Molecular formula
C19H23N5O2
216 compounds have this formula on CompoundList.
- Molar mass
- 353.43g/mol
- Monoisotopic mass
- 353.1852Da
- Atoms
- 49
- Elements
- 4
- Rings plus double bonds
- 11
The formula C19H23N5O2 describes a molecule made of 19 carbon atoms, 23 hydrogen atoms, 5 nitrogen atoms and 2 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 × 1964.57%12.011 × 19 = 228.209 g/mol
- H Hydrogen × 236.56%1.008 × 23 = 23.184 g/mol
- N Nitrogen × 519.82%14.007 × 5 = 70.035 g/mol
- O Oxygen × 29.05%15.999 × 2 = 31.998 g/mol
Look up another formula
Compounds with the formula C19H23N5O2
Isomers we list, best known first. Open one to see its structure, properties, safety data and suppliers.
Showing 1 to 100 of 216 compounds
Epiroprim
CAS 73090-70-7C19H23N5O2
7-Benzyl-3-methyl-8-(4-methylpiperidin-1-yl)-1H-purine-2,6(3H,7H)-dione
CAS 575463-32-0C19H23N5O2
8-(Cyclopentylamino)-3-methyl-7-(3-methylbenzyl)-1H-purine-2,6(3H,7H)-dione
CAS 797028-13-8C19H23N5O2
1-sec-Butyl-N-ethyl-2-imino-10-methyl-5-oxo-1,5-dihydro-2H-dipyrido(1,2-A:2,3-D)pyrimidine-3-carboxamide
CAS 510733-37-6C19H23N5O2
7-Benzyl-3-methyl-8-(3-methylpiperidin-1-yl)-1H-purine-2,6(3H,7H)-dione
CAS 579442-65-2C19H23N5O2
![3-Ethyl-1-methyl-9-phenethyl-6,7,8,9-tetrahydropyrimido[2,1-f]purine-2,4(1H,3H)-dione chemical structure, C19H23N5O2, CAS 849920-54-3](/s/DOCLWCRMXUSGTF-UHFFFAOYSA-N.svg)
3-Ethyl-1-methyl-9-phenethyl-6,7,8,9-tetrahydropyrimido[2,1-f]purine-2,4(1H,3H)-dione
CAS 849920-54-3C19H23N5O2
8-Azepan-1-yl-7-benzyl-3-methyl-3,7-dihydro-purine-2,6-dione
CAS 299419-32-2C19H23N5O2
![2-(1-tert-Butyl-4-oxo-1,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-5-yl)-N-(2-phenylethyl)acetamide chemical structure, C19H23N5O2, CAS 863448-11-7](/s/OHXGHIMHKYBRAN-UHFFFAOYSA-N.svg)
2-(1-tert-Butyl-4-oxo-1,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-5-yl)-N-(2-phenylethyl)acetamide
CAS 863448-11-7C19H23N5O2
8-Cyclopentylamino-3-methyl-7-(2-methyl-benzyl)-3,7-dihydro-purine-2,6-dione
CAS 587008-44-4C19H23N5O2
![9-Benzyl-1-methyl-3-propyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione chemical structure, C19H23N5O2, CAS 850751-28-9](/s/RODYALQYNGDRGQ-UHFFFAOYSA-N.svg)
9-Benzyl-1-methyl-3-propyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione
CAS 850751-28-9C19H23N5O2
(4-(6-Morpholinopyridazin-3-yl)piperazin-1-yl)(phenyl)methanone
CAS 898460-04-3C19H23N5O2
![2-(Dimethylamino)-4-[4-(2,6-dimethylphenyl)piperazino]-6-oxo-6H-1,3-oxazine-5-carbonitrile chemical structure, C19H23N5O2, CAS 303997-32-2](/s/MAJXJDMOJNJLJM-UHFFFAOYSA-N.svg)
2-(Dimethylamino)-4-[4-(2,6-dimethylphenyl)piperazino]-6-oxo-6H-1,3-oxazine-5-carbonitrile
CAS 303997-32-2C19H23N5O2
![1,3,7-Trimethyl-9-(2-phenylethyl)-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione chemical structure, C19H23N5O2, CAS 877616-21-2](/s/HUFXOSPZPQQMPD-UHFFFAOYSA-N.svg)
1,3,7-Trimethyl-9-(2-phenylethyl)-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione
CAS 877616-21-2C19H23N5O2
5-Amino-1-tert-butyl-3-(7-ethoxyquinolin-3-yl)-1H-pyrazole-4-carboxamide
CAS 1493524-11-0C19H23N5O2
![1-Ethyl-3-{[2-(1-methylpropylidene)hydrazino]methylene}-6-(6-oxo-1,4,5,6-tetrahydro-3-pyridazinyl)-1,3-dihydro-2H-indol-2-one chemical structure, C19H23N5O2, CAS 2649561-54-4](/s/XYFHRLDFNOKNQV-PXQYURKDSA-N.svg)
1-Ethyl-3-{[2-(1-methylpropylidene)hydrazino]methylene}-6-(6-oxo-1,4,5,6-tetrahydro-3-pyridazinyl)-1,3-dihydro-2H-indol-2-one
CAS 2649561-54-4C19H23N5O2
Jnj-42396302
CAS 1298030-18-8C19H23N5O2
3-Methyl-7-phenethyl-8-(piperidin-1-yl)-1H-purine-2,6(3H,7H)-dione
CAS 313230-33-0C19H23N5O2
![4-[3-[6-(2-Methoxyethyl)pyridin-3-yl]-2-methylimidazo[1,2-a]pyrazin-8-yl]morpholine chemical structure, C19H23N5O2, CAS 1334165-90-0](/s/XVWPXHVWMMHZOG-UHFFFAOYSA-N.svg)
4-[3-[6-(2-Methoxyethyl)pyridin-3-yl]-2-methylimidazo[1,2-a]pyrazin-8-yl]morpholine
CAS 1334165-90-0C19H23N5O2
![5-Butyl-2-[(4,6,7-trimethyl-2-quinazolinyl)amino]-4,6-pyrimidinediol chemical structure, C19H23N5O2, CAS 364737-85-9](/s/IBHTZXRKJQUWNJ-UHFFFAOYSA-N.svg)
5-Butyl-2-[(4,6,7-trimethyl-2-quinazolinyl)amino]-4,6-pyrimidinediol
CAS 364737-85-9C19H23N5O2
![N-(2-(4-(2-Oxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)piperidin-1-yl)ethyl)-1H-pyrrole-2-carboxamide chemical structure, C19H23N5O2, CAS 1130067-26-3](/s/XDFGIRYIOADGQC-UHFFFAOYSA-N.svg)
N-(2-(4-(2-Oxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)piperidin-1-yl)ethyl)-1H-pyrrole-2-carboxamide
CAS 1130067-26-3C19H23N5O2
![3-{1-tert-Butyl-4-oxo-1H,4H,5H-pyrazolo[3,4-d]pyrimidin-5-yl}-N-(4-methylphenyl)propanamide chemical structure, C19H23N5O2, CAS 952970-55-7](/s/SAZTVFIPOKWKBF-UHFFFAOYSA-N.svg)
3-{1-tert-Butyl-4-oxo-1H,4H,5H-pyrazolo[3,4-d]pyrimidin-5-yl}-N-(4-methylphenyl)propanamide
CAS 952970-55-7C19H23N5O2
![N-Cyclopropyl-3-[4-(2-methylpropyl)-5-oxo-4H,5H-[1,2,4]triazolo[4,3-a]quinazolin-1-yl]propanamide chemical structure, C19H23N5O2, CAS 902929-47-9](/s/NGEMSWCMXIAVGB-UHFFFAOYSA-N.svg)
N-Cyclopropyl-3-[4-(2-methylpropyl)-5-oxo-4H,5H-[1,2,4]triazolo[4,3-a]quinazolin-1-yl]propanamide
CAS 902929-47-9C19H23N5O2
![N-(2-(5-(3-Methylbenzyl)-4-oxo-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-1-yl)ethyl)butyramide chemical structure, C19H23N5O2, CAS 922117-91-7](/s/LKWHXNGPQRQPCG-UHFFFAOYSA-N.svg)
N-(2-(5-(3-Methylbenzyl)-4-oxo-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-1-yl)ethyl)butyramide
CAS 922117-91-7C19H23N5O2
3-Methyl-7-(3-phenylpropyl)-8-(pyrrolidin-1-yl)-1H-purine-2,6(3H,7H)-dione
CAS 377054-13-2C19H23N5O2
- 6-[3-(1-Cyclohexyl-1H-tetrazol-5-yl) propoxy]-2(1H)-quinolinone73963-46-9C19H23N5O2
- 1,3-Dimethyl-7-(2-phenylethyl)-8-(pyrrolidin-1-yl)-3,7-dihydro-1H-purine-2,6-dione335403-53-7C19H23N5O2
- 7-Benzyl-3-methyl-8-(2-methylpiperidin-1-yl)-1H-purine-2,6(3H,7H)-dione575470-10-9C19H23N5O2
- 1,3-Dimethyl-7-(3-methylbenzyl)-8-(pyrrolidin-1-yl)-1H-purine-2,6(3H,7H)-dione361174-72-3C19H23N5O2
- 8-[Benzyl(methyl)amino]-1,3-dimethyl-7-(2-methylprop-2-enyl)purine-2,6-dione377054-37-0C19H23N5O2
- 3-Ethyl-1,7-dimethyl-9-(3-methylphenyl)-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione848727-23-1C19H23N5O2
- 1-Methyl-9-(4-methylphenyl)-3-propyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione846061-74-3C19H23N5O2
- 7-Benzyl-1,3-dimethyl-8-(piperidin-1-yl)-3,7-dihydro-1H-purine-2,6-dione359697-72-6C19H23N5O2
- 9-(4-Butylphenyl)-1-methyl-1,3,5-trihydro-6H,7H,8H-1,3-diazaperhydroino[1,2-h] purine-2,4-dione838894-06-7C19H23N5O2
- 7-(Butan-2-yl)-N-ethyl-6-imino-13-methyl-2-oxo-1,7,9-triazatricyclo[8.4.0.0^{3,8}]tetradeca-3(8),4,9,11,13-pentaene-5-carboxamide842964-80-1C19H23N5O2
- 1-Methyl-3-(2-methylpropyl)-9-phenyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione843670-93-9C19H23N5O2
- 3-Butyl-1-methyl-9-phenyl-6,7,8,9-tetrahydropyrimido[2,1-f]purine-2,4(1H,3H)-dione352640-33-6C19H23N5O2
- 3-Methyl-7-(4-methylbenzyl)-8-(piperidin-1-yl)-1H-purine-2,6(3H,7H)-dione303970-13-0C19H23N5O2
- N-(4-Methylphenyl)-8-(2-pyrimidinyl)-1-oxa-4,8-diazaspiro[4.5]decane-4-carboxamide338761-44-7C19H23N5O2
- 1-Methyl-3-pentyl-8-phenyl-7,8-dihydro-1H-imidazo[2,1-f]purine-2,4(3H,6H)-dione330818-13-8C19H23N5O2
- 6-(4-Ethylphenyl)-4-methyl-2-propyl-7,8-dihydropurino[7,8-a]imidazole-1,3-dione872840-43-2C19H23N5O2
- 6-(3,5-Dimethylphenyl)-4-methyl-2-propyl-7,8-dihydropurino[7,8-a]imidazole-1,3-dione872843-15-7C19H23N5O2
- 2-[(4,8-Dimethylquinazolin-2-yl)amino]-5-(pentan-2-yl)pyrimidine-4,6-diol511514-36-6C19H23N5O2
- 3-Ethyl-1,7-dimethyl-9-(4-methylphenyl)-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione847046-09-7C19H23N5O2
- 9-(3,5-Dimethylphenyl)-1,3,7-trimethyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione845989-73-3C19H23N5O2
- 2-Butyl-4-methyl-6-(2-methylphenyl)-7,8-dihydropurino[7,8-a]imidazole-1,3-dione893962-57-7C19H23N5O2
- 3-Ethyl-1,7-dimethyl-9-(2-methylphenyl)-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione893962-01-1C19H23N5O2
- 3-Isobutyl-1-methyl-8-(m-tolyl)-7,8-dihydro-1H-imidazo[2,1-f]purine-2,4(3H,6H)-dione872840-11-4C19H23N5O2
- 1,3-Dimethyl-7-(3-phenylpropyl)-8-(prop-2-enylamino)purine-2,6-dione377051-26-8C19H23N5O2
- 9-(3,4-Dimethylphenyl)-1,3,7-trimethyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione847368-05-2C19H23N5O2
- 3-Butyl-1-methyl-8-(4-methylphenyl)-1H,2H,3H,4H,6H,7H,8H-imidazo[1,2-g]purine-2,4-dione872840-17-0C19H23N5O2
- 2-Butyl-4-methyl-6-(3-methylphenyl)-7,8-dihydropurino[7,8-a]imidazole-1,3-dione872839-90-2C19H23N5O2
- 8-(2,4-Dimethylphenyl)-1-methyl-3-propyl-1,3,5-trihydroimidazolidino[1,2-h]pur ine-2,4-dione919013-30-2C19H23N5O2
- 8-(2,3-Dimethylphenyl)-1-methyl-3-propyl-1,3,5-trihydroimidazolidino[1,2-h]pur ine-2,4-dione915926-91-9C19H23N5O2
- 9-(2,4-Dimethylphenyl)-3-ethyl-1-methyl-6,7,8,9-tetrahydropyrimido[2,1-f]purine-2,4(1H,3H)-dione923481-78-1C19H23N5O2
- 1,7-Dimethyl-9-phenyl-3-propyl-6,7,8,9-tetrahydropyrimido[2,1-f]purine-2,4(1H,3H)-dione848728-53-0C19H23N5O2
- 1-Cyclopentyl-3-ethyl-6-(3-ethoxy-4-pyridyl)-pyrazolo(3,4-d)pyrimidin-4-one158020-82-7C19H23N5O2
- 2-[(4,6-Dimethylquinazolin-2-yl)amino]-4-hydroxy-5-(3-methylbutyl)-1H-pyrimidin-6-one374771-46-7C19H23N5O2
- 2-[(4,7-Dimethylquinazolin-2-yl)amino]-4-hydroxy-5-pentan-2-yl-1H-pyrimidin-6-one356084-52-1C19H23N5O2
- 9-(3,5-Dimethylphenyl)-3-ethyl-1-methyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione846594-88-5C19H23N5O2
- 3-Ethyl-9-(4-ethylphenyl)-1-methyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione845666-90-2C19H23N5O2
- 1-Methyl-9-(3-methylphenyl)-3-propyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione848214-51-7C19H23N5O2
- 8-(2,5-Dimethylphenyl)-1-methyl-3-propyl-1,3,5-trihydroimidazolidino[1,2-h]pur ine-2,4-dione919032-49-8C19H23N5O2
- 9-(2,3-Dimethylphenyl)-3-ethyl-1-methyl-6,7,8,9-tetrahydropyrimido[2,1-f]purine-2,4(1H,3H)-dione923437-69-8C19H23N5O2
- N-{3-Ethoxy-4-[(1-phenyl-1H-tetrazol-5-yl)oxy]benzyl}propan-1-amine932215-08-2C19H23N5O2
- N-{3-Methoxy-4-[(1-phenyl-1H-tetrazol-5-yl)oxy]benzyl}-2-methylpropan-2-amine931990-86-2C19H23N5O2
- (4-(5-Isopropyl-1,3,4-oxadiazol-2-yl)piperidin-1-yl)(2-methylimidazo[1,2-a]pyridin-3-yl)methanone1209691-25-7C19H23N5O2
- N-Cyclopropyl-2-[6-oxo-3-(4-phenylpiperazin-1-yl)pyridazin-1(6H)-yl]acetamide1185163-41-0C19H23N5O2
- 9-(4-Ethylphenyl)-1,3,7-trimethyl-7,8-dihydro-6H-purino[7,8-a]pyrimidine-2,4-dione848739-17-3C19H23N5O2
- 8-(3,4-Dimethylphenyl)-1-methyl-3-propyl-1H,2H,3H,4H,6H,7H,8H-imidazo[1,2-g]purine-2,4-dione872842-85-8C19H23N5O2
- 2-[(4,6-Dimethylquinazolin-2-yl)amino]-5-(pentan-2-yl)pyrimidine-4,6-diol524055-90-1C19H23N5O2
- 1-Butyl-2-imino-N~3~-isopropyl-5-oxo-1,5-dihydro-2H-dipyrido[1,2-a:2,3-d]pyrimidine-3-carboxamide848065-19-0C19H23N5O2
- 1H-Purine-2,6-dione, 3,7-dihydro-1,3-diethyl-8-(2-(4-(dimethylamino)phenyl)ethenyl)-, (E)-155271-92-4C19H23N5O2
- 2-(1-tert-Butyl-4-oxopyrazolo[3,4-d]pyrimidin-5-yl)-N-(2,3-dimethylphenyl)acetamide863447-67-0C19H23N5O2
- 2-(1-(tert-Butyl)-4-oxo-1H-pyrazolo[3,4-d]pyrimidin-5(4H)-yl)-N-(2,5-dimethylphenyl)acetamide863447-68-1C19H23N5O2
- 2-(1-tert-Butyl-4-oxopyrazolo[3,4-d]pyrimidin-5-yl)-N-(2,4-dimethylphenyl)acetamide863447-69-2C19H23N5O2
- 2-(1-tert-Butyl-4-oxopyrazolo[3,4-d]pyrimidin-5-yl)-N-(3,5-dimethylphenyl)acetamide863447-70-5C19H23N5O2
- 2-(1-(tert-Butyl)-4-oxo-1H-pyrazolo[3,4-d]pyrimidin-5(4H)-yl)-N-(4-ethylphenyl)acetamide863447-72-7C19H23N5O2
- 3,7-Dimethyl-1-(4-methylbenzyl)-8-(pyrrolidin-1-yl)-1H-purine-2,6(3H,7H)-dione919020-22-7C19H23N5O2
- 1-[(2,5-Dimethylphenoxy)methyl]-N-methyl-N-[(1-methyl-1H-pyrazol-5-yl)methyl]-1H-pyrazole-3-carboxamide1005692-48-7C19H23N5O2
- 2-(4-Ethylpiperazine-1-carbonyl)-1,7-dimethylpyrido[1,2-a]pyrrolo[2,3-d]pyrimidin-4(1H)-one946202-99-9C19H23N5O2
- N-tert-Butyl-2-[2-(4-ethylphenyl)-4-oxopyrazolo[1,5-d][1,2,4]triazin-5(4H)-yl]acetamide1291853-00-3C19H23N5O2
- 4-Benzyl-N-[2-oxo-2-(pyridin-3-ylamino)ethyl]piperazine-1-carboxamide1232784-87-0C19H23N5O2
- 5-Oxo-N-(3-pyridyl)-5-[4-(2-pyridyl)piperazino]pentanamide1246074-68-9C19H23N5O2
- 1-(4-(Pyrimidin-2-yl)piperazin-1-yl)-2-((5,6,7,8-tetrahydroquinolin-4-yl)oxy)ethanone1787883-38-8C19H23N5O2
- (3-(Dimethylamino)phenyl)(2-morpholino-5H-pyrrolo[3,4-d]pyrimidin-6(7H)-yl)methanone2034273-30-6C19H23N5O2
- N-[3-(2-Methylpropyl)-1H-1,2,4-triazol-5-yl]-1-oxo-2-(propan-2-yl)-1,2-dihydroisoquinoline-4-carboxamide1630904-52-7C19H23N5O2
- 2-[(4,6-Dimethyl-2-pyrimidinyl)amino]-N-[2-(5-methoxy-1H-indol-1-yl)ethyl]acetamide1630862-46-2C19H23N5O2
- 1-[(2,5-Dimethylphenoxy)methyl]-N-[(1,5-dimethylpyrazol-4-yl)methyl]pyrazole-3-carboxamide1005647-68-6C19H23N5O2
- N-(2,3-Dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)-1-methyl-3-propyl-1H-pyrazole-5-carboxamide956614-60-1C19H23N5O2
- 2-[1-(2,4-Dimethylphenyl)-4-oxopyrazolo[3,4-d]pyrimidin-5-yl]-N,N-diethylacetamide895002-11-6C19H23N5O2
- N-{1-tert-Butyl-4-oxo-1H,4H,5H-pyrazolo[3,4-d]pyrimidin-5-yl}-2-phenylbutanamide899995-85-8C19H23N5O2
- N-(4-Oxo-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-5(4H)-yl)-2-propylpentanamide899945-82-5C19H23N5O2
- N-(1-(3,4-Dimethylphenyl)-4-oxo-1H-pyrazolo[3,4-d]pyrimidin-5(4H)-yl)-2-ethylbutanamide900008-52-8C19H23N5O2
- 1,3-Dimethyl-7-(1-phenylethyl)-8-(pyrrolidin-1-yl)-1H-purine-2,6(3H,7H)-dione1105244-63-0C19H23N5O2
- 2-(1H-1,3-Benzodiazol-1-yl)-1-{4-[5-(propan-2-yl)-1,3,4-oxadiazol-2-yl]piperidin-1-yl}ethan-1-one1209233-69-1C19H23N5O2
- N-[3-(4-Benzylpiperazino)-3-oxopropyl]-2-pyrazinecarboxamide1374531-10-8C19H23N5O2
- 5-(2-Oxo-2-piperidin-1-ylethyl)-1-propyl[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one1358309-51-9C19H23N5O2
- 1-Isopropyl-5-(2-oxo-2-piperidinoethyl)[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one1359066-50-4C19H23N5O2
- N-{2-Oxo-2-[(pyridin-3-ylmethyl)amino]ethyl}-4-phenylpiperazine-1-carboxamide1324059-54-2C19H23N5O2
- N-{2-Oxo-2-[(pyridin-4-ylmethyl)amino]ethyl}-4-phenylpiperazine-1-carboxamide1351681-78-1C19H23N5O2
Frequently asked questions
What is the molar mass of C19H23N5O2?
The molar mass of C19H23N5O2 is 353.43 g/mol, calculated from standard atomic weights for 19 carbon atoms, 23 hydrogen atoms, 5 nitrogen atoms and 2 oxygen atoms. The monoisotopic mass is 353.1852 Da.
How many compounds have the formula C19H23N5O2?
CompoundList lists 216 compounds with the molecular formula C19H23N5O2, including Epiroprim, 7-Benzyl-3-methyl-8-(4-methylpiperidin-1-yl)-1H-purine-2,6(3H,7H)-dione, 8-(Cyclopentylamino)-3-methyl-7-(3-methylbenzyl)-1H-purine-2,6(3H,7H)-dione. 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 C19H23N5O2?
C19H23N5O2 has a degree of unsaturation of 11. 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.