ytterbium(III) Chloride
Properties
| State | Solid (hygroscopic; commonly hydrated) |
| Color | white to pale yellow |
| Solubility | Very soluble in water; soluble in alcohols |
| Melting Point | 896 °C (anhydrous) |
About ytterbium(III) Chloride
Ytterbium(III) chloride is a white-to-pale-yellow hygroscopic salt — anhydrous YbCl3 has a molar mass of 279.4 g/mol, but you almost never buy it that way. The bottle on the shelf is the heptahydrate or hexahydrate, because the anhydrous form is a pain to make from solution: dehydrating the hydrate in moist air gives YbOCl (the oxychloride) instead of clean YbCl3. To get genuinely anhydrous material you either vacuum-sublime it, heat the hydrate with NH4Cl under argon, or react Yb metal with Cl2 directly. In the solid state the Yb(III) center sits in a 9-coordinate tricapped trigonal prism, the typical geometry for the larger trivalent rare-earth cations. YbCl3 is the workhorse precursor for ytterbium chemistry: doped crystals, fiber-laser preforms, Yb(II) reduction studies (YbCl2 is reachable via sodium-naphthalenide reduction in THF), and — most usefully for the synthesis community — it is the starting material for ytterbium(III) triflate, the most popular water-tolerant Lewis acid catalyst in modern green chemistry.
Where you'll encounter it
If you've ever ordered a rare-earth chloride from Strem or Sigma-Aldrich for an organometallic project, you've likely opened a brown glass bottle of YbCl3·6H2O sitting in a desiccator, and watched it start to bead with water the moment the lid came off. In a synthesis lab, the most common job for YbCl3 is feeding the next bench over: you weigh out the hydrate, dissolve it in degassed water with triflic acid, and recover Yb(OTf)3 after evaporation and drying. In a laser-materials facility, YbCl3 is the dopant source that goes into the precursor melt for Yb:YAG single-crystal growth or into the modified-chemical-vapor-deposition (MCVD) process for Yb-doped silica fiber preforms — the same fibers that end up in 10-kilowatt cutting lasers on factory floors.
Common Uses
- Precursor for synthesis of ytterbium(III) triflate Lewis-acid catalyst
- Dopant feedstock for Yb:YAG single-crystal growth and Yb:silica fiber preforms
- Starting material for organolanthanide complexes via salt metathesis
- Source of Yb(II) reagents after reduction with sodium-naphthalenide in THF
- Lanthanide reference standard in ICP-MS calibration of rare-earth analyses
Safety Information
GHS classification: Skin irritation Category 2 (H315), Eye irritation Category 2A (H319), STOT SE Category 3 respiratory tract irritation (H335). Acute oral toxicity is moderate (LD50 oral rat for related YbCl3·6H2O around 480 mg/kg). The hydrate releases small amounts of HCl on heating or contact with strong dehydrating reagents, so handle in a fume hood when sublimating or reacting with NH4Cl. There is no occupational exposure limit specific to ytterbium compounds, so the dust falls under the general nuisance-particulate limits for total and respirable fractions. Standard PPE: nitrile gloves, splash goggles, lab coat. Store sealed under desiccant.
This safety summary is for educational reference only and may not be complete. It is not a substitute for Safety Data Sheets (SDS), medical advice, or professional chemical safety guidance. Always consult appropriate SDS and qualified professionals before handling chemicals. We deliberately do not publish occupational exposure limits or other regulatory thresholds: those values are revised over time and differ between jurisdictions, so the only correct source is the current SDS and the regulations that apply where you work.