Octaethylporphyrin (H2OEP) is an organic compound that is a relative of naturally occurring heme pigments. The compound is used in the preparation of models for the prosthetic group in heme proteins. It is a dark purple solid that is soluble in organic solvents. As its conjugate base OEP2-, it forms a range of transition metal porphyrin complexes. When treated with ferric chloride in hot acetic acid solution, it gives the square pyramidal complex Fe(OEP)Cl.[1] It also forms the square planar complexes Ni(OEP) and Cu(OEP).

Octaethylporphyrin
Names
Other names
2,3,7,8,12,13,17,18-Octaethyl-21H,23H-porphine
Identifiers
3D model (JSmol)
379798
ChEBI
ChemSpider
EC Number
  • 220-243-8
UNII
  • InChI=1S/C36H46N4/c1-9-21-22(10-2)30-18-32-25(13-5)26(14-6)34(39-32)20-36-28(16-8)27(15-7)35(40-36)19-33-24(12-4)23(11-3)31(38-33)17-29(21)37-30/h17-20,37,40H,9-16H2,1-8H3/b29-17-,30-18-,31-17-,32-18-,33-19-,34-20-,35-19-,36-20-
    Key: HCIIFBHDBOCSAF-MUZKIALCSA-N
  • CCC1=C(C2=CC3=NC(=CC4=C(C(=C(N4)C=C5C(=C(C(=N5)C=C1N2)CC)CC)CC)CC)C(=C3CC)CC)CC
Properties
C36H46N4
Molar mass 534.792 g·mol−1
Appearance purple solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Saturated solution of H2OEP in dichloromethane.

Contrast with other porphyrins

edit

Unlike complexes of the naturally occurring porphyrins, OEP complexes have four-fold symmetry, which simplifies spectroscopic analysis. In contrast to tetraphenylporphyrin and related analogues, H2OEP features unprotected meso positions. In this way, it is a more accurate model for naturally occurring porphyrins.

Synthesis

edit

H2OEP is prepared by condensation of 3,4-diethylpyrrole with formaldehyde.[2]

References

edit
  1. ^ Chang, C. K.; DiNello, R. K.; Dolphin, D. (1980). "Iron Porphines". Inorg. Synth. 20: 147. doi:10.1002/9780470132517.ch35.
  2. ^ Sessler, Jonathan L.; Mozaffari, Azadeh; Johnson, Martin R. (1992). "3,4-Diethylpyrrole and 2,3,7,8,12,13,17,18-Octaethylporphyrin". Org. Synth. 70: 68. doi:10.15227/orgsyn.070.0068.