Stacked porphyrin arrays from hydrogen-bonded porphyrin-resorcinol 1D chains

The Ni(II) complex of monoresorcinol derivative of a sterically unhindered tetraalkylporphyrin (3) affords adducts 3 . (methanol) and 3 .1.5(acetophenone). In the crystals, porphyrin 3 forms hydrogen-bonded (O-H . . .O-H) polyresorcinol chains with the porphyrin residues sticking out of the chains. The chains are self-assembled in such a manner as to give closely stacked interchain porphyrin columns, while the guest molecules are either firmly bound to the hydrogen-bonding sites (in the case of methanol) or incorporated in the channels running in parallel with the porphyrin stacks (in the case of acetophenone). The formation of such a stacked porphyrin array is not observed when the guest is changed to 4-heptanone or when the porphyrin is changed to a sterically hindered one 4 or 5 with full substitution at the meso- or the beta -positions. The mode of interchain porphyrin stacking is discussed in light of the crystal structures of adducts 3 . (4-heptanone), 4 . pyridine, and 5 . (2-nonanone).