Mellitic anhydride

Mellitic anhydride

Names
IUPAC name 4,9,14-trioxatetracyclo[10.3.0.02,6.07,11]pentadeca-1,6,11-triene-3,5,8,10,13,15-hexone
Identifiers
CAS Number	4253-24-1 N
3D model (JSmol)	Interactive image
ChemSpider	223826 N
PubChem CID	255291
InChI InChI=1S/C12O9/c13-7-1-2(8(14)19-7)4-6(12(18)21-11(4)17)5-3(1)9(15)20-10(5)16 N Key: NNYHMCFMPHPHOQ-UHFFFAOYSA-N N InChI=1/C12O9/c13-7-1-2(8(14)19-7)4-6(12(18)21-11(4)17)5-3(1)9(15)20-10(5)16 Key: NNYHMCFMPHPHOQ-UHFFFAOYAV
SMILES O=C2OC(=O)c1c4c(c3c(c12)C(=O)OC3=O)C(=O)OC4=O
Properties
Chemical formula	C12O9
Molar mass	288.12 g·mol−1
Appearance	colorless solid
Melting point	161 °C; 322 °F; 434 K
Vapor pressure	0.000004 mmHg (20°C)
Hazards
US health exposure limits (NIOSH):
PEL (Permissible)	none
REL (Recommended)	TWA 0.005 ppm (0.04 mg/m3) Should be handled in the workplace as an extremely toxic substance.
IDLH (Immediate danger)	N.D.
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Mellitic anhydride, the anhydride of mellitic acid, is an organic compound with the formula C₁₂O₉.

Mellitic anhydride is an oxide of carbon (oxocarbon), like CO₂, CO, and C₃O₂. It is a white sublimable solid, apparently obtained by Liebig and Wöhler in 1830 in their study of mellite ("honey stone"); they assigned it the empiric formula C₄O_3. The substance was properly characterized in 1913 by H. Meyer and K. Steiner. It retains the aromatic character of the benzene ring.