Process Development for Separation of Conformers from Derivatives of Resorcin[4]arenes and Pyrogallol[4]arenes

Abstract

Macrocyclic compounds, such as resorcin[4]arenes and pyrogallol[4]arenes, have proven to be useful building blocks in the construction of supramolecular organic frameworks (SOFs) because of their unique bowl-like shape and ability to interact through variety of intermolecular interactions. Herein, we report the synthesis and crystal structures of two functionalized resorcin[4]arenes and pyroagllol[4]arenes, 4-hydroxyphenylresorcin[4]arenes, and 4-hydroxyphenylpyrogallol[4]arenes. These phenyl-functionalized macrocycles usually have different conformers, such as cone, boat, chair, saddle, and diamond. The successful separation of predominant conformers from the crude product was carried out with solvent-extraction technique. The shape and molecular arrangement of these conformers in the individual crystal structure was verified with single-crystal X-ray diffraction studies.

Incorporation of a p‐Phenylene Unit into the Azuliporphyrinogens Frame—Oxidation and Ruthenium Cluster Coordination

“…As a matter of fact such a modification leads to an expansion of macrocyclic frame and increases a number of carbon atoms in the cavity. Due to the presence of four C(sp 3 ) meso bridges introducing additional degrees of freedom the molecule can remain in a few distinguished conformations influencing appropriate crystal structures of such systems or coordination properties of isomers …”

Highly stable polyoxometalate‐resorcin[4]arene‐based inorganic‐organic complexes for catalytic oxidation desulfurization

“…For example, the chelating ligands potentially support the stability of the resulting complexes . In this regard, functionalized resorcin[4]arenes, showing bowl‐shaped aromatic cavities, are well‐known macrocyclic ligands and excellent candidates for assembly of stable POMs‐based inorganic–organic hybrid complexes …”

Formation of Water Channels in the Crystalline Hydrates of Macrocyclic Compounds

“…However the presence of bulky sulfonato groups hinders the interaction of guest molecules with upper‐rim hydroxy groups. Another approach to improve water solubility is functionalization at the lower C ‐alkyl tail or at the bridged methine group of RsC/PgC . Previous studies also demonstrated the formation of cogged hexameric nanotubular architecture from PgCs with unique branched alkyl tails .…”

“…However, functionalization at the bridged methine group, especially phenyl functionalization, may be associated with the formation of a mixture of conformers such as cone, boat, chair, saddle, and diamond . Separation of major conformers has been achieved with solvent extraction methods . Functionalization of the lower rim of RsC/PgC thus produces distinct framework architecture in the crystalline state as well as multiple conformers .…”

“…The crude product of the synthesis of 4‐OHPhPgC and 4‐OHPhRsC contains mixture of two major conformers such as chair and cone/boat. Thus, the separation of conformer is carried out with the previously reported solvent extraction method . This purification and separation method produces the boat/cone conformer of 4‐OHPhPgC and 4‐OHPhRsC with high purity (Figures S3 and S4).…”