meso-5,10,15,20-Tetra-kis(4-hy-droxy-3-meth-oxy-phen-yl)porphyrin propionic acid monosolvate.

In the title compound, C(48)H(38)N(4)O(8)·C(3)H(6)O(2), the porphyrin mol-ecule is centrosymmetric. The propionic acid solvent mol-ecule is disordered over two sets of sites with equal occupancy factors. The porphyrin central core is almost planar, with an r.m.s. deviation of the fitted atoms of 0.045 Å. The substituent benzene rings make dihedral angles of 70.37 (4) and 66.95 (4)° with respect to the porphyrin core plane. The crystal structure is stabilized by an inter-esting network of hydrogen bonds. Porphyrin mol-ecules are connected by O-H⋯O hydrogen bonds creating ribbons running along the [101] direction. Weak C-H⋯O hydrogen bonds connect separate mol-ecular ribbons in the [110] direction, creating (-111) layers. Intra-molecular N-H⋯N hydrogen bonds also occur. The propionic acid molecules are connected by pairs of -H⋯O hydrogen bonds, creating dimers.