Molecular formula
C16H23NO5
484 compounds have this formula on CompoundList.
- Molar mass
- 309.36g/mol
- Monoisotopic mass
- 319.2204Da
- Atoms
- 45
- Elements
- 4
- Rings plus double bonds
- 6
The formula C16H23NO5 describes a molecule made of 16 carbon atoms, 23 hydrogen atoms, 1 nitrogen atom and 5 oxygen 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 × 1662.12%12.011 × 16 = 192.176 g/mol
- H Hydrogen × 237.49%1.008 × 23 = 23.184 g/mol
- N Nitrogen × 14.53%14.007 × 1 = 14.007 g/mol
- O Oxygen × 525.86%15.999 × 5 = 79.995 g/mol
Look up another formula
Compounds with the formula C16H23NO5
Isomers we list, best known first. Open one to see its structure, properties, safety data and suppliers.
Showing 301 to 400 of 484 compounds
![3-{[(Benzyloxy)carbonyl]amino}-4-methoxy-5-methylhexanoic acid chemical structure, C16H23NO5, CAS 1849602-64-7](/s/JDTZPXXGLVLGSV-UHFFFAOYSA-N.svg)
3-{[(Benzyloxy)carbonyl]amino}-4-methoxy-5-methylhexanoic acid
CAS 1849602-64-7C16H23NO5
![2-{[(Benzyloxy)carbonyl]amino}-4-ethoxy-4-methylpentanoic acid chemical structure, C16H23NO5, CAS 2138752-68-6](/s/RQUUAYOXQHYSCX-UHFFFAOYSA-N.svg)
2-{[(Benzyloxy)carbonyl]amino}-4-ethoxy-4-methylpentanoic acid
CAS 2138752-68-6C16H23NO5
![2-{[(Benzyloxy)carbonyl]amino}-4-methoxy-5-methylhexanoic acid chemical structure, C16H23NO5, CAS 1869401-92-2](/s/JAIZXFDJMPAJAB-UHFFFAOYSA-N.svg)
2-{[(Benzyloxy)carbonyl]amino}-4-methoxy-5-methylhexanoic acid
CAS 1869401-92-2C16H23NO5
![2-{[(Benzyloxy)carbonyl]amino}-4-hydroxy-4,5-dimethylhexanoic acid chemical structure, C16H23NO5, CAS 2138998-27-1](/s/ZPVHEXSFKOIADH-UHFFFAOYSA-N.svg)
2-{[(Benzyloxy)carbonyl]amino}-4-hydroxy-4,5-dimethylhexanoic acid
CAS 2138998-27-1C16H23NO5
![tert-Butyl N-{2-hydroxy-5-[(1-hydroxycyclopropyl)methyl]-3-methoxyphenyl}carbamate chemical structure, C16H23NO5, CAS 2228566-62-7](/s/XPHSFONGASJCHN-UHFFFAOYSA-N.svg)
tert-Butyl N-{2-hydroxy-5-[(1-hydroxycyclopropyl)methyl]-3-methoxyphenyl}carbamate
CAS 2228566-62-7C16H23NO5
![tert-Butyl N-[2-(1-hydroxyprop-2-en-1-yl)-4,5-dimethoxyphenyl]carbamate chemical structure, C16H23NO5, CAS 2229212-03-5](/s/BUFYKFDUVFHNCI-UHFFFAOYSA-N.svg)
tert-Butyl N-[2-(1-hydroxyprop-2-en-1-yl)-4,5-dimethoxyphenyl]carbamate
CAS 2229212-03-5C16H23NO5
![tert-Butyl N-[2-(1-hydroxycyclopropyl)-4,5-dimethoxyphenyl]carbamate chemical structure, C16H23NO5, CAS 2228682-21-9](/s/IXSRTDUXFSOQNB-UHFFFAOYSA-N.svg)
tert-Butyl N-[2-(1-hydroxycyclopropyl)-4,5-dimethoxyphenyl]carbamate
CAS 2228682-21-9C16H23NO5
![tert-Butyl N-[4,5-dimethoxy-2-(1-oxopropan-2-yl)phenyl]carbamate chemical structure, C16H23NO5, CAS 2228686-78-8](/s/BUBNUNADYFQTRJ-UHFFFAOYSA-N.svg)
tert-Butyl N-[4,5-dimethoxy-2-(1-oxopropan-2-yl)phenyl]carbamate
CAS 2228686-78-8C16H23NO5
![tert-Butyl N-[1-(3-ethoxy-4-hydroxyphenyl)-2-oxoethyl]-N-methylcarbamate chemical structure, C16H23NO5, CAS 2228814-80-8](/s/UPEWLGXAUOPRNQ-UHFFFAOYSA-N.svg)
tert-Butyl N-[1-(3-ethoxy-4-hydroxyphenyl)-2-oxoethyl]-N-methylcarbamate
CAS 2228814-80-8C16H23NO5
![4-(5-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-2-methylbutanoic acid chemical structure, C16H23NO5, CAS 2228945-15-9](/s/SDWUYLGVUPTWFQ-UHFFFAOYSA-N.svg)
4-(5-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-2-methylbutanoic acid
CAS 2228945-15-9C16H23NO5
![2-(2-{[(tert-Butoxy)carbonyl]amino}-4-methoxyphenyl)butanoic acid chemical structure, C16H23NO5, CAS 2229333-91-7](/s/JHLXOXWSYDVMOM-UHFFFAOYSA-N.svg)
2-(2-{[(tert-Butoxy)carbonyl]amino}-4-methoxyphenyl)butanoic acid
CAS 2229333-91-7C16H23NO5
![2-(2-{[(tert-Butoxy)carbonyl]amino}-4-methoxyphenyl)-2-methylpropanoic acid chemical structure, C16H23NO5, CAS 2229371-11-1](/s/JESARWAPUZEKQJ-UHFFFAOYSA-N.svg)
2-(2-{[(tert-Butoxy)carbonyl]amino}-4-methoxyphenyl)-2-methylpropanoic acid
CAS 2229371-11-1C16H23NO5
![4-(2-{[(tert-Butoxy)carbonyl]amino}-5-hydroxyphenyl)-2-methylbutanoic acid chemical structure, C16H23NO5, CAS 2229145-52-0](/s/WTYHTILZKHPEGH-UHFFFAOYSA-N.svg)
4-(2-{[(tert-Butoxy)carbonyl]amino}-5-hydroxyphenyl)-2-methylbutanoic acid
CAS 2229145-52-0C16H23NO5
![Methyl (3R)-3-(4-{[(tert-butoxy)carbonyl]amino}-3-methylphenyl)-3-hydroxypropanoate chemical structure, C16H23NO5, CAS 2227832-69-9](/s/LWOYDPKPTAPVDR-CYBMUJFWSA-N.svg)
Methyl (3R)-3-(4-{[(tert-butoxy)carbonyl]amino}-3-methylphenyl)-3-hydroxypropanoate
CAS 2227832-69-9C16H23NO5
![tert-Butyl N-{2,3-dimethoxy-5-[(oxiran-2-yl)methyl]phenyl}carbamate chemical structure, C16H23NO5, CAS 2229376-05-8](/s/WXBQBKCBRZUUHA-UHFFFAOYSA-N.svg)
tert-Butyl N-{2,3-dimethoxy-5-[(oxiran-2-yl)methyl]phenyl}carbamate
CAS 2229376-05-8C16H23NO5
![3-(4-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)butanoic acid chemical structure, C16H23NO5, CAS 2228173-27-9](/s/WCAXNUGBKOSIGH-UHFFFAOYSA-N.svg)
3-(4-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)butanoic acid
CAS 2228173-27-9C16H23NO5
![3-(4-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)-2-methylpropanoic acid chemical structure, C16H23NO5, CAS 2228349-26-4](/s/YYJNOWGIMRRDNP-UHFFFAOYSA-N.svg)
3-(4-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)-2-methylpropanoic acid
CAS 2228349-26-4C16H23NO5
![2-(4-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)-2-methylpropanoic acid chemical structure, C16H23NO5, CAS 2228514-35-8](/s/UZGGVQPRVBKBMU-UHFFFAOYSA-N.svg)
2-(4-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)-2-methylpropanoic acid
CAS 2228514-35-8C16H23NO5
![tert-Butyl N-[1-(2,5-dimethoxyphenyl)-2-oxoethyl]-N-methylcarbamate chemical structure, C16H23NO5, CAS 2228816-91-7](/s/UHQSAKOOFYCVHH-UHFFFAOYSA-N.svg)
tert-Butyl N-[1-(2,5-dimethoxyphenyl)-2-oxoethyl]-N-methylcarbamate
CAS 2228816-91-7C16H23NO5
![3-(3-{[(tert-Butoxy)carbonyl]amino}phenyl)-2-hydroxy-3-methylbutanoic acid chemical structure, C16H23NO5, CAS 2228289-75-4](/s/SLXQYJMADTXVKI-UHFFFAOYSA-N.svg)
3-(3-{[(tert-Butoxy)carbonyl]amino}phenyl)-2-hydroxy-3-methylbutanoic acid
CAS 2228289-75-4C16H23NO5
![tert-Butyl N-[1-(3,4-dimethoxyphenyl)-2-oxoethyl]-N-methylcarbamate chemical structure, C16H23NO5, CAS 2228311-06-4](/s/KFWHFRIYSLRBIT-UHFFFAOYSA-N.svg)
tert-Butyl N-[1-(3,4-dimethoxyphenyl)-2-oxoethyl]-N-methylcarbamate
CAS 2228311-06-4C16H23NO5
![tert-Butyl N-{4,5-dimethoxy-2-[(oxiran-2-yl)methyl]phenyl}carbamate chemical structure, C16H23NO5, CAS 2229142-27-0](/s/OMFLUYJEEUTFOU-UHFFFAOYSA-N.svg)
tert-Butyl N-{4,5-dimethoxy-2-[(oxiran-2-yl)methyl]phenyl}carbamate
CAS 2229142-27-0C16H23NO5
![4-(4-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-2-methylbutanoic acid chemical structure, C16H23NO5, CAS 2229368-30-1](/s/SCTRAATXAIMSRB-UHFFFAOYSA-N.svg)
4-(4-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-2-methylbutanoic acid
CAS 2229368-30-1C16H23NO5
![tert-Butyl N-[2-hydroxy-3-methoxy-5-(3-oxobutyl)phenyl]carbamate chemical structure, C16H23NO5, CAS 2229473-79-2](/s/SBROKBQYBWTRTI-UHFFFAOYSA-N.svg)
tert-Butyl N-[2-hydroxy-3-methoxy-5-(3-oxobutyl)phenyl]carbamate
CAS 2229473-79-2C16H23NO5
- 3-(4-{[(tert-Butoxy)carbonyl]amino}-3-hydroxyphenyl)-2,2-dimethylpropanoic acid2229230-10-6C16H23NO5
- tert-Butyl N-{2-hydroxy-5-[1-(hydroxymethyl)cyclopropyl]-3-methoxyphenyl}carbamate2229381-92-2C16H23NO5
- 3-(5-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-3-methylbutanoic acid2229384-14-7C16H23NO5
- 3-(2-{[(tert-Butoxy)carbonyl]amino}-5-hydroxyphenyl)-2,2-dimethylpropanoic acid2228352-76-7C16H23NO5
- tert-Butyl N-[4,5-dimethoxy-2-(2-methyloxiran-2-yl)phenyl]carbamate2229611-26-9C16H23NO5
- 3-(2-{[(tert-Butoxy)carbonyl]amino}-4-methoxyphenyl)-2-methylpropanoic acid2229403-03-4C16H23NO5
- 4-{[(tert-Butoxy)carbonyl]amino}-2-hydroxy-2-methyl-4-phenylbutanoic acid2229513-87-3C16H23NO5
- tert-Butyl N-[1-(3,5-dimethoxy-4-methylphenyl)-2-oxoethyl]carbamate2229407-79-6C16H23NO5
- tert-Butyl N-[1-(2,3-dimethoxyphenyl)-2-oxoethyl]-N-methylcarbamate2228254-12-2C16H23NO5
- tert-Butyl N-[2,3-dimethoxy-5-(2-oxopropyl)phenyl]carbamate2229511-95-7C16H23NO5
- Methyl 3-(4-{[(tert-butoxy)carbonyl]amino}-3-methylphenyl)-2-hydroxypropanoate2228740-35-8C16H23NO5
- Methyl (3R)-3-(3-{[(tert-butoxy)carbonyl]amino}-4-methylphenyl)-3-hydroxypropanoate2227905-17-9C16H23NO5
- 2-(4-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-3-methylbutanoic acid2229347-66-2C16H23NO5
- tert-Butyl N-[2-(3-ethoxy-2-hydroxyphenyl)-1-oxopropan-2-yl]carbamate2229121-03-1C16H23NO5
- tert-Butyl N-[2-(2,4-dimethoxyphenyl)-1-oxopropan-2-yl]carbamate2228966-32-1C16H23NO5
- 2-(2-{[(tert-Butoxy)carbonyl]amino}-5-methoxyphenyl)-2-methylpropanoic acid2228287-38-3C16H23NO5
- tert-Butyl N-[2-(4-hydroxy-3-methoxyphenyl)-1-oxopropan-2-yl]-N-methylcarbamate2229346-28-3C16H23NO5
- 4-(4-{[(tert-Butoxy)carbonyl]amino}-3-hydroxyphenyl)-2-methylbutanoic acid2228275-80-5C16H23NO5
- 3-(5-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)butanoic acid2228975-74-2C16H23NO5
- tert-Butyl N-[2-hydroxy-3-methoxy-5-(2-methyl-1-oxopropan-2-yl)phenyl]carbamate2228657-15-4C16H23NO5
- 3-(4-{[(tert-Butoxy)carbonyl]amino}-3-hydroxyphenyl)-3-methylbutanoic acid2229252-20-2C16H23NO5
- tert-Butyl N-[2-(2,6-dimethoxyphenyl)-1-oxopropan-2-yl]carbamate2228712-05-6C16H23NO5
- tert-Butyl N-[1-(3-ethoxy-2-hydroxyphenyl)-2-oxoethyl]-N-methylcarbamate2228610-66-8C16H23NO5
- 3-(3-{[(tert-Butoxy)carbonyl]amino}-4-methylphenyl)-2-methoxypropanoic acid2228982-96-3C16H23NO5
- Methyl 3-(2-{[(tert-butoxy)carbonyl]amino}-1-hydroxypropan-2-yl)benzoate2408958-88-1C16H23NO5
- 3-(2-{[(tert-Butoxy)carbonyl]amino}-5-methoxyphenyl)-2-methylpropanoic acid2228980-49-0C16H23NO5
- 2-(2-{[(tert-Butoxy)carbonyl]amino}-5-methoxyphenyl)butanoic acid2228533-73-9C16H23NO5
- 3-(4-{[(tert-Butoxy)carbonyl]amino}-3-methylphenyl)-2-hydroxy-2-methylpropanoic acid2228419-92-7C16H23NO5
- tert-Butyl N-[2-(3-hydroxyprop-1-en-1-yl)-4,5-dimethoxyphenyl]carbamate2229646-46-0C16H23NO5
- 3-(4-{[(tert-Butoxy)carbonyl]amino}-3-methylphenyl)-2-methoxypropanoic acid2229366-81-6C16H23NO5
- tert-Butyl N-[5-(3-hydroxyprop-1-en-1-yl)-2,3-dimethoxyphenyl]carbamate2229682-64-6C16H23NO5
- Methyl (3S)-3-(4-{[(tert-butoxy)carbonyl]amino}-3-methylphenyl)-3-hydroxypropanoate2227674-13-5C16H23NO5
- tert-Butyl N-[2-(4-hydroxy-2-methoxyphenyl)-1-oxopropan-2-yl]-N-methylcarbamate2229372-71-6C16H23NO5
- tert-Butyl N-[2-(2-hydroxy-3-methoxyphenyl)-1-oxopropan-2-yl]-N-methylcarbamate2228624-31-3C16H23NO5
- tert-Butyl N-[5-(1-hydroxycyclopropyl)-2,3-dimethoxyphenyl]carbamate2229121-32-6C16H23NO5
- 3-(5-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-2,2-dimethylpropanoic acid2229548-00-7C16H23NO5
- tert-Butyl N-[1-(2,6-dimethoxy-4-methylphenyl)-2-oxoethyl]carbamate2228513-11-7C16H23NO5
- tert-Butyl N-[2,3-dimethoxy-5-(2-methyloxiran-2-yl)phenyl]carbamate2228565-97-5C16H23NO5
- Methyl 3-(4-{[(tert-butoxy)carbonyl]amino}-3-methylphenyl)-3-hydroxypropanoate2229561-81-1C16H23NO5
- 1-[2-(tert-Butoxy)-2-oxoethyl]-5-(2-methylpropyl)-2-oxo-1,2-dihydropyridine-3-carboxylic acid2138509-74-5C16H23NO5
- 2-(5-{[(tert-Butoxy)carbonyl]amino}-2-hydroxyphenyl)-3-methylbutanoic acid2228240-39-7C16H23NO5
- 3-(5-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)-2-methylpropanoic acid2228258-81-7C16H23NO5
- 2-(2-{[(tert-Butoxy)carbonyl]amino}-5-hydroxyphenyl)-3-methylbutanoic acid2228810-19-1C16H23NO5
- 3-(2-{[(tert-Butoxy)carbonyl]amino}-4-methoxyphenyl)butanoic acid2228713-82-2C16H23NO5
- 3-(2-{[(tert-Butoxy)carbonyl]amino}phenyl)-2-hydroxy-3-methylbutanoic acid2228727-48-6C16H23NO5
- tert-Butyl N-[2-(2,3-dimethoxyphenyl)-1-oxopropan-2-yl]carbamate2229090-64-4C16H23NO5
- tert-Butyl N-[5-(1-hydroxyprop-2-en-1-yl)-2,3-dimethoxyphenyl]carbamate2228175-49-1C16H23NO5
- tert-Butyl 4-hydroxy-5,8-dimethoxy-1,2,3,4-tetrahydroisoquinoline-2-carboxylate2413896-82-7C16H23NO5
- Ethyl 2-{[(tert-butoxy)carbonyl][(2-hydroxyphenyl)methyl]amino}acetate2413875-41-7C16H23NO5
- Methyl 2-{[(tert-butoxy)carbonyl]amino}-2-(4-hydroxy-3,5-dimethylphenyl)acetate2413868-29-6C16H23NO5
- 2-{[3-(2-Methoxy-2-oxoethyl)-2,4,6-trimethyl-5-(methylamino)phenyl]methoxy}acetic acid2418706-59-7C16H23NO5
- 2-(3-Amino-5-{[2-(tert-butoxy)-2-oxoethoxy]methyl}-2-methylphenyl)acetic acid2418676-43-2C16H23NO5
- 2-(5-Amino-3-{[2-(tert-butoxy)-2-oxoethoxy]methyl}-2-methylphenyl)acetic acid2418672-95-2C16H23NO5
- 2-(3-Amino-5-{[2-(tert-butoxy)-2-oxoethoxy]methyl}-4-methylphenyl)acetic acid2418678-52-9C16H23NO5
- 3-{[2-(tert-Butoxy)-2-oxoethoxy]methyl}-2-methyl-5-(methylamino)benzoic acid2418651-07-5C16H23NO5
- 2-(3-{[2-(tert-Butoxy)-2-oxoethoxy]methyl}-5-(methylamino)phenyl)acetic acid2418715-53-2C16H23NO5
- tert-Butyl N-[2-(3-ethoxy-4-hydroxyphenyl)-1-oxopropan-2-yl]carbamate2229333-09-7C16H23NO5
- tert-Butyl N-[1-(2,6-dimethoxyphenyl)-2-oxoethyl]-N-methylcarbamate2229010-18-6C16H23NO5
- tert-Butyl N-[2,3-dimethoxy-5-(1-oxopropan-2-yl)phenyl]carbamate2228683-36-9C16H23NO5
- tert-Butyl N-[2-(3-hydroxy-4-methoxyphenyl)-1-oxopropan-2-yl]-N-methylcarbamate2229073-73-6C16H23NO5
- tert-Butyl N-[2-(3,5-dimethoxyphenyl)-1-oxopropan-2-yl]carbamate2228986-26-1C16H23NO5
- tert-Butyl N-[(1S)-1-(2,6-dimethoxyphenyl)-3-oxopropyl]carbamate2137145-97-0C16H23NO5
- tert-Butyl N-[2-(2,5-dimethoxyphenyl)-1-oxopropan-2-yl]carbamate2228258-52-2C16H23NO5
- tert-Butyl N-[2-(2-hydroxy-5-methoxyphenyl)-1-oxopropan-2-yl]-N-methylcarbamate2228959-13-3C16H23NO5
- tert-Butyl N-[1-(3,5-dimethoxyphenyl)-2-oxoethyl]-N-methylcarbamate2228286-32-4C16H23NO5
- Methyl 3-(3-{[(tert-butoxy)carbonyl]amino}-4-methylphenyl)-3-hydroxypropanoate2229072-71-1C16H23NO5
- (3S)-3-{[(tert-Butoxy)carbonyl]amino}-3-(2-methoxy-5-methylphenyl)propanoic acid1366394-54-8C16H23NO5
- (3S)-3-{[(tert-Butoxy)carbonyl]amino}-3-(4-methoxy-2-methylphenyl)propanoic acid1366315-77-6C16H23NO5
- (3R)-3-{[(tert-Butoxy)carbonyl]amino}-3-(4-methoxy-2-methylphenyl)propanoic acid1366379-10-3C16H23NO5
- 2-{[(Benzyloxy)carbonyl]amino}-5-(propan-2-yloxy)pentanoic acid2139045-12-6C16H23NO5
- 2-(4-{[(tert-Butoxy)carbonyl]amino}-3-methoxyphenyl)butanoic acid2228862-19-7C16H23NO5
- 4-(3-{[(tert-Butoxy)carbonyl]amino}-4-hydroxyphenyl)-2-methylbutanoic acid2228805-33-0C16H23NO5
- 3-(3-{[(tert-Butoxy)carbonyl]amino}-4-methylphenyl)-2-hydroxy-2-methylpropanoic acid2229431-02-9C16H23NO5
- 3-(2-{[(tert-Butoxy)carbonyl]amino}-5-methoxyphenyl)butanoic acid2229540-13-8C16H23NO5
- 2-(5-{[(tert-Butoxy)carbonyl]amino}-2-methoxyphenyl)butanoic acid2229264-39-3C16H23NO5
- 3-(4-{[(tert-Butoxy)carbonyl]amino}-3-methoxyphenyl)butanoic acid2229383-52-0C16H23NO5
Frequently asked questions
What is the molar mass of C16H23NO5?
The molar mass of C16H23NO5 is 309.36 g/mol, calculated from standard atomic weights for 16 carbon atoms, 23 hydrogen atoms, 1 nitrogen atom and 5 oxygen atoms. The monoisotopic mass is 319.2204 Da.
How many compounds have the formula C16H23NO5?
CompoundList lists 484 compounds with the molecular formula C16H23NO5, including 3-{[(Benzyloxy)carbonyl]amino}-4-methoxy-5-methylhexanoic acid, 2-{[(Benzyloxy)carbonyl]amino}-4-ethoxy-4-methylpentanoic acid, 2-{[(Benzyloxy)carbonyl]amino}-4-methoxy-5-methylhexanoic acid. 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 C16H23NO5?
C16H23NO5 has a degree of unsaturation of 6. 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.