Synthesis of Capped Tetrachelate Porphyrins: Towards “Insulation” of the Chromophore on Semiconductor Surfaces

Abstract

AbstractA novel “capped” metal‐free tetraphenylporphyrin 1, was synthesized and characterized. The cap was designed to “insulate” the chromophoric unit and prevent aggregation as well as undesired contacts on the semiconductor surface. The cap was made of a benzene unit linked by four methylenic units (‐(CH2)4−) to the meso‐phenyl ring of the porphyrin core through an ether group. The COOMe groups are in meta position for an ideal bite angle to the semiconductor surface and the constrain imposed by the cap avoids conformational freedom of the anchoring groups. The 1H NMR spectrum of 1 suggests that the metal free macrocycle 1 is distorted from planarity. The solution UV‐Vis and fluorescence emission spectra of 1 were typical of a metal‐free tetraphenylporphyrin.