title: Precrystalline Aggregates Enable Control over Organic Crystallization in Solution.
abstract: Understanding and controlling organic crystallization in solution is a long-standing challenge. Herein, we show that crystallization of an aromatic amphiphile based on perylene diimide in aqueous media involves initially formed amorphous spherical aggregates that evolve into the crystalline phase. The initial appearance of the crystalline order is always confined to the spherical aggregates that are precursors for crystalline evolution. The change in the solvation of the prenucleation phase drives the crystallization process towards crystals that exhibit very different structure and photofunction. The initial molecular structure and subsequent crystal evolution can be regulated by tuning the hydrophobicity at various stages of crystallization, affording dissimilar crystalline products or hindering crystallization. Thus, the key role of the precrystalline states in organic crystal evolution enables a new strategy to control crystallization by precrystalline state manipulation.
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel) http://www.weizmann.ac.il/oc/boris/
authors.forename: Chen
authors.initials: C
authors.lastname: Shahar
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel) http://www.weizmann.ac.il/oc/boris/
authors.forename: Sounak
authors.initials: S
authors.lastname: Dutta
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel) http://www.weizmann.ac.il/oc/boris/
authors.forename: Haim
authors.initials: H
authors.lastname: Weissman
authors.affiliation: Department of Chemical Research Support, Weizmann Institute of Science (Israel).
authors.forename: Linda J W
authors.initials: LJ
authors.lastname: Shimon
authors.affiliation: Bruker AXS GmbH, Östliche Rheinbrückenstrasse 49, 76187 Karlsruhe (Germany).
authors.forename: Holger
authors.initials: H
authors.lastname: Ott
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel) http://www.weizmann.ac.il/oc/boris/. boris.rybtchinski@weizmann.ac.il.
authors.forename: Boris
authors.initials: B
authors.lastname: Rybtchinski
keywords: crystallization; hydrophobic interactions; perylene diimide; polymorphism; prenucleation