C21H18
60 compounds have this formula on CompoundList.
- Molar mass
- 270.38g/mol
- Monoisotopic mass
- 270.1409Da
- Atoms
- 39
- Elements
- 2
- Rings plus double bonds
- 13
The formula C21H18 describes a molecule made of 21 carbon atoms and 18 hydrogen atoms. It is written in Hill notation: carbon first, then hydrogen, then the other elements in alphabetical order. The formula tells you which atoms are present, not how they are connected, which is why several different chemicals can share it.
Elemental composition
- C Carbon × 2193.29%12.011 × 21 = 252.231 g/mol
- H Hydrogen × 186.71%1.008 × 18 = 18.144 g/mol
Compounds with the formula C21H18
Isomers we list, best known first. Open one to see its structure, properties, safety data and suppliers.
Showing 1 to 60 of 60 compounds
![5,7,12-Trimethylbenz[a]anthracene chemical structure, C21H18, CAS 24891-39-2](/s/QCOYHXBAFQMVDF-UHFFFAOYSA-N.svg)
- 6,7,8-Trimethylbenz(a)anthracene20627-32-1C21H18
- Benz(a)anthracene, 6,7,12-trimethyl-20627-33-2C21H18
- 9-(2-Phenylethyl)-9H-fluorene10423-31-1C21H18
- 1-(Diphenylmethyl)-4-vinylbenzene47128-23-4C21H18
- 5-Propylbenzo[c]phenanthrene63020-32-6C21H18
- 6,8,12-Trimethylbenz(a)anthracene20627-34-3C21H18
- Cholanthrene, 11,12-dihydro-3-methyl-25486-92-4C21H18
- Benzo(a)pyrene, 7,8,9,10-tetrahydro-7-methyl-94849-90-8C21H18
- 2,6,10-Trimethyltriphenylene111799-94-1C21H18
- [(E)-1,3-Diphenyl-prop-2-enyl]-benzene5424-75-9C21H18
- 6,9,10-Trimethylbenzo(a)anthracene6610-40-8C21H18
- 7,8-Diphenylbicyclo[4.2.1]nona-2,4,7-triene54049-09-1C21H18
- [(Z)-1,3-Diphenylprop-1-en-2-yl]benzene24423-97-0C21H18
- 2-(Propan-2-yl)tetracene62775-16-0C21H18
- 9-(2,6-Dimethylphenyl)-9H-fluorene18153-41-8C21H18
- 9,9-Dimethyl-1-phenyl-9H-fluorene1946842-99-4C21H18
- 10-Methyl-7,8,9,10-tetrahydrobenzo(a)pyrene94849-98-6C21H18
- (1R,2R)-1,2-Diphenyl-2,3-dihydro-1H-indene22256-19-5C21H18
- 6-Propylchrysene6910-41-4C21H18
- 1-Ethyl-2-methylchrysene74869-43-5C21H18
- 6-Ethyl-5-methylchrysene74869-23-1C21H18
- 7H-Dibenzo-8,9,10,11-tetrahydro-78631-72-8C21H18
- 5,6,7-Trimethylbenzo(a)anthracene60826-78-0C21H18
- 1,1'-[1-(4-Methylphenyl)ethene-1,2-diyl]dibenzene70603-14-4C21H18
- 9-(4-Methylbenzyl)-9H-fluorene745809-62-5C21H18
- 9,9-Dimethyl-3-phenyl-9H-fluorene2515505-14-1C21H18
- 1,2,3-Trimethylchrysene60826-77-9C21H18
- 4-Ethyl-3-methyltetraphene61982-79-4C21H18
- 9-Benzyl-9-methyl-9H-fluorene61076-90-2C21H18
- 4,7-Diphenyl-3a,7a-dihydro-1H-indene88044-02-4C21H18
- 9-Methyl-9-(2-methylphenyl)-9H-fluorene88172-47-8C21H18
- 9-Benzyl-1-methyl-9H-fluorene87823-43-6C21H18
- 1-(2-Phenylprop-2-EN-1-yl)-1,2-dihydroacenaphthylene61025-16-9C21H18
- 2,4,5-Trimethylchrysene74869-25-3C21H18
- 2'-Methyl-3,4-dihydro-1,1'-binaphthalene87829-16-1C21H18
- (1S,3S)-1,3-Diphenyl-2,3-dihydro-1H-indene113755-11-6C21H18
Frequently asked questions
What is the molar mass of C21H18?
The molar mass of C21H18 is 270.38 g/mol, calculated from standard atomic weights for 21 carbon atoms and 18 hydrogen atoms. The monoisotopic mass is 270.1409 Da.
How many compounds have the formula C21H18?
CompoundList lists 60 compounds with the molecular formula C21H18, including 7,8,12-Trimethylbenz(a)anthracene, 1-(2,2-Diphenylvinyl)-4-methylbenzene, 8,9,11-Trimethylbenz(A)anthracene. Compounds that share a formula are isomers. They contain the same atoms arranged differently, so their properties, uses and prices can be very different.
What is the degree of unsaturation of C21H18?
C21H18 has a degree of unsaturation of 13. That is the total number of rings and pi bonds (a double bond counts as one, a triple bond as two) in any structure with this formula.