Combinatorial Crystal Synthesis: Structural Landscape of Phloroglucinol:1,2‐bis(4‐pyridyl)ethylene and Phloroglucinol:Phenazine

Abstract

A large number of crystal forms, polymorphs and pseudopolymorphs, have been isolated in the phloroglucinol-dipyridylethylene (PGL:DPE) and phloroglucinol-phenazine (PGL:PHE) systems. An understanding of the intermolecular interactions and synthon preferences in these binary systems enables one to design a ternary molecular solid that consists of PGL, PHE, and DPE, and also others where DPE is replaced by other heterocycles. Clean isolation of these ternary cocrystals demonstrates synthon amplification during crystallization. These results point to the lesser likelihood of polymorphism in multicomponent crystals compared to single-component crystals. The appearance of several crystal forms during crystallization of a multicomponent system can be viewed as combinatorial crystal synthesis with synthon selection from a solution library. The resulting polymorphs and pseudopolymorphs that are obtained constitute a crystal structure landscape.

Exploring the Crystal Structure Landscape with a Heterosynthon Module: Fluorobenzoic Acid:1,2-Bis(4-pyridyl)ethylene 2:1 Cocrystals

“…the pool of synthons having comparable energy and directionality. 31 With insulation of the primary supramolecular synthon, smooth secondary synthon interchangeability maintains a similar hydrogen-bonding pattern which further leads to comparable three-dimensional crystal structures ( Figure 3). …”

“…DPE-I, 35DFBA:DPE-I, 235TFBA:DPE-I, 236TFBA:DPE-I (3-11-26) Crystal Growth & Designnuclei, secondary recognition preferences may be amplified from the pool of synthons that finally lead to similar crystal structures 31. Moving further, the 25DFBA:DPE-I, 35DFBA:DPE-I, 235TFBA:DPE-I, and 236TFBA:DPE-I crystal structures constitute the(3-11-26) type.…”

Systematic Construction of Ternary Cocrystals by Orthogonal and Robust Hydrogen and Halogen Bonds

“…14 The strategy was later shown to be a general one, using different components selected based on the same principles. [15][16][17] A great body of work on the preparation of ternary [18][19][20][21][22] and even quaternary 23,24 co-crystals has been recently reported by Desiraju and co-workers. First, a shapebased approach was devised, where one component in a binary co-crystal can be partially replaced by a third component, 25 in such a way that the molecules participating in (stronger) hydrogen bonding are left in place, while the weakly interacting molecules of the same kind are substituted by similarly shapes ones.…”

Bimodal nanoindentation response of the (001) face in crystalline sodium saccharin dihydrate

“…We examine two possible reasons for this. Sodium saccharin dihydrate belongs to a complex landscape [25][26][27][28][29] of hydrated and anhydrous forms and readily and nearly spontaneously converted into a lower hydrate, Na 3 (sac) 3 ·2H 2 O. [30].…”