From Solid‐State Structure and Dynamics to Crystal Engineering

Abstract

The investigation of the factors responsible for the stability of the diverse crystal forms that a given molecule can adopt in the solid state (polymorphs, hydrates, cocrystals, etc.) requires an appreciation of the relationship between static and dynamic behavior of atoms and molecules about equilibrium and far from equilibrium positions in the crystal structure. This is particularly relevant when dealing with molecules that are structurally nonrigid at ambient conditions in other media (solution, gas phase). The ease of motion of molecules in molecular crystals depends on the distribution of first neighboring molecules and on the network of intermolecular interactions, which are, in turn, also responsible for the relative thermodynamic stability of solid phases. The knowledge of the intermolecular interactions and of their interplay with the ionic char- [a]

Solid‐State Dynamics and High‐Pressure Studies of a Supramolecular Spiral Gear

“…The study of dynamic reorientational processes in crystals, [1] such as molecularr otations or librations,h as challenged scientists for decades in view of the unique nature of these phenomena, subverting the common perceptiono fc rystals as static entities. [2][3][4][5][6][7][8] Recently,ar enewed interest in the field was driven by the surge of artificial molecular machines.…”

Plasticity in zwitterionic drugs: the bending properties of Pregabalin and Gabapentin and their hydrates

“…transition, whereby a certain thermal energy is required for a molecule to rotate or vibrate between symmetry-related crystallographic positions (Lusi & Barbour, 2013;Braga et al, 2018). Here, the change occurs between two fully ordered structures instead.…”

Interplay of Halogen and Hydrogen Bonding in a Series of Heteroleptic iron(III) Complexes

“…[9][10][11][12][13] In contrast, the use of halogen bonding in coordination complexes, which are among the most diverse structures found in chemistry, remains comparatively unexplored. 14 In the studies that have been reported, three general strategies have emerged: firstly the design of ligands with an acceptor and donor in the same ligand (type i), [15][16][17] secondly cocrystals with either a neutral or cationic complex and halogen bonding donors (type ii) [18][19][20][21][22][23][24] and lastly complexes with two different ligands with one acting as the acceptor and the other the donor (type iii). The latter class typically uses halopyridine ligands and chelates such as -diketonates to balance the charge of the metal and satisfy the need for octahedral geometry.…”