Conformational study of 2,3,5,7,8,12,13,15,17,18-decaalkylporphyrins

Authors :: Medforth, Craig J.
Senge, Mathias O.
Forsyth, Timothy P.
Hobbs, J. David
Shelnutt, John A.
Smith, Kevin M.
Source :: Inorganic Chemistry. August 31, 1994, Vol. 33 Issue 18, p3865, 8 p.
Publication Year :: 1994
Abstract: X-ray studies of 3,5,7,13,15,17-hexaethyl-2,8,12,18-tetramethylporphyrin (H2DAP) crystals reveal an elongated planar macrocycle along the 5,15 axis that cancels the steric interference of the meso and pyrrole ethyl groups. Another decaalkylporphyrin NiDAP, reveals nonplanar distortion in the porphyrin unit to relieve steric crowding. Optical spectroscopy, NMR and MO calculations help examine solution conformations of H2DAP and NiDAP. Low-temperature NMR studies reveal cis and trans conformation of the methyl groups of the meso ethyls in H2DAP and ZnDAP.