[en] The crystalline phases of YbBr_2 were investigated by powder neutron diffraction between 1.5 K and the melting point at 955 K (682 C). The low temperature SrI_2 phase is observed up to 550 K, the α-PbO_2 phase between 260 K and 750 K, the CaCl_2 phase between 690 K and 790 K, and the rutile phase from 790 K to the melting point. All observed phase transitions are first order, except for the second order CaCl_2 to rutile transition. The transition temperatures and enthalpies were determined by differential scanning calorimetry. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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[en] Research is summarized on thermodynamic properties of borides, ThC₂, EuC₂, oxide-carbide phases, YbOC, Eu bromides, vaporization, fluorides, Y chlorides, etc. Preliminary results are given for the preparation of Gd(III) Cl-I phases and the vaporization of YbBr₂

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[en] Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2′-bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH)₂) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr₂, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr₃ content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. - Graphical abstract: Yb-based catalyst was used for the first time for AGET ATRP of AN with BPN as the initiator, bipy as the ligand, and Sn(EH)₂ as the reducing agent in the presence of air. With respect to AGET ATRP with CuBr₂ as catalyst, an obvious increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr₃ content. The block copolymer PAN-b-PMMA with molecular weight at 60000 and polydispersity at 1.36 was successfully prepared. Highlights: ► Yb-based catalyst was used for the first time for AGET ATRP of AN. ► The reaction simultaneously controls polydispersity and tacticity of PAN. ► Well-defined block copolymer PAN-b-PMMA was successfully prepared.

[en] An account is given of the synthesis of some trihalides of Yb, Sm and Er using the reaction 3HgX₂ + 2M → 2MX₃ + 3Hg, in tetrahydrofuran. Experimental details are presented, and some properties of the lanthanoid trihalide-tetrahydrofuran complexes are discussed. (U.K.)

[en] Enthalpies of solution of high-purity terbium, holmium, and ytterbium metals and of the corresponding tribromides in aqueous hydrochloric acid of various molalities lead to the following standard molar enthalpies of formation at 298.15 K: Tb³⁺(aq), -(698.3+-1.5); Ho³⁺(aq), -(707.2+-2.4); Yb³⁺(aq), -(670.5+-2.7); Yb²⁺(aq), -(530.4+-3.3); TbBr₃(cr), -(839.1+-2.4); HoBr₃(cr), -(842.1+-2.7); YbBr₃(cr), -(793.8+-2.4). A value of -(1.06+-0.05) V is deduced from the above results for the standard potential of the reaction; Yb³⁺ +1/2H₂ = Yb²⁺ + H⁺, through the use of suitable entropy values. These results are discussed and compared with previous experimental or assessed values. (author)

[en] Conditions for Yb and Sm oxidation attachment to aryldihalides containing Br or Cl and the lanthanide interacting by C-Cl bond are found. It reaches due to application of fine-disperse suspensions of ytterbium and samarium prepared by reducing the proper waterless lanthanide bromides (YbBr₃, SmBr₃) by sodium naphthalide. In this case ytterbium enters oxidation attachment easier than samarium. The mechanism of the process is discussed

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