Ytterbium chloride

Aromatic halides such as chlorobenzene and p-fluorololuene were rapidly hy-drogenolyzed in 100% conversion by NaH of nanometric size in the presence of homogeneous catalysts. One- or two-component (e.g., Ni(OAc)2/TiCl4) systems were effective. The combination of ytterbium chloride and a transition-metal chloride showed a remarkable synergistic effect [37, 38]. 

Ylidenebutenolides, 431 Ytterbium, 517 Ytterbium-Ammonia, 517 Ytterbium chloride, 211... 

Acetals Various lanthanide chlorides are efficient catalysts for acetalization of aldehydes by methanol. Lanthanum chloride and cerium chloride are satisfactory for aliphatic aldehydes, but erbium chloride and ytterbium chloride are generally superior, particularly for aromatic and bicyclic aldehydes. Addition of trimethyl orthoformate as a water scavenger allows use of the commerically available hydrated forms of the salts. Acetals can be obtained in 80-100% yield from reactions conducted for 10 minutes at 25°. 

In another series of studies of the soluble lanthanide chlorides, rats were fed gadolinium, samarium, terbium, thulium, ytterbium, praseodymium, neodymium, lutetium, europium, dysprosium, holmium, and erbium chloride in their diet at doses of 0, 5, 50, and 500 mg kg day for 12 weeks. Only ytterbium chloride caused any significant effect, with the 500 mg kg dose causing gastric hemorrhages. The other lanthanides caused no adverse effects at the maximum 500 mg kg dose. 

The asymmetric addition of trimethylsilylcyanide to aldehyde was catalyzed by a chirally modified Lewis acid. Polymer-supported chiral bis(oxazoline)s (46, 47) were prepared and used as ligands of ytterbium chloride ]30]. The polymeric hgands exhibited as high a reactivity in the asymmetric silylcyanation as did their... 

Smolyakova and Serebrennikov [78SMO/SER] measured the enthalpy change of the reaction between an aqueous solution of ytterbium chloride and Na2Se03(cr). The description of the experiments and calculations is somewhat meagre. Their data have been re-evaluated as described in Appendix A and yielded the result Af//° (Yb2(Se03)3-8H20, am, 298.15 K) = (5115 7) kJ-mol. ... 

Parafoimaldehyde (2 moles) and 2,6-di-tert-butyl-phenol and catalyst, 10% Pd-C and ytterbium chloride hydrogenated (7Kg/cmT) at ambient temp, to give 2,6-di-tert-butyl-4-methylphenol. 

Dimeric dicyclopentadienyl ytterbium chloride monomerizes at the ion source temperature of 250°C, but at 180°C removal of cyclopentadienyl ligands is found with formation of YbjCl J ions (Muller, 1969). 

Investigations by Bielang and R.D. Fischer (1978) demonstrate that the reactions of dicyclopentadienyl ytterbium chloride with lithium di(cyclohexyI)phosphide, lithium cyclohexylphosphide and lithium phenylphosphide are rather complicated. The decomposition behavior of these very sensitive substances is complex. It was possible to isolate Cp2YbP(QHji)2, but Cp2YbPHPh and Cp2YbPHQH decompose with formation of polymeric species [CpYbPPh] and [CpYbPQH,] . 

The first compounds containing bonds between dicyclopentadienyl rare earth moieties and elements of group IV have been prepared by Schumann and Cygon (1978). Dicyclopentadienyl erbium chloride and dicyclopentadienyl ytterbium chloride react with lithium triphenylgermane or triphenylstannane with formation of dicyclopentadienyl erbium triphenylgermane and -stannane and dicyclopentadienyl ytterbium triphenylstannane, the latter containing two tetrahydrofuran molecules coordinated to ytterbium ... 

YCI3, Yttrium chloride, 22 39 YN4O2C44IU, Yttrium, (2,4-pentanedion-ato)[S,10,lS,20-tetraphenylpotphyri-nato(2-)]-, 22 160 YbCls, Ytterbium chloride, 22 39 YbF4N402C55H43, Ytterbium, [5,10,15,20-te-ttakis(3-fluorophenyl)poiphyrinato-(2 — )](2,2,6,6-tetramethyl-3,S-beptane-dionato)-, 22 160... 

The dimer of bis( ) -methylcyclopentadienyl)ytterbium chloride has been investigated with the INDO method (Li et al. 1987a). The weak interaction between the Yb atoms is due to chlorine bridges and not to a Yb-Yb bond. 

---