Mo. Senge et al., CRYSTAL-STRUCTURE OF A REMARKABLY RUFFLED NONPLANAR PORPHYRIN [5,10,15,20-TETRA(TERT-BUTYL)PORPHYRINATO]ZINC(II), Journal of the Chemical Society, Chemical Communications, (7), 1995, pp. 733-734
The title compound presents the first example of a sterically ruffled
porphyrin bearing only meso substituents; the degree of ruffling is se
vere, with C-m-displacements of up to 1 Angstrom.