Boosting Self‐Assembly Diversity in the Solid‐State by Chiral/Non‐Chiral Zn^II‐Porphyrin Crystallization

Abstract

A chiral Zn porphyrin derivative 1 and its achiral analogue 2 were studied in the solid state. Considering the rich molecular recognition of designed metalloporphyrins 1 and 2 and their tendency to crystallize, they were recrystallized from two solvent mixtures (CH Cl /CH OH and CH Cl /hexane). As a result, four different crystalline arrangements (1 a,b and 2 a,b, from 0D to 2D) were obtained. Solid-state studies were performed on all the species to analyze the role played by chirality, solvent mixtures, and surfaces (mica and HOPG) in the supramolecular arrangements. By means of combinations of solvents and substrates a variety of microsized species was obtained, from vesicles to flower-shaped arrays, including geometrical microcrystals. Overall, the results emphasize the environmental susceptibility of metalloporphyrins and how this feature must be taken into account in their design.

Chiral porphyrin assemblies

“…Various types of chiral porphyrins aside from steroidand sugar-modified porphyrins have been designed. [19][20][21][22][23][24][25] For instance, Meijer et al systemically studied the pathway complexity of the supramolecular polymerization of a chiral porphyrin. [26] A chiral amide-functionalized zinc porphyrin (S/R)-1 (Figure 1) was designed, and hydrogen bonding between the amide moiety and π-π stacking of the porphyrin skeleton was attributed to the formation of supramolecular polymers.…”

“…Various types of chiral porphyrins aside from steroid‐ and sugar‐modified porphyrins have been designed. [ 19–25 ] For instance, Meijer et al. systemically studied the pathway complexity of the supramolecular polymerization of a chiral porphyrin.…”

Stereospecific Self-Assembly Processes of Porphyrin-Proline Conjugates: From the Effect of Structural Features and Bulk Solvent Properties to the Application in Stereoselective Sensor Systems

“…Moreover, we found that the presence of 100-fold molar excess of external nitrogen ligands, i.e., (R)- and (S)-1-phenylethylamine, dictated the stereochemical course of the self-assembly process, disregarding the stereochemistry of the L- or D-proline functionalities ( Figure 6 a) [ 73 ]. Furthermore, the species formed using an achiral ligand (i.e., benzylamine) no longer showed supramolecular chirality.…”

“…SEM images of ZnP(L)Pro(−) aggregates (10 μM; EtOH/H 2 O 25/75 v:v) in the presence of (R)-phenylethylamine (1 mM) ( b ) and without added nitrogen ligand ( c ). Adapted from OPEN ACCESS [ 73 ].…”

Broadening the scope of high structural dimensionality nanomaterials using pyridine-based curcuminoids

“…Related types of shapes are reported studying the effect of solvent and surfaces on some CP dispersions, showing that crystals are formed by domains that can disaggregate. 33 AFM topographic images, using the tapping mode for the SiO 2 /Si wafers, are shown in Fig. 8.…”