1). Observation for periods of 45 days showed no decrease in nodule size or any resorption of the crystalline deposits.

The thermal decomposition of the heavier rare earth metal chloride hydrates

The thermal decomposition of the 6-hydrates of europium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium chlorides was studied on the thermmbalance. The 6-hydrates began to lose water of hydration in the 65° to 95°C temperature range. Because of the decreasing basicity of the metal ions, horizontal weight levels corresponding to the anhydrous metal chlorides were not found. Instead, the decomposition curves in the 200° to 265°C temperature range corresponded to the composition, MOCl·2MCl 3. On increasing the temperature, these compounds decomposed to form the metal oxychlorides in the 360° to 425°C temperature range.