cover image

Osmium tetroxide

Chemical compound / From Wikipedia, the free encyclopedia

Dear Wikiwand AI, let's keep it short, summarize this topic like I'm... Ten years old or a College student

Osmium tetroxide (also osmium(VIII) oxide) is the chemical compound with the formula OsO4. The compound is noteworthy for its many uses, despite its toxicity and the rarity of osmium. It also has a number of unusual properties, one being that the solid is volatile. The compound is colourless, but most samples appear yellow.[5] This is most likely due to the presence of the impurity OsO2, which is yellow-brown in colour.[6] In biology, its property of binding to lipids has made it a widely-used stain in electron microscopy.

Quick facts: Names, Identifiers, Properties, Structure[3],...
Osmium tetroxide
Stick model osmium tetroxide
Ball and stick model of osmium tetroxide
Names
Preferred IUPAC name
Osmium tetraoxide
Systematic IUPAC name
Tetraoxoosmium
Other names
Osmium(VIII) oxide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.040.038
EC Number
  • 244-058-7
MeSH Osmium+tetroxide
RTECS number
  • RN1140000
UNII
UN number UN 2471
  • InChI=1S/4O.Os Y
    Key: VUVGYHUDAICLFK-UHFFFAOYSA-N Y
  • InChI=1S/4O.Os
    Key: VUVGYHUDAICLFK-UHFFFAOYSA-N
  • InChI=1/4O.Os/rO4Os/c1-5(2,3)4
    Key: VUVGYHUDAICLFK-TYHKRQCIAE
  • O=[Os](=O)(=O)=O
Properties
OsO4
Molar mass 254.23 g/mol
Appearance White volatile solid
Odor Acrid, chlorine-like
Density 4.9 g/cm3[1]
Melting point 40.25 °C (104.45 °F; 313.40 K)
Boiling point 129.7 °C (265.5 °F; 402.8 K)
5.70 g/100 mL (10 °C)
6.23 g/100 mL (25 °C)
Solubility Soluble in most organic solvents, ammonium hydroxide, phosphorus oxychloride
Solubility in CCl4 375 g/100 mL
Vapor pressure 7 mmHg (20 °C)[2]
Structure[3]
Monoclinic, mS20
C2/c
a = 9.379 Å, b = 4.515 Å, c = 8.630 Å
α = 90°, β = 116.58°, γ = 90°
326.8 Å3
4
tetrahedral
Hazards
GHS labelling:
Danger
H300, H310, H314, H330
P260, P262, P264, P270, P271, P280, P284, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P310, P320, P321, P322, P330, P361, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)
Lethal dose or concentration (LD, LC):
1316 mg/m3 (rabbit, 30 min)
423 mg/m3 (rat, 4 hr)
423 mg/m3 (mouse, 4 hr)[4]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 0.002 mg/m3[2]
REL (Recommended)
TWA 0.002 mg/m3 (0.0002 ppm) ST 0.006 mg/m3 (0.0006 ppm)[2]
IDLH (Immediate danger)
1 mg/m3[2]
Safety data sheet (SDS) ICSC 0528
Related compounds
Other cations
Ruthenium tetroxide
Related osmium oxides
Osmium(IV) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Close