Synthesis of single-crystal tetra(4-pyridyl)porphyrin rectangular nanotubes in the vapor phase.

Stacking up: One-dimensional single-crystalline rectangular nanotubes (RNTs) of 5,10,15,20-tetra(4-pyridyl)porphyrin (H(2)TPyP, see picture) are synthesized by a vaporization-condensation-recrystallization process. The single-crystal X-ray diffraction and selected-area electron diffraction data reveal that the H(2)TPyP RNTs form by self-stacking of H(2)TPyP units through hydrogen-bonding, H-pi, and pi-pi intermolecular interactions.