Fine tuning of crystal architecture by intermolecular interactions: synthon engineering

Abstract

There has been a long time effort to influence or favourably fine tune structural properties by introduction\ud of substituents or guest molecules of different sizes, shapes and chemical composition to consequently\ud alter physico-chemical properties of the respective crystals. These attempts require the recognition,\ud understanding and application of intermolecular interactions, crystallographic and, in case of occurrence,\ud non-crystallographic symmetries. It brings us to the field of crystal engineering, which aims to produce\ud new substances with required properties based on the knowledge of the structural properties of already\ud characterised solids. A series of calixarene crystal structures are presented where the crystal packing is\ud determined by spatial or by electrostatic effects. A series of laterally substituted calixarenes where both\ud steric requirements and electrostatic forces play a role in the crystal architecture shows how the supramolecular\ud synthon can be engineered

Methods for easy recognition of isostructurality – lab jack-like crystal structures of halogenated 2-phenylbenzimidazoles

“…[1][2][3] This can be achieved based on the knowledge of the molecular and supramolecular properties 4,5 and crystallographic and non-crystallographic symmetries. 6 Mastering the supramolecular packing architecture, in effect synthon engineering, 7,8 can be achieved through fine chemical changes. Firm transformation of crystal packing arrangements can be accomplished by influencing the electrostatic and steric properties by application of substituents, by changing their placement and/or chemical composition or by the use of compounds with a similar chemical composition in multi-component structures.…”

Isolating Equatorial and Oxo Based Influences on Uranyl Vibrational Spectroscopy in a Family of Hybrid Materials Featuring Halogen Bonding Interactions with Uranyl Oxo Atoms

“…Our understanding of crystal engineering in uranyl hybrid materials continues to mature,[1f], and our interest has evolved beyond efforts to promote extended structures via the use of noncovalent interactions to include synthon engineering, a process which tailors assembly to proceed via a synthon of choice. [3c], …”

Supramolecular interactions in the solid state

“…Supramolecular interactions control the path of molecular recognition, the set-up of the crystal packing arrangement, and in the case of flexible molecules the molecular conformation (Bombicz et al, 2014). A given packing arrangement might tolerate small molecular changes while keeping the related crystals isostructural.…”

“…The mastering of the supramolecular packing architecture, e.g. directed manipulation of molecular packing arrangement via the supramolecular interactions, can be appropriately described as synthon engineering (Bombicz et al, 2014).…”