Nanoscopic Imaging of meso‐Tetraalkylporphyrins Prepared in High Yields Enabled by Montmorrilonite K10 and 3 Å Molecular Sieves

Abstract

We have developed a high-yielding synthesis of meso-tetraalkylporphyrins, which previously have been obtained only in lower yields. By employing Montmorrilonite K10 as the acid catalyst and 3 Å molecular sieves as the dehydrating agent, yields that reached 70 % could be achieved with some aliphatic aldehydes. The free-base porphyrins with decyl (C10) or longer chains were imaged at the single-molecule level at the solvent/surface interface. Highly oriented pyrolytic graphite (HOPG) was used as a π-stacking surface, whereas 1-phenyloctane and 1-phenylnonane were used as solvents. An odd-even effect was observed from C13 to C16. For C13 a single-crystal X-ray structure allowed an unprecedented insight into how packing from two dimensions is expanded into a three-dimensional crystal lattice.

Siamese‐Twin Porphyrins: Variation of Two meso‐Aryl Groups

“…Even though the electronic effects of various meso ‐aryl substituents are small, they are not negligible . meso ‐Alkylporphyrins are also electronically much distinct from their meso ‐aryl congeners …”

Crystal structure, magnetic and catalytic oxidation properties of manganese(iii) tetrakis(ethoxycarbonyl)porphyrin

“…34,35 Meso-tetraalkyl porphyrins are useful probes for understanding the structure-property relationship of porphyrin molecules. 36 Although tetraalkylporphyrins may be prepared with good yields, [37][38][39] there is the less reports on the application of manganese tetraalkylporphyrin in catalytic oxidation. 40,41 5,10,15,20-tetrakis(ethoxycarbonyl)porphyrin (TECP) is a convenient precursor for porphine.…”

Stepwise Preparation of meso‐Tetraphenyl‐ and meso‐Tetrakis(4‐trifluoromethylphenyl)bacteriodilactones and their Zinc(II) and Palladium(II) Complexes

“…meso ‐Tetraphenylporpholactone 1a can be made in modest yields from tetraphenylporphyrin 2a in one single step only using the RuCl 3 /Oxone®/bipy methodology, but this method does not produce any dilactones, even when harsher conditions are used (increase of stoichiometric ratio of catalyst, terminal oxidant, or lengthening the reaction time; see Supporting Information). Tetraphenylporphyrin 2a is inert to all other methods (as are meso ‐tetra‐ n ‐alkylporphyrins (see Supporting Information Table S1) . In contrast, the corresponding conversion of meso ‐tetrakis(pentafluorophenyl)porphyrin 2c to monolactone 1c using the same conditions is more efficient (45 % yield for 2a vs. 30 % yield for 2c ) and some dilactones 3c are readily formed (ca.…”