Reverse Anti-solvent Crystallization Process for the Facile Synthesis of Zinc Tetra(4-pyridyl)porphyrin Single Crystalline Cubes

Yohwan Park,Taiha Joo,Hee Cheul Choi,Jinho Lee,Hyunseob Lim,Minkyung Lee,Jin Young Koo,Misun Hong,Woo Taik Lim,Dae Jun Moon,So Hyeong Sohn

doi:10.1038/s41598-017-02718-9

Abstract

Synthesis of morphologically well-defined crystals of metalloporphyrin by direct crystallization based on conventional anti-solvent crystallization method without using any additives has been rarely reported. Herein, we demonstrate an unconventional and additive-free synthetic method named reverse anti-solvent crystallization method to achieve well-defined zinc-porphyrin cube crystals by reversing the order of the addition of solvents. The extended first solvation shell effect mechanism is therefore suggested to support the synthetic process by providing a novel kinetic route for reaching the local supersaturation environment depending on the order of addition of solvents, which turned out to be critical to achieve clean cube morphology of the crystal. We believe that our work not only extends fundamental knowledge about the kinetic process in binary solvent systems, but also enables great opportunities for shape-directing crystallization of various organic and organometallic compounds.

Highlights

Interactions or by minimizing the surface energy of certain crystal planes
We first attempted the c-ASC method for ZnTPyP powder solutes with isopropyl alcohol (IPA) as a good solvent, and toluene as an anti-solvent
A quite unexpected result was found, in which no precipitation was observed during this process (Fig. S1). This is because the addition of an anti-solvent into a solution saturated with solutes in a good solvent generally induces the decrease of the total solubility of the solute in a binary solvent system, which readily results in prompt precipitation

Summary

Introduction

Interactions or by minimizing the surface energy of certain crystal planes. It is clear, that the addition of extra chemicals should be minimized in order to maintain the original properties of the target crystals. In advance of the conventional FSSE mechanism, we suggest an extended FSSE mechanism that is suitable to explain the critical role of the type of solvation solvent regardless of the species of solvents (e.g., polar and non-polar solvents) that can be controlled by changing the solvent-addition order. This suggests a new kinetic route for reaching the local supersaturation environment and enables shape-specific crystal synthesis

Methods

Results

Conclusion