in neat (no solvent) byproducts: H2; in a quartz tube heated to 450-500°C in a stream of Br2 in Ar; purity 97percent;

aluminium in solid Ln2O3, AlBr3 (Ln:Al = 1:4) and Al powder were placed into an one-end sealed quartz tube under Ar, sealed under vac., heated at 600 K for 1 h; sealed tube was placed in a tubular furnace with a reduced temp. gradient from 750 to 460 K, vapor transport reaction for 6 h, tube was quicklyremoved from the furnace, the hot end was quenched with water, AlBr3 wa s condensed;

in hydrogen bromide byproducts: H2O; aq. HBr; dissolving ytterbium oxide in concd. aq. HBr, addn. of ammonium bromide,evapn., grinding, heating to 150°C under Ar and to 450°C under vac.; G. Meyer, Inorg. Synth. 25, 146 (1989); sublimation in vac. at 950°C8;

in hydrogen bromide oxide dissoln. in dil HBr (1:3), soln. evapn. until crystn. occured; crystals sepn. from mother liquor, drying (vac. desiccator, over CaCl2, P2O5 and alkali) to const. mass;

HBr vapor, at higher temp.;

ammonium chloride in tetrahydrofuran Schlenck vessel, dry Ar atmosphere; soln. of Sn-compd. dropwise addn. tolanthanide compd. in THF (room temperature). stirring (3 h), decomposit on with NH4Cl soln., extraction by ether; ppt. filtration; elem. anal., gas-liquid chromy.;

ammonium chloride in tetrahydrofuran Schlenck vessel, dry Ar atmosphere; soln. of Sn-compd. dropwise addn. tolanthanide compd. in THF (room temperature). stirring (3 h), decomposit on with NH4Cl soln., extraction by ether; ppt. filtration; elem. anal., gas-liquid chromy.;

in tetrahydrofuran molar ratio of Yb-compound/reducing agent 1:10, room temp., atmospheric pressure N2, 24 h;