!!!! Porphine and porphyrin

==== Wikipedia

https://en.wikipedia.org/wiki/Porphyrin @@ Porphyrin
https://en.wikipedia.org/wiki/Porphine @@ Porphine
https://en.wikipedia.org/wiki/Hexahydroporphine @@ Hexahydroporphine
https://en.wikipedia.org/wiki/2,5-Bis(hydroxymethyl)pyrrole @@ 2,5-Bis(hydroxymethyl)pyrrole
https://en.wikipedia.org/wiki/Hydroxymethylbilane @@ Hydroxymethylbilane
https://en.wikipedia.org/wiki/Heme @@ Heme
https://en.wikipedia.org/wiki/Uroporphyrinogen_III @@ Uroporphyrinogen_III
https://en.wikipedia.org/wiki/Protoporphyrin_IX @@ Protoporphyrin_IX

==== References 
https://www.osti.gov/servlets/purl/4367430 @@ Gilber Seely thesis on photochemistry
https://pubs.acs.org/doi/abs/10.1021/ja00966a042?journalCode=jacsat @@ Hypocholophyll
https://aip.scitation.org/doi/abs/10.1063/1.1743651 @@ Molecular orbitals of porphyrins
https://pubs.rsc.org/en/content/articlelanding/1957/jr/jr9570003461/unauth#!divAbstract@Novel hydroporphyrins
https://pubs.acs.org/doi/abs/10.1021/ja01143a508?journalCode=jacsat @@ Attempt tetrahydroporphine
https://link.springer.com/article/10.1007%2FBF00662577?LI=true @@ isomers of tetrahydroporphin
https://aip.scitation.org/doi/abs/10.1063/1.1700541?journalCode=jcp @@ Electron model of porphine and TH porphine
https://aip.scitation.org/doi/abs/10.1063/1.1747907 @@ Orbitals porphine and TH porphine
https://www.sciencedirect.com/science/article/pii/0006291X73908917 @@ Iron TH porphyrin
https://scholar.google.com.br/scholar?start=10&q=hexahydroporphin&hl=en&as_sdt=0,5 @@ GoogleScholar HH prophin
http://adsabs.harvard.edu/abs/1985OptSp..59..296A @@ Luminescence of TH porphin in octane
https://link.springer.com/article/10.1007%2FBF00657464?LI=true Absorption spectrum of TH porphine
https://aip.scitation.org/doi/10.1063/1.1700541 @@ Free electrons of porphine and TH porphine