Synthesis and Retrostructural Analysis of Libraries of AB3 and Constitutional Isomeric AB2 Phenylpropyl Ether-Based Supramolecular Dendrimers

We report the synthesis of methyl esters of 3- (4-hydroxyphenyl) propionic, 3- (3, 4-dihydroxyphenyl) propionic, 3- (3, 5-dihydroxyphenyl) propionic, and 3- (3, 4, 5-trihydroxyphenyl) propionic acids and their use in a convergent iterative strategy to prepare up to four generations of three libraries, one of 3, 4, 5- and two of constitutional isomeric 3, 4- and 3, 5-substituted 3-phenylpropyl dendrons. Each library contains 3-3, 4, 5-tris (dodecyl-1-oxy) phenylpropyl-, 3-3, 4-bis (dodecyl-1-oxy) phenylpropyl-, 3-3, 4-bis3- (4-dodecyl-1-oxyphenyl) propyl-1-oxyphenylpropyl-, and 3-3, 4, 5-tris3- (4-dodecyl-1-oxyphenyl) propyl-1-oxyphenylpropyl ether first-generation dendrons on their periphery and -CO2CH3, -COOH, and -CH2OH groups at their apex. Regardless of their generation number and their periphery, internal, and apex structures, these dendrons self-assemble into supramolecular dendrimers that self-organize into all periodic and quasi-periodic assemblies encountered previously and in several unencountered with architecturally related benzyl ether-based supramolecular dendrimers. A variety of porous columnar lattices that were previously obtained only from dendritic dipeptides and hollow supramolecular spheres were also discovered from these building blocks. The more flexible and less compact 3-phenylpropyl ether repeat units are stable under acidic conditions, facilitate a simpler synthetic strategy, provide faster dynamics of self-assembly into higher-order supramolecular structures of larger dimensions, exhibit lower transition temperatures than the corresponding benzyl ether homologues, and demonstrate the generality of the self-assembly concept based on amphiphilic dendrons.