title: Efficient screening of 2D molecular polymorphs at the solution-solid interface.
abstract: Formation of multiple polymorphs during two-dimensional (2D) crystallization of organic molecules is more of a routine occurrence than rarity. Although such diverse crystalline structures provide exciting possibilities for studying crystal engineering in 2D, predicting the occurrence of polymorphs for a given building block is often non-trivial. Moreover, there is scarcity of methods that can experimentally verify the presence of such crystalline polymorphs in a straightforward fashion. Here we demonstrate a relatively simple experimental approach for screening of 2D polymorphs formed at the solution-solid interface. The strategy involves use of solution flow produced by contacting a piece of tissue paper to the sample to generate a lateral density gradient along the substrate surface. In situ generation of such gradient allows rapid discovery and nanoscale separation of multiple 2D polymorphs in a single experiment. The concept is demonstrated using three structurally different building blocks that differ in terms of intermolecular interactions responsible for 2D crystal formation. The method described here represents a powerful tool for efficient screening of 2D polymorphs formed at the solution-solid interface.
authors.affiliation: Department of Chemistry, Division of Molecular Imaging and Photonics, KU Leuven-University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium. Kunal.Mali@chem.kuleuven.be Steven.DeFeyter@chem.kuleuven.be.
authors.forename: Shern-Long
authors.initials: SL
authors.lastname: Lee
authors.forename: Jinne
authors.initials: J
authors.lastname: Adisoejoso
authors.forename: Yuan
authors.initials: Y
authors.lastname: Fang
authors.forename: Kazukuni
authors.initials: K
authors.lastname: Tahara
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tobe
authors.forename: Kunal S
authors.initials: KS
authors.lastname: Mali
authors.forename: Steven
authors.initials: S
authors.lastname: De Feyter