Quaternary cocrystals: combinatorial synthetic strategies based on long-range synthon Aufbau modules (LSAM)

Abstract

A combinatorial synthetic approach is described for the isolation of quaternary cocrystals. The strategy outlines chemical and geometrical modulations in the long-range synthon Aufbau modules (LSAMs) to systematically increase the number of components.

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.…”

The Evolution Aspect in the Crystallization Process of [5,5′‐(HCF2CF2CH2OCH2)2‐2,2′‐bpy]MX2 (M = Pt, Pd; X = I, Br): Role of the Intramolecular CF2─H…X(─M) Hydrogen Bonds

“…A fine‐tuning of the structure was noticed between structures 5–6 and structure 7 , on the pattern of C─H … X and C─H … F(─C) supramolecular interactions, with the total number unchanged. These weak supramolecular interactions are likely related to the mechanisms for proof correction, achieved by the assembling interactions that are relatively weak during the reversible crystallization process. Structures 5 and 6 exhibit bifurcated [C─H … ] 2 F ─C on the F atom at Cγ position, whereas structure 7 shows the bifurcated C─ H [ … F─C] 2 hydrogen bonds on β‐CH 2 protons.…”

“…The terminal CF 2 ─H would behave as an H donor, taking advantage of the neighboring electronegative F atoms . The weak terminal C─H … F hydrogen bonds on the van der Waals limit (0.25 kcal/mol) were believed to contribute to the stability of crystal structures. The structural chemistry of 5 – 8 would further register the π stacking during the crystallization evolution.…”

Understanding geology through crystal engineering: coordination complexes, coordination polymers and metal–organic frameworks as minerals

“…Whereas the assembly of two-component crystals is today readily achieved by judicious choice of complementary functional groups on molecules, synthesizing cocrystals involving three or more components also requires consideration of other design principles, e.g. the relative strengths of acids and bases, or the use of mutually orthogonal interactions (Dubey et al, 2016;Topić & Rissanen, 2016;Bhogala & Nangia, 2008).…”