meso-Tetrathienylporphyrins:: Steady-state emission and structural properties

meso-Tetra (2'- and 3'-thienyl)porphyrins and their Zn(II)-complexes were examined by steadystate fluorescence measurements. These molecules exhibit significant bathochromic shift in their emission bands with decreased quantum yields relative to their corresponding meso-tetraphenylporphyrin derivatives. The crystal structure of 5,10,15,20-tetrakis(3'-thienyl)porphinato zinc(II) shows planar and nonplanar stereochemical features of the macrocycle. One of the macrocycle shows nearly planar while the other exhibited predominantly saddle-shaped geometry. The extent of displacement of the beta-pyrrole carbons in the nonplanar (saddle) conformation is as high as +/- 0.422 angstrom.