Chlorin

Not to be confused with chlorine.

Chlorin
Identifiers
CAS number	2683-84-3 Y
PubChem	65106
ChemSpider	58616 Y
ChEBI	CHEBI:36303 N
Jmol-3D images	Image 1
SMILES n3c4cc5nc(cc\1nc(/C=C/1)cc2ccc(n2)cc3CC4)cc5
InChI InChI=1S/C20H16N4/c1-2-14-10-16-5-6-18(23-16)12-20-8-7-19(24-20)11-17-4-3-15(22-17)9-13(1)21-14/h1-6,9-12,22-23H,7-8H2/b13-9-,14-10-,15-9-,16-10-,17-11-,18-12-,19-11-,20-12- Y Key: UGADAJMDJZPKQX-CEVVSZFKSA-N Y InChI=1/C20H16N4/c1-2-14-10-16-5-6-18(23-16)12-20-8-7-19(24-20)11-17-4-3-15(22-17)9-13(1)21-14/h1-6,9-12,22-23H,7-8H2/b13-9-,14-10-,15-9-,16-10-,17-11-,18-12-,19-11-,20-12- Key: UGADAJMDJZPKQX-CEVVSZFKBJ
Properties
Molecular formula	C20H16N4
Molar mass	312.36784
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

In organic chemistry, a chlorin is a large heterocyclic aromatic ring consisting, at the core, of three pyrroles and one pyrroline coupled through four methine linkages. Unlike porphin, the central aromatic ring structure of porphyrins, a chlorin is therefore largely aromatic but not aromatic through the entire circumference of the ring.

Magnesium-containing chlorins are called chlorophylls, and are the central photosensitive pigment in chloroplasts.

Structures comparing porphin, chlorin, and bacteriochlorin

Related compounds, with two reduced pyrroles, are called bacteriochlorins and isobacteriochlorins.

Because of their photosensitivity, chlorins are in active use as photosensitizing agents in experimental photodynamic therapy.

Chlorin is not to be confused with the chemical element chlorine.

See also

• Corrin
• Photodynamic therapy