Ytterbium dichloride

YbCI2 YTTERBIUM DICHLORIDE 1824 ZrBt2[g] ZIRCONIUM DIBROMIDE (GAS) 1857... 

Jia (1990) has described the molecular constants of RX2 (R = La-Lu X = F, Cl, Br, I) by taking into accoimt the data reported by Krasnov and Timoshinin (1969), the molecular characteristics of samarium, europium, and ytterbium dichlorides and difluorides obtained from their IR spectra (DeKock et al., 1972 Hastie et al., 1971), as well as estimates by Filippenko... 

Indeed, when Johnson (1969) published his paper, four experimental values of AfH°(RCl2, cr, 298) were known, for neodymium, samarium, europium, and ytterbium dichlorides. One decade later, Kim and Oishi (1979) could compare their estimates with the experimental values for six dichlorides, dysprosium and thulium dichlorides data having been added in the meantime. 

Such a close agreement between the calculated and experimental enthalpies of formation for samarium, europium, thulium, and ytterbium dichlorides allows us to claim that the calculation scheme used in the framework of this study leads to reliable results provided that the reference values are chosen adequately. 

Pogrebnoi, A.M., 2004. Molecular and ion associates in vapors over lanthanide chlorides and solid electrolytes. Extended Abstract of Doctoral (Chem) Dissertation, Ivanovo (in Russian). Pogrebnoi, A.M., Kudin, L.S., 2003a. Neutral and charged species in saturated vapour over samarium, europium and ytterbium dichlorides. In Proceedings of the II International Symposium on High Temperature Mass Spectrometry (Plyos, 2003), Ivanovo, pp. 110-117. 

The combination of dicyclopentadienylzirconium dichloride and silver perchlorate activates armed glycosyl sulfoxides in dichloromethane between -20 °C and room temperature, but only very simple acceptors were studied [335]. Other Lewis and Bronsted acids studied include the environmentally benign europium, lanthanum and ytterbium triflates [336], certain polyoxometallates [337], sulfated zirconia [338] and Nafion H [338]. 

Roesky introduced bis(iminophosphorano)methanides to rare earth chemistry with a comprehensive study of trivalent rare earth bis(imino-phosphorano)methanide dichlorides by the synthesis of samarium (51), dysprosium (52), erbium (53), ytterbium (54), lutetium (55), and yttrium (56) derivatives.37 Complexes 51-56 were prepared from the corresponding anhydrous rare earth trichlorides and 7 in THF and 51 and 56 were further derivatised with two equivalents of potassium diphenylamide to produce 57 and 58, respectively.37 Additionally, treatment of 51, 53, and 56 with two equivalents of sodium cyclopentadienyl resulted in the formation of the bis(cyclopentadienly) derivatives 59-61.38 In 51-61 a metal-methanide bond was observed in the solid state, and for 56 this was shown to persist in solution by 13C NMR spectroscopy (8Ch 17.6 ppm, JYc = 3.6 2/py = 89.1 Hz). However, for 61 the NMR data suggested the yttrium-carbon bond was lost in solution. DFT calculations supported the presence of an yttrium-methanide contact in 56 with a calculated shared electron number (SEN) of 0.40 for the yttrium-carbon bond in a monomeric gas phase model of 56 for comparison, the yttrium-nitrogen bond SEN was calculated to be 0.41. 

Cl2Si4Yb2C44Hj4, Ytterbium, tetrakis[Ti -l,3-bis(trimethylsilyl)cyclopentadienyl]di-p-chloro-di-, 27 171 Cl2Zn, Zinc dichloride, 28 322, 29 110 CI3AS2NRUSC36H3Q, Ruthenium(Il), tri-chloro(thionitrosyl)bis(triphenyl-arsine)-, 29 162... 

Perchloric acid Phosphomolybdic acid Phosphorus oxychloride Phosphorus pentachloride Phosphorus trichloride y-Picoline Polyphosphoric acid Potassium silicate Rhodium Selenium Selenium dioxide Silica gel Silver oxide (ous) Sodium borohydride Sodium silicate Strontium carbonate Sulfur dioxide Tantalum Tellurium Tetraisopropyl di (dioctylphosphito) titanate Titanocene dichloride Trichloromethylphosphonic acid Tristriphenylphosphine rhodium carbonyl hydride Tungsten carbide Vermiculite Ytterbium oxide Zinc chloride Zinc dust Zinc 2-ethylhexanoate Zirconium potassium hexafluoride... 

Most of the known monocyclopentadienyl compounds of trivalent lanthanoids are dichloride complexes of CpLnCl2(THF) type. Besides these compounds, the ytterbium p-diketonates, lanthanum and cerium iodides (Me5C5)Lnl2 and the lutetium triflate complex CpLu(0S02CF3)2(THF)3 have been obtained (Table 111.14)... 

A product of different type is formed when ytterbium reacts with dichloride Ph2SnCl2. In this case the process includes a deep transformation of the initial tin dichloride leading to the ionic complex with tetratin anions [(Ph3Sn)3Sn] and binuclear ytterbium cation [(DME)3Yb(n-Cl)]2 [31]. 

The reference enthalpies of formation for barimn, europium, and ytterbium plotted as a fimction of the atomic nmnber (Ba, La-Lu = 1-16) and for the dichlorides of these elements (see Table 52) were fitted to smooth curves by means of a second-order polynomial. 

We suppose that Eq. (30) can be applied to estimate the heat capacities of liquids, but for a limited number of lanthanide dichlorides only. We used this equation to estimate Cp(EuCl2, liq) and Cp(YbCl2, liq). These substances were selected because there is no excess contribution to the heat capacities of the lanthanides themselves (see Martin et al., 1978) and their dichlorides (see Table 7). The calculated Cp(EuCl2, liq) and Cp(YbCl2, liq) values were 105.8 and 106.5 J/(mol-K), respectively. These data were obtained using the heat capacities of europium and ytterbium from the database (IVTANTERMO, 2004) and the lattice heat capacity components Ciat(liq) from Qrervonnyi and Chervonnaya (2007b) as the heat capacities of europium and ytterbium trichlorides. 

Usually, trends in AatH°(298) variations depending on the atomic numbers of lanthanides are considered. This dependence, however, has the form of a broken line with maxima at lanthanum, gadolinium, and lutetium and minima at europium and ytterbium. In addition, an increase in AatH°(298) is usually observed when going from dysprosium to erbium compoimds. A smoother dependence on the atomic number of lanthanides was obtained for the enthalpies of sublimation of lanthanide trifluorides and trichlorides. We believe that the use of this feature allows Asubhf°(298) values to be predicted more accurately for separate lanthanide dichlorides. Accordingly, the reliability of all the thermodynamic data can then be estimated. 

The Heats of Reaction of the Dichlorides of Samarium and Ytterbium with Hydrochloric Acid. A Microcalorimeter, G.R. Machlan, C.T. Stubblefield and L. Eyring, J. Amer Chem. Soc., 77, 2975-2978 (1955). 

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