Non-Negligible Modulation Role of the Solvent in the Asymmetric Growth of α‑Resorcinol

It is accepted that the asymmetric growth of α-resorcinol is an intrinsic property and the solvent only plays a secondary role. Therefore, this work combines single-crystal growth experiments and molecular dynamics simulations to quantify the non-negligible modulation role of the solvent in the asymmetric growth of α-resorcinol. According to the experimental results, the growth rate ratio of α-resorcinol in water is the largest, followed by that in ethyl acetate, and ethanol had the least influence. The (01̅1̅) face along the polar −c axis is a hydroxyl-rich surface, and the capability of hydrogen bond formation determines the magnitude of the growth rate. However, the (011) face along the polar +c axis is a hydrogen-rich surface, and the growth rate mainly depends on the molecular structure of the crystalline surface and the steric hindrance between molecules. In general, the molecular arrangement of α-resorcinol along both ends of the polar c-axis makes the solvent exhibit significant modulation differences in the asymmetric growth, which are entirely attributed to the mechanisms of solvent action on the specific crystalline surface. This work will further enrich the asymmetric growth mechanism of α-resorcinol in solution and potentially provide some guidance for the selection of the solvent for other organic polar crystals.